MOTOROLA MMA1201P Sensor Datasheet

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Sensor
Device Data Book
DL200/D
Rev. 5, 01/2003
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DATA CLASSIFICATION
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This document contains information on a product in full production. Guaranteed limits will not be changed without
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MOTOROLA DEVICE CLASSIFICATIONS
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classified all devices into three categories: Preferred devices, Current products and Not Recommended for New
Design products.
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by virtue of their performance, price, functionality, or combination of attributes which offer the overall “best” value to
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identified as a “Motorola Preferred Device.’’
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because of the popularity and/or standardization or volume usage in current production designs. These products can
be acceptable for new designs but the preferred types are considered better alternatives for long term usage.
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The Sensor Data Book does not contain any
“Not Recommended for New Design” devices.
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Sensor
Device Data Book
The information in this book has been carefully reviewed and is believed to be accurate; however, no responsibility
is assumed for inaccuracies. Furthermore, this information does not convey to the purchaser of semiconductor
devices any license under the patent rights to the manufacturer.
Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation, or guarantee regarding the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and
all liability, including without limitation consequential or incidental damages. “Typical” parameters can and do vary in
different applications and actual performance may vary over time. All operating parameters, including “Typicals”, must
be validated for each customer application by customer’s technical experts. Motorola does not convey any license
under its patent rights nor the rights of others. Motorola products are not designed, intended, or authorized for use
as components in systems intended for surgical implant into the body, or other applications intended to support or
sustain life, or for any other application in which the failure of the Motorola product could create a situation where
personal injury or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola and its officers, employees, subsidiaries, affiliates,
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5th Edition
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TABLE OF CONTENTS
SECTION ONE — General Information
Quality and Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–2
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–2
Reliability Issues for Silicon Pressure Sensors . . . . . . 1–3
Soldering Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . 1–10
Pressure Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–11
Electrostatic Process Control . . . . . . . . . . . . . . . . . . 1–17
Statistical Process Control . . . . . . . . . . . . . . . . . . . . . . 1–11
Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–17
Accelerometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–17
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Media Compatibility Overview . . . . . . . . . . . . . . . . . . . 1–18
SECTION TWO — Acceleration Sensor Products
Mini Selector Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–2
Device Numbering System . . . . . . . . . . . . . . . . . . . . . . . 2–2
Sensor Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–3
Acceleration Sensor FAQ’s . . . . . . . . . . . . . . . . . . . . . . . 2–4
Data Sheets
MMA1200D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2– 5
MMA1201P . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–12
MMA1220D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2– 18
MMA1250D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–24
MMA1260D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–30
MMA1270D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–36
MMA2201D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2– 42
MMA2202D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2– 48
MMA3201D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2– 55
Application Notes
AN1559 Application Considerations for a Switched
Capacitor Accelerometer . . . . . . . . . . . . . 2– 62
AN1611 Impact and Tilt Measurement
Using Accelerometer . . . . . . . . . . . . . . . . . . 2–65
AN1612 Shock and Mute Pager Applications
Using Accelerometer . . . . . . . . . . . . . . . . . . 2–77
AN1632 MMA1201P Product Overview
and Interface Considerations . . . . . . . . . . 2– 84
AN1635 Baseball Pitch Speedometer . . . . . . . . . . . . 2– 89
AN1640 Reducing Accelerometer
Susceptibility to BCI . . . . . . . . . . . . . . . . . 2–101
AN1925 Using the Motorola Accelerometer
Evaluation Board . . . . . . . . . . . . . . . . . . . 2– 104
Case Outlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–107
Glossary of Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–109
SECTION THREE — Pressure Sensor Products
Mini Selector Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–2
Device Numbering System . . . . . . . . . . . . . . . . . . . . . . . 3–4
Package Offerings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–5
Orderable Part Numbers . . . . . . . . . . . . . . . . . . . . . . . . . 3–6
Pressure Sensor Overview
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–7
Motorola Pressure Sensors . . . . . . . . . . . . . . . . . . . . . . 3–8
Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–12
Sensor Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–13
Pressure Sensor FAQ’s . . . . . . . . . . . . . . . . . . . . . . . . 3–14
Data Sheets
MPX10, MPXV10GC Series . . . . . . . . . . . . . . . . . . . . 3–15
MPX12 Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–19
MPX2010, MPXV2010G Series . . . . . . . . . . . . . . . . . 3–23
MPX2050 Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–27
MPX2053, MPXV2053G Series . . . . . . . . . . . . . . . . . 3–31
MPX2100 Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–35
MPX2102, MPXV2102G Series . . . . . . . . . . . . . . . . . 3–39
MPX2200 Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–43
MPX2202, MPXV2202G Series . . . . . . . . . . . . . . . . . 3–47
MPX2300DT1, MPX2301DT1 . . . . . . . . . . . . . . . . . . . 3–51
MPX4080D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–54
MPX4100 Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–59
MPX4100A, MPXA4100A Series . . . . . . . . . . . . . . . . 3–64
MPX4101A MPXA4101A, MPXH6101A Series . . . . 3–70
MPX4105A Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–75
MPX4115A, MPXA4115A Series . . . . . . . . . . . . . . . . . 3–79
MPX4200A Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–84
MPX4250A, MPXA4250A Series . . . . . . . . . . . . . . . . 3–88
MPX4250D Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–93
MPX5010, MPXV5010G Series . . . . . . . . . . . . . . . . . 3–97
MPX5050, MPXV5050G Series . . . . . . . . . . . . . . . . 3–103
MPX5100 Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–108
MPX53, MPXV53GC Series . . . . . . . . . . . . . . . . . . . 3–114
MPX5500 Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–118
MPX5700 Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–122
MPX5999D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–126
MPXA6115A, MPXH6115A . . . . . . . . . . . . . . . . . . . . 3–130
MPXAZ4100A Series . . . . . . . . . . . . . . . . . . . . . . . . . 3–135
MPXAZ4115A Series . . . . . . . . . . . . . . . . . . . . . . . . . 3–140
MPXAZ6115A Series . . . . . . . . . . . . . . . . . . . . . . . . . 3–145
MPXC2011DT1, MPXC2012DT1 . . . . . . . . . . . . . . . 3–150
MPXH6300A Series . . . . . . . . . . . . . . . . . . . . . . . . . . 3–153
MPXM2010 Series . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–158
MPXM2053 Series . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–161
MPXM2102 Series . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–164
MPXM2202 Series . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–167
MPXV4006G Series . . . . . . . . . . . . . . . . . . . . . . . . . . 3–170
MPXV4115V Series . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–174
MPXV5004G Series . . . . . . . . . . . . . . . . . . . . . . . . . . 3–179
MPXV6115VC6U . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–183
Application Notes
AN935 Compensating for Nonlinearity in the
MPX10 Series Pressure Transducer . . . 3–188
AN936 Mounting Techniques, Lead Forming
and Testing of Motorola’s MPX Series
MPX10 Series Pressure Sensors . . . . . . 3–195
AN1082 Simple Design for a 3–20 mA Transmitter
Interface Using a Motorola
Pressure Sensor . . . . . . . . . . . . . . . . . . . . 3–200
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Table of Contents (continued)
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SECTION THREE (continued)
AN1097 Calibration–Free Pressure
Sensor System . . . . . . . . . . . . . . . . . . . . . .
AN1100 Analog to Digital Converter Resolution
Extension Using a Motorola
Pressure Sensor . . . . . . . . . . . . . . . . . . . .
AN1303 A Simple 3–20 mA Pressure
Transducer Evaluation Board . . . . . . . . .
AN1304 Integrated Sensor Simplifies Bar
Graph Pressure Gauge . . . . . . . . . . . . . . .
AN1305 An Evaluation System for Direct
Interface of the MPX5100 Pressure
Sensor with a Microprocessor . . . . . . . . .
AN1309 Compensated Sensor Bar Graph
Pressure Gauge . . . . . . . . . . . . . . . . . . . . .
AN1315 An Evaluation System Interfacing the
MPX2000 Series Pressure Sensors
to a Microprocessor . . . . . . . . . . . . . . . . . .
AN1316 Frequency Output Conversion for
MPX2000 Series Pressure Sensors . . . .
AN1318 Interfacing Semiconductor Pressure
Sensors to Microcomputers . . . . . . . . . . .
AN1322 Applying Semiconductor Sensors to
Bar Graph Pressure Gauges . . . . . . . . . .
AN1325 Amplifiers for Semiconductor
Pressure Sensors . . . . . . . . . . . . . . . . . . .
AN1326 Barometric Pressure Measurement
Using Semiconductor
Pressure Sensors . . . . . . . . . . . . . . . . . . .
AN1513 Mounting Techniques and Plumbing
Options of Motorola’s MPX Series
Pressure Sensors . . . . . . . . . . . . . . . . . . .
AN1516 Liquid Level Control Using a
Motorola Pressure Sensor . . . . . . . . . . . .
AN1517 Pressure Switch Design with
Semiconductor Pressure Sensors . . . . .
AN1518 Using a Pulse Width Modulated
Output with Semiconductor
Pressure Sensors . . . . . . . . . . . . . . . . . . .
AN1525 The A–B–C’s of Signal–Conditioning
Amplifier Design for
Sensor Applications . . . . . . . . . . . . . . . . . .
AN1536 Digital Boat Speedometers . . . . . . . . . . . . .
AN1551 Low Pressure Sensing with the
MPX2010 Pressure Sensor . . . . . . . . . . .
AN1556 Designing Sensor Performance
Specifications for
MCU–based Systems . . . . . . . . . . . . . . . .
AN1571 Digital Blood Pressure Meter . . . . . . . . . . . .
3–203
3–208
3–211
3–214
3–219
3–235
3–242
AN1573 Understanding Pressure
and Pressure Measurement . . . . . . . . . . .
AN1586 Designing a Homemade Digital Output
for Analog Voltage Output Sensors . . . . .
AN1636 Implementing Auto Zero for
Integrated Pressure Sensors . . . . . . . . . .
AN1646 Noise Considerations for Integrated
Pressure Sensors . . . . . . . . . . . . . . . . . . .
AN1660 Compound Coefficient Pressure Sensor
PSPICE Models . . . . . . . . . . . . . . . . . . . . .
AN1668 Washing Appliance Sensor Selection . . . . .
AN1950 Water Level Monitoring . . . . . . . . . . . . . . . . .
AN4007 New Small Amplified Automotive
Vacuum Sensors
A Single Chip Sensor Solution
for Brake Booster Monitoring . . . . . . . . . .
AN4010 Low–Pressure Sensing Using
MPX2010 Series Pressure Sensors . . . .
3–363
3–368
3–375
3–378
3–384
3–390
3–395
3–413
3–418
Case Outlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–423
3–269
Reference Information
Reference Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–439
Mounting and Handling Suggestions . . . . . . . . . . . . 3–441
Standard Warranty Clause . . . . . . . . . . . . . . . . . . . . . 3–442
3–279
Glossary of Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–443
3–263
Symbols, Terms, and Definitions . . . . . . . . . . . . . . . 3–446
3–284
SECTION FOUR — Safety and Alarm Integrated
Circuits
3–288
3–297
3–301
3–306
3–312
Mini Selector Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–2
Data Sheets
MC14467–1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4– 3
MC14468 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4– 9
MC14578 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4– 15
MC14600 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–19
MC145010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4– 24
MC145011 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4– 34
MC145012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4– 44
MC145017 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–54
MC145018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4– 60
3–318
3–325
Application Notes
AN1690 Alarm IC General Applications
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 4– 66
AN4009 Alarm IC Sample Applications . . . . . . . . . . . . 4–70
3–337
Case Outlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–72
3–346
3–355
SECTION FIVE — Alphanumeric Device Index
Alphanumeric Device Index . . . . . . . . . . . . . . . . . . . . . . 5–2
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Section One
General Information
Quality and Reliability . . . . . . . . . . . . . . . . . . . . . . . 1–2
Introduction:
This version of the Sensor Products Device Data Handbook is organized to provide easy reference to sensor device
information. We have reorganized the book based upon your
recommendations with our goal to make designing in pressure, acceleration and safety and alarm ICs easy, and if you
do have a question, you will have access to the technical
support you need.
The handbook is organized by product line, acceleration,
pressure and safety and alarm ICs. Once in a section, you
will find a glossary of terms, a list of frequently asked questions or other relevant data. If you have recommendations for
improvement, please complete the comment card and return
it to us or, feel free to call our Sensor Device Data Handbook
hot line and we will personally record your comments. The
hot line number is 480/413–3333. We look forward to hearing from you!
Motorola Sensor Device Data
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–2
Reliability Issues for Silicon Pressure Sensors . . . . 1–3
Soldering Precautions . . . . . . . . . . . . . . . . . . . . . . . . 1–10
Pressure Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–11
Electrostatic Process Control . . . . . . . . . . . . . . . . 1–11
Statistical Process Control . . . . . . . . . . . . . . . . . . . . 1–13
Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–17
Accelerometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–17
Media Compatability Overview . . . . . . . . . . . . . 1–18
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Quality and Reliability — Overview
A Major Objective of the Production Cycle
From rigid incoming inspection of piece parts and materials,
to stringent outgoing quality verification, the Motorola
assembly and process flow is encompassed by an elaborate
system of test and inspection stations; stations to ensure a
step-by-step adherence to prescribed procedure. This
produces the high level of quality for which Motorola is
known . . . from start to finish.
As illustrated in the process flow overview, every major
manufacturing step is followed by an appropriate in-process
quality inspection to insure product conformance to
specification. In addition, Statistical Process Control (S.P.C.)
techniques are utilized on all critical processes to insure
processing equipment is capable of producing the product to
the target specification while minimizing the variability.
Quality control in wafer processing, assembly, and final test
impart Motorola sensor products with a level of reliability that
easily exceeds almost all industrial, consumer, and military
requirements.
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Compensated Sensor Flow Chart
BINNING
CHECK
LASER I.D.
INITIAL
OXIDATION
1
P+ PHOTO
RESIST
2
RESISTOR
PHOTO
RESIST
EMITTER
PHOTO
RESIST
RESISTOR
IMPLANT
6
5
THIN-FILM
METAL DEP.
12
SAW AND
WASH
DIE SORT
AND LOAD
METAL
PHOTO
RESIST
CLASS
PROBE
WAFER
TO WAFER
BOND
15
CELL
MARKING
DIE BOND
AND CURE
17
LASER
TRIM
20
1–2
16
WIREBOND
18
100%
FUNCTIONAL
TEST
GEL FILL
AND CURE
9
FRONT
METAL
14
13
FINAL
OXIDATION
11
WAFER
FINAL
VISUAL
CAVITY
ETCH
4
8
7
10
CAVITY
PHOTO
RESIST
3
EMITTER
DIFFUSION
CONTACT
PHOTO
RESIST
THIN-FILM
METAL P.R.
P+
DIFFUSION
FINAL
VISUAL
21
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PACK AND
SHIP
22
23
Motorola Sensor Device Data
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Reliability Issues for Silicon Pressure Sensors
by Theresa Maudie and Bob Tucker
Sensor Products Division
Revised June 9, 1997
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ABSTRACT
Reliability testing for silicon pressure sensors is of
greater importance than ever before with the dramatic
increase in sensor usage. This growth is seen in applications replacing mechanical systems, as well as new
designs. Across all market segments, the expectation for
the highest reliability exists. While sensor demand has
grown across all of these segments, the substantial increase
of sensing applications in the automotive arena is driving
the need for improved reliability and test capability. The
purpose of this paper is to take a closer look at these reliability issues for silicon pressure sensors.
INTRODUCTION
Discussing reliability as it pertains to semiconductor electronics is certainly not a new subject. However, when developing new technologies like sensors how reliability testing
will be performed is not always obvious. Pressure sensors
are an intriguing dilemma. Since they are electromechanical
devices, different types of stresses should be considered to
insure the different elements are exercised as they would be
in an actual application. In addition, the very different
package outlines relative to other standard semiconductor
packages require special fixtures and test set-ups. However,
as the sensor marketplace continues to grow, reliability
testing becomes more important than ever to insure that
products being used across all market segments will meet
reliability lifetime expectations.
RELIABILITY DEFINITION
Reliability is [1] the probability of a product performing its
intended function over its intended lifetime and under the
operating conditions encountered. The four key elements of
the definition are probability, performance, lifetime, and
operating conditions. Probability implies that the reliability
lifetime estimates will be made based on statistical techniques where samples are tested to predict the lifetime of
the manufactured products. Performance is a key in that the
sample predicts the performance of the product at a given
point in time but the variability in manufacturing must be
controlled so that all devices perform to the same functional
level. Lifetime is the period of time over which the product is
intended to perform. This lifetime could be as small as one
week in the case of a disposable blood pressure transducer
or as long as 15 years for automotive applications. Environment is the area that also plays a key role since the operating conditions of the product can greatly influence the
reliability of the product.
Environmental factors that can be seen during the lifetime
of any semiconductor product include temperature, humidity,
electric field, magnetic field, current density, pressure differential, vibration, and/or a chemical interaction. Reliability
testing is generally formulated to take into account all of
these potential factors either individually or in multiple
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combinations. Once the testing has been completed predictions can be made for the intended product customer base.
If a failure would be detected during reliability testing, the
cause of the failure can be categorized into one of the
following: design, manufacturing, materials, or user. The
possible impact on the improvements that may need to be
made for a product is influenced by the stage of product
development. If a product undergoes reliability testing early
in its development phase, the corrective action process can
generally occur in an expedient manner and at minimum
cost. This would be true whether the cause of failure was
attributed to the design, manufacturing, or materials. If a
reliability failure is detected once the product is in full
production, changes can be very difficult to make and
generally are very costly. This scenario would sometimes
result in a total redesign.
The potential cause for a reliability failure can also be
user induced. This is generally the area that the least
information is known, especially for a commodity type
manufacturer that achieves sales through a global distribution network. It is the task of the reliability engineer to best
anticipate the multitudes of environments that a particular
product might see, and determine the robustness of the
product by measuring the reliability lifetime parameters.
The areas of design, manufacturing, and materials are
generally well understood by the reliability engineer, but
without the correct environmental usage, customer satisfaction can suffer from lack of optimization.
RELIABILITY STATISTICS
Without standardization of the semiconductor sensor standards, the end customer is placed in a situation of possible
jeopardy. If non-standard reliability data is generated and
published by manufacturers, the information can be
perplexing to disseminate and compare. Reliability lifetime
statistics can be confusing for the novice user of the information, “let the buyer beware”.
The reporting of reliability statistics is generally in terms of
failure rate, measured in FITs, or failure rate for one billion
device hours. In most cases, the underlying assumption
used in reporting either the failure rate or the MTBF is that
the failures occurring during the reliability test follow an exponential life distribution. The inverse of the failure rate is the
MTBF, or mean time between failure. The details on the
various life distributions will not be explored here but the key
concern about the exponential distribution is that the failure
rate over time is constant. Other life distributions, such as the
lognormal or Weibull can take on different failure rates over
time, in particular, both distributions can represent a wear out
or increasing failure rate that might be seen on a product
reaching the limitations on its lifetime or for certain types of
failure mechanisms.
The time duration use for the prediction of most reliability
statistics is of relatively short duration with respect to the
product’s lifetime ability and failures are usually not
observed. When a test is terminated after a set number of
hours is achieved, or time censored, and no failures are
observed, the failure rate can be estimated by use of the chisquare distribution which relates observed and expected
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new product and they have put a total of 1,000 parts on a
high temperature storage test for 500 hours each, their
corresponding cumulative device hours would be 500,000
device hours. Vendor B has been in the business for several
years on the same product and has tested a total of 500,000
parts for 10 hours each to the same conditions as part of an
in-line burn-in test for a total of 5,000,000 device hours. The
corresponding failure rate for a 60% confidence level for
vendor A would be 1,833 FITs, vendor B would have a FIT
rate of 183 FITs.
frequencies of an event to established confidence intervals.
The relationship between failure rate and the chi-square
distribution is as follows:
lL1
2
+ x ǒ a2t, d.f. Ǔ
Where:
=
=
=
=
=
=
=
failure rate
lower one side confidence limit
chi–square function
risk, (1–confidence level)
degrees of freedom = 2 (r + 1)
number of failures
device hours
Table 1. Chi-Square Table
Chi-Square Distribution Function
60% Confidence Level
Chi-square values for 60% and 90% confidence intervals
for up to 12 failures is shown in Table 1.
As indicated by the table, when no failures occur, an
estimate for the chi-square distribution interval is obtainable.
This interval estimate can then be used to solve for the
failure rate, as shown in the equation above. If no failures
occur, the failure rate estimate is solely a function of the
accumulated device hours. This estimate can vary dramatically as additional device hours are accumulated.
As a means of showing the influence of device hours with
no failures on the failure rate value, a graphical representation of cumulative device hours versus the failure rate
measured in FITs is shown in Figure 1.
A descriptive example between two potential vendors best
serves to demonstrate the point. If vendor A is introducing a
90% Confidence Level
No. Fails
χ2 Quantity
No. Fails
χ2 Quantity
0
1.833
0
4.605
1
4.045
1
7.779
2
6.211
2
10.645
3
8.351
3
13.362
4
10.473
4
15.987
5
12.584
5
18.549
6
14.685
6
21.064
7
16.780
7
23.542
8
18.868
8
25.989
9
20.951
9
28.412
10
23.031
10
30.813
11
25.106
11
33.196
12
27.179
12
35.563
109
108
107
FAILURE RATE, [FITs]
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λ
L1
χ2
α
d.f.
r
t
106
105
104
1,000
100
10
1
0.1
1
10
100
1,000
104
105
106
107
108
109
CUMULATIVE DEVICE HOURS, [t]
Figure 1. Depiction of the influence on the cumulative device hours with no failures
and the Failure Rate as measured in FITs.
1–4
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One could thus imply that the reliability performance
indicates that vendor B has an order of magnitude improvement in performance over vendor A with neither one seeing
an occurrence of failure during their performance.
The incorrect assumption of a constant failure rate over
time can potentially result in a less reliable device being
designed into an application. The reliability testing assumptions and test methodology between the various vendors
needs to be critiqued to insure a full understanding of the
product performance over the intended lifetime, especially in
the case of a new product. Testing to failure and determination of the lifetime statistics is beyond the scope of this paper
and presented elsewhere [2].
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INDUSTRY RELIABILITY STANDARDS
Reliability standards for large market segments are often
developed by “cross-corporation” committees that evaluate
the requirements for the particular application of interest. It is
the role of these committees to generate documents
intended as guides for technical personnel of the end users
and suppliers, to assist with the following functions: specifying, developing, demonstrating, calibrating, and testing the
performance characteristics for the specific application.
One such committee which has developed a standard for a
particular application is the Blood Pressure Monitoring
Committee of the Association for the Advancement of
Medical Instrumentation (AAMI) [3]. Their document, the
“American National Standard for Interchangeability and
Performance of Resistive Bridge Type Blood Pressure
Transducers”, has an objective to provide performance
requirements, test methodology, and terminology that will
help insure that safe, accurate blood pressure transducers
are supplied to the marketplace.
In the automotive arena, the Society of Automotive
Engineers (SAE) develops standards for various pressure
sensor applications such as SAE document J1346, “Guide to
Manifold Absolute Pressure Transducer Representative Test
Method” [4].
While these two very distinct groups have successfully
developed the requirements for their solid-state silicon
pressure sensor needs, no real standard has been set for the
general industrial marketplace to insure products being
offered have been tested to insure reliability under industrial
conditions. Motorola has utilized MIL-STD-750 as a reference document in establishing reliability testing practices for
the silicon pressure sensor, but the differences in the
technology between a discrete semiconductor and a silicon
pressure sensor varies dramatically. The additional tests that
are utilized in semiconductor sensor reliability testing are
based on the worst case operational conditions that the
device might encounter in actual usage.
ESTABLISHED SENSOR TESTING
Motorola has established semiconductor sensor reliability
testing based on exercising to detect failures by the
presence of the environmental stress. Potential failure
modes and causes are developed by allowing tests to run
beyond the normal test times, thus stressing to destruction.
The typical reliability test matrix used to insure conformance
to customers end usage is as follows [5]:
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PULSED PRESSURE TEMPERATURE CYCLING WITH
BIAS (PPTCB)
This test is an environmental stress test combined with
cyclic pressure loading in which the devices are alternately
subjected to a low and high temperature while operating under
bias under a cyclical pressure load. This test simulates the
extremes in the operational life of a pressure sensor. PPTCB
evaluates the sensor’s overall performance as well as
evaluating the die, die bond, wire bond and package integrity.
Typical Test Conditions: Temperature per specified
operating limits (i.e., Ta = –40 to 125°C for an automotive
application). Dwell time ≥ 15 minutes, transfer time ≤ 5
minutes, bias = 100% rated voltage. Pressure = 0 to full
scale, pressure frequency = 0.05 Hz, test time = up to 1000
hours.
Potential Failure Modes: Open, short, parametric shift.
Potential Failure Mechanisms: Die defects, wire bond
fatigue, die bond fatigue, port adhesive failure, volumetric
gel changes resulting in excessive package stress.
Mechanical creep of packaging material.
HIGH HUMIDITY, HIGH TEMPERATURE WITH BIAS
(H3TB)
A combined environmental/electrical stress test in which
devices are subjected to an elevated ambient temperature
and humidity while under bias. The test is useful for
evaluating package integrity as well as detecting surface
contamination and processing flaws.
Typical Test Conditions: Temperature between 60 and
85°C, relative humidity between 85 and 90%, rated voltage,
test time = up to 1000 hours.
Potential Failure Modes: Open, short, parametric shift.
Potential Failure Mechanisms: Shift from ionic affect,
parametric instability, moisture ingress resulting in excessive package stress, corrosion.
HIGH TEMPERATURE WITH BIAS (HTB)
This operational test exposes the pressure sensor to a
high temperature ambient environment in which the device is
biased to the rated voltage. The test is useful for evaluating
the integrity of the interfaces on the die and thin film stability.
Typical Test Conditions: Temperature per specified
operational maximum, bias = 100% rated voltage, test time
= up to 1000 hours.
Potential Failure Modes: Parametric shift in offset and/or
sensitivity.
Potential Failure Mechanisms: Bulk die or diffusion
defects, film stability and ionic contamination.
HIGH AND LOW TEMPERATURE STORAGE LIFE
(HTSL, LTSL)
High and low temperature storage life testing is performed
to simulate the potential shipping and storage conditions that
the pressure sensor might encounter in actual usage. The
test also evaluates the devices thermal integrity at worst
case temperatures.
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Typical Test Conditions: Temperature per specified
storage maximum and minimum, no bias, test time = up to
1000 hours.
Potential Failure Modes: Parametric shift in offset and/or
sensitivity.
Potential Failure Mechanisms: Bulk die or diffusion
defects, mechanical creep in packaging components due to
thermal mismatch.
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TEMPERATURE CYCLING (TC)
This is an environmental test in which the pressure sensor
is alternatively subjected to hot and cold temperature
extremes with a short stabilization time at each temperature
in an air medium. The test will stress the devices by
generating thermal mismatches between materials.
Typical Test Conditions: Temperature per specified
storage maximum and minimum (i.e., –40 to +125°C for
automotive applications). Dwell time ≥ 15 minutes, transfer
time ≤ 5 minutes, no bias. Test time up to 1000 cycles.
Potential Failure Modes: Open, parametric shift in offset
and/or sensitivity.
Potential Failure Mechanisms: Wire bond fatigue, die
bond fatigue, port adhesive failure, volumetric gel changes
resulting in excessive package stress. Mechanical creep of
packaging material.
MECHANICAL SHOCK
This is an environmental test where the sensor device is
evaluated to determine its ability to withstand a sudden
change in mechanical stress due to an abrupt change in
motion. This test simulates motion that may be seen in
handling, shipping or actual use. MIL STD 750, Method 2016
Reference.
Typical Test Conditions: Acceleration = 1500 g’s, orientation = X, Y, Z planes, time = 0.5 milliseconds, 5 blows.
Potential Failure Modes: Open, parametric shift in offset
and/or sensitivity.
Potential Failure Mechanisms: Diaphragm fracture,
mechanical failure of wire bonds or package.
VARIABLE FREQUENCY VIBRATION
A test to examine the ability of the pressure sensor device
to withstand deterioration due to mechanical resonance. MIL
STD 750, Method 2056 Reference.
Typical Test Conditions: Frequency – 10 Hz to 2 kHz, 6.0
G’s max, orientation = X, Y, Z planes, 8 cycles each axis, 2
hrs. per cycle.
Potential Failure Modes: Open, parametric shift in offset
and/or sensitivity.
Potential Failure Mechanisms: Diaphragm fracture,
mechanical failure of wire bonds or package.
SOLDERABILITY
In this reliability test, the lead/terminals are evaluated for
their ability to solder after an extended time period of storage
(shelf life). MIL STD 750, Method 2026 Reference.
1–6
Typical Test Conditions: Steam aging = 8 hours, Flux= R,
Solder = Sn63, Pb37.
Potential Failure Modes: Pin holes, non–wetting,
dewetting.
Potential Failure Mechanisms: Poor plating, contamination.
OVER PRESSURE
This test is performed to measure the ability of the
pressure sensor to withstand excessive pressures that may
be encountered in the application. The test is performed from
either the front or back side depending on the application.
Typical Test Conditions: Pressure increase to failure,
record value.
Potential Failure Modes: Open.
Potential Failure Mechanisms: Diaphragm fracture,
adhesive or cohesive failure of die attach.
A pressure sensor may be placed in an application where
it will be exposed to various media that may chemically
attack the active circuitry, silicon, interconnections and/or
packaging material. The focus of media compatibility is to
understand the chemical impact with the other environmental
factors such as temperature and bias and determine the
impact on the device lifetime. The primary driving mechanism to consider is permeation which quantifies the time for a
chemical to permeate across a membrane or encapsulant
corrosion can result.
Media related product testing is generally very specific to
the application since the factors that relate to the product
lifetime are very numerous and varied. An example is
solution pH where the further from neutral will drive the
chemical reaction, generally to a power rule relationship. The
pH alone does not always drive the reaction either, the
non–desired products in the media such as strong acids in
fuels as a result of acid rain can directly influence the lifetime.
It is recommended the customer and/or vendor perform
application specific testing that best represents the environment. This testing should be performed utilizing in situ
monitoring of the critical device parameter to insure the
device survives while exposed to the chemical. The Sensor
Products Division within Motorola has a wide range of media
specific test capabilities and under certain circumstances will
perform application specific media testing.
A sufficient sample size manufactured over a pre-defined
time interval to maximize process and time variability is
tested based on the guidelines of the matrix shown above.
This test methodology is employed on all new product
introductions and process changes on current products.
A silicon pressure sensor has a typical usage environment of pressure, temperature, and voltage. Unlike the
typical bipolar transistor life tests which incorporate current
density and temperature to accelerate failures, a silicon
pressure sensor’s acceleration of its lifetime performance is
primarily based on the pressure and temperature interaction with a presence of bias. This rationale was incorporated
into the development of the Pulsed Pressure Temperature
Cycling with Bias (PPTCB) test where the major acceleration factor is the pressure and temperature component. It is
also why PPTCB is considered the standard sensor
operational life test.
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To insure that silicon pressure sensors are designed and
manufactured for reliability, an in-depth insight into what
mechanisms cause particular failures is required. It is safe to
say that unless a manufacturer has a clear understanding of
everything that can go wrong with the device, it cannot
design a device for the highest reliability. Figure 2 provides a
look into the sensor operating concerns for a variety of
potential usage applications. This information is utilized
when developing the Failure Mode and Effects Analysis
(FMEA). The FMEA then serves as the documentation that
demonstrates all design and process concerns have been
addressed to offer the most reliable approach. By understanding how to design products, control processes, and
eliminate the concerns raised, a reliable product is achieved.
ACCELERATED LIFE TESTING
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It is very difficult to assess the reliability statistics for a
product when very few or no failures occur. With cost as a
predominant factor in any industrial setting and time of the
utmost importance, the reliability test must be optimized.
Optimization of reliability testing will allow the maximum
amount of information on the product being tested to be
gained in a minimum amount of time, this is accomplished by
using accelerated life testing techniques.
A key underlying assumption in the usage of accelerated
life testing to estimate the life of a product at a lower or
nominal stress is that the failure mechanism encountered
at the high stress is the same as that encountered at the
nominal stress. The most frequently applied accelerated
environmental stress for semiconductors is temperature, it
will be briefly explained here for its utilization in determining the lifetime reliability statistics for silicon pressure
sensors.
SENSOR RELIABILITY CONCERNS
GEL:
Viscosity
Thermal Coefficient of Expansion
Permeability (Diffusion x Solubility)
Changes in Material or Process
Height
Coverage
Uniformity
Adhesive Properties
Media Compatibility
Gel Aeration
Compressibility
PACKAGE:
Integrity
Plating Quality
Dimensions
Thermal Resistance
Mechanical Resistance
Pressure Resistance
Media Compatibility
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÄÄÄÄÄÄÄÄÄÄ
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
BONDING WIRES:
Strength
Placement
Height and Loop
Size
Material
Bimetallic Contamination
(Kirkendall Voids)
Nicking and other damage
General Quality & Workmanship
LEADS:
Materials and Finish
Plating Integrity
Solderability
General Quality
Strength
Contamination
Corrosion
Adhesion
MARKING:
Permanency
Clarity
DIE ATTACH:
Uniformity
Resistance to Mechanical Stress
Resistance to Temperature Stress
Wetting
Adhesive Strength
Cohesive Strength
Process Controls
Die Orientation
Die Height
Change in Material or Process
Media Compatibility
Compressibility
DIE
METALLIZATION:
Lifting or Peeling
Alignment
Scratches
Voids
Laser Trimming
Thickness
Step Coverage
Contact Resistance Integrity
DIAPHRAGM:
Size
Thickness
Uniformity
Pits
Alignment
Fracture
PASSIVATION:
Thickness
Mechanical Defects
Integrity
Uniformity
ELECTRICAL PERFORMANCE:
Continuity and Shorts
Parametric Stability
Parametric Performance
Temperature Performance
Temperature Stability
Long Term Reliability
Storage Degradation
Susceptibility to Radiation Damage
Design Quality
DESIGN CHANGES
MATERIAL OR PROCESS
CHANGES
FAB & ASSEMBLY CLEANLINESS
SURFACE CONTAMINATION
FOREIGN MATERIAL
SCRIBE DEFECTS
DIFFUSION DEFECTS
OXIDE DEFECTS
Figure 2. Process and Product Variability Concerns During Reliability Testing
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The temperature acceleration factor for a particular failure
mechanism can be related by taking the ratio for the reaction
rate of the two different stress levels as expressed by the
Arrhenius type of equation. The mathematical derivation of
the first order chemical reaction rate computes to:
(RT)HS
tHS
AF
tLS
(RT)LS
+
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AF
Where:
AF
RT
t
T
Ea
=
=
=
=
=
k
LS
HS
=
=
=
+ exp
+
ƪ ǒ * Ǔƫ
Ea
k
1
TLS
1
THS
Acceleration Factor
Reaction Rate
time
temperature [°K]
activation energy of expressed
in electron-volts [eV]
Boltzman’s constant, 8.6171 x 10-5 eV/°K
Low stress or nominal temperature
High stress or test temperature
The activation energy is dependent on the failure mechanism and typically varies from 0.3 to 1.8 electron-volts. The
activation energy is directly proportional to the degree of
influence that temperature has on the chemical reaction rate.
A listing of typical activation energies is included in reference
[6] and [7].
An example using the Arrenhius equation will be demonstrated. A 32 device HTB test for 500 hours total and no
failure was performed. The 125°C, 100% rated voltage test
resulted in no failures. If a customer ’s actual usage
conditions was 55°C at full rated voltage, an estimate of the
lower one side confidence limit can be calculated. An
assumption is made that the failure rate is constant thus
implying the exponential distribution. The first step is to
calculate the equivalent device hours for the customer’s use
conditions by solving for the acceleration factor.
From the acceleration factor above, if eA is assumed equal
to 1,
AF
1–8
+ exp
ƪ ǒ * Ǔƫ
Ea
k
1
TLS
1
THS
Where:
eA
TLS
THS
then;
AF
=
=
=
0.7eV/°K (assumed)
55°C + 273.16 = 328.16°K
125°C + 273.16 = 398.16°K
=
77.64
Therefore, the equivalent cumulative device hours at the
customer’s use condition is:
tLS
=
AF x tHS = (32 500) 77.64
or
tLS
=
1,242,172 device hours
Computing the lower one sided failure rate with a 90% confidence level and no failures:
x2 (a, d.f.)
l
2t
or
λ
=
1.853E–06 failures per hour
or
λ
=
1,853 FITs
+
The inverse of the failure, λ, or the Mean Time To Failure
(MTTF) is:
1
MTTF
l
or
MTTF = 540,000 device hours
+
CONCLUSION
Reliability testing durations and acceptance numbers are
used as a baseline for achieving adequate performance in
the actual use condition that the silicon pressure sensor
might encounter. The baseline for reliability testing can be
related to the current record high jump bar height. Just as
athletes in time achieve a higher level of performance by
improvements in their level of physical and mental fitness,
silicon pressure sensors must also incorporate improvements in the design, materials, and manufacturability to
achieve the reliability growth demands the future market
place will require. This philosophy of never ending improvement will promote consistent conformance to the customer’s
expectation and production of a best in class product.
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REFERENCES
[4] “Interchangeability and Performance of Resistive Bridge
Type Blood Pressure Transducers,” AAMI Guideline,
Blood Pressure Monitoring Committee, latest revision.
[5] “Motorola D.M.T.G. Reliability Audit Report,” Q191.
[6] Wayne Nelson, “Accelerated Testing: Statistical
Models,” Test Plans, and Data Analyses, John Wiley &
Sons, Inc., New York, N.Y., 1990.
[7] D.S. Peck and O.D. Trapp, (1978), “Accelerated Testing
Handbook,” Technology Associates, revised 1987.
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[1] Dr. Joseph E. Matar and Theresa Maudie, “Reliability
Engineering and Accelerated Life Testing,” Motorola
Internal Training Text, 1989.
[2] D.J. Monk, T. Maudie, D. Stanerson, J. Wertz, G. Bitko,
J. Matkin, and S. Petrovic, “Media Compatible
Packaging and Environmental Testing of Barrier Coating
Encapsulated Silicon Pressure Sensors,’’ 1996,
Solid–State Sensors and Actuators Workshop. Hilton
Head, SC, pp. 36–41, 1996.
[3] “Guide to Manifold Absolute Pressure Transducer
Representative Test Method,” SAE Guideline J1346,
Transducer Subcommittee, latest revision.
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SOLDERING PRECAUTIONS
The melting temperature of solder is higher than the rated
temperature of the device. When the entire device is heated
to a high temperature, failure to complete soldering within a
short time could result in device failure. Therefore, the
following items should always be observed in order to minimize the thermal stress to which the devices are subjected.
• Always preheat the device.
• The delta temperature between the preheat and soldering
should be 100°C or less.*
• For pressure sensor devices, a no–clean solder is
recommended unless the silicone die coat is sealed and
unexposed. Also, prolonged exposure to fumes can
damage the silicone die coat of the device during the solder
reflow process.
• When preheating and soldering, the temperature of the
leads and the case must not exceed the maximum
temperature ratings as shown on the data sheet. When
•
•
•
•
using infrared heating with the reflow soldering method, the
difference should be a maximum of 10°C.
The soldering temperature and time should not exceed
260°C for more than 10 seconds.
When shifting from preheating to soldering, the maximum
temperature gradient shall be 5°C or less.
After soldering has been completed, the device should be
allowed to cool naturally for at least three minutes. Gradual
cooling should be used since the use of forced cooling will
increase the temperature gradient and will result in latent
failure due to mechanical stress.
Mechanical stress or shock should not be applied during
cooling.
* Soldering a device without preheating can cause excessive
thermal shock and stress which can result in damage to the
device.
TYPICAL SOLDER HEATING PROFILE
For any given circuit board, there will be a group of control
settings that will give the desired heat pattern. The operator
must set temperatures for several heating zones and a figure
for belt speed. Taken together, these control settings make
up a heating “profile” for that particular circuit board. On
machines controlled by a computer, the computer remembers these profiles from one operating session to the next.
Figure 3 shows a typical heating profile for use when
soldering a surface mount device to a printed circuit board.
This profile will vary among soldering systems, but it is a
good starting point. Factors that can affect the profile include
the type of soldering system in use, density and types of
components on the board, type of solder used, and the type
of board or substrate material being used. This profile shows
temperature versus time. The line on the graph shows the
STEP 1
PREHEAT
ZONE 1
“RAMP”
200°C
STEP 2 STEP 3
VENT
HEATING
“SOAK” ZONES 2 & 5
“RAMP”
DESIRED CURVE FOR HIGH
MASS ASSEMBLIES
actual temperature that might be experienced on the surface
of a test board at or near a central solder joint. The two
profiles are based on a high density and a low density board.
The Vitronics SMD310 convection/infrared reflow soldering
system was used to generate this profile. The type of solder
used was 62/36/2 Tin Lead Silver with a melting point
between 177 –189°C. When this type of furnace is used for
solder reflow work, the circuit boards and solder joints tend to
heat first. The components on the board are then heated by
conduction. The circuit board, because it has a large surface
area, absorbs the thermal energy more efficiently, then
distributes this energy to the components. Because of this
effect, the main body of a component may be up to 30
degrees cooler than the adjacent solder joints.
STEP 4
HEATING
ZONES 3 & 6
“SOAK”
STEP 5
HEATING
ZONES 4 & 7
“SPIKE”
STEP 6
VENT
STEP 7
COOLING
205° TO 219°C
PEAK AT
SOLDER JOINT
170°C
160°C
150°C
150°C
100°C
140°C
100°C
SOLDER IS LIQUID FOR
40 TO 80 SECONDS
(DEPENDING ON
MASS OF ASSEMBLY)
DESIRED CURVE FOR LOW
MASS ASSEMBLIES
50°C
TIME (3 TO 7 MINUTES TOTAL)
TMAX
Figure 3. Typical Solder Heating Profile
1–10
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Freescale Semiconductor, Inc...
Electrostatic Discharge Data
Electrostatic damage (ESD) to semiconductor devices has
plagued the industry for years. Special packaging and
handling techniques have been developed to protect these
sensitive devices. While many of Motorola’s semiconductors
devices are not susceptible to ESD, all products are revered
as sensitive and handled accordingly.
The data in this section was developed using the
human-body model specified in MIL-STD-750C, Method
1020. The threshold values (Eth, kV) of ten devices was
recorded, then the average value calculated. This data plus
the device type, device source, package type, classification,
polarity and general device description are supplied. Devices
listed are mainly JEDEC registered 1N and 2N numbers.
Military QPL devices and some customer specials are also in
this database. The data in this report will be updated
regularly, and the range will be added as new data becomes
available.
The sensitivity classifications listed are as follows:
Class 1 . . .1 to 1999 volts
The code “N/S” signifies a non-sensitive device. “SEN” are
considered sensitive and should be handled according to
ESD procedures. Of the various products manufactured by
the Communications, Power and Signal Technologies
Group, the following examples list general device families by
not sensitive to extremely sensitive.
Not sensitive . . . . . . FET current regulators
Least sensitive . . . . Zener diodes (on a square
mil/millijoule basis)
Less sensitive . . . . . Bipolar transistors
More sensitive . . . . Bipolar darlington transistors
Very sensitive . . . . . Power TMOS devices
Extremely sensitive Hot carrier diodes and MOSFET
transistors without gate protection
The data supplied herein, is listed in numerical or
alphabetical order.
Class 2 . . .2000 to 3999 volts
DEVICE
Class 3 . . .4000 to > 15500 volts
LINE
CASE
CLASS
PRODUCT DESCRIPTION
MPX10D
XL0010V1
344–15
3–SEN
Uncompensated
MPX10DP
XL0010V1
344C–01
3–SEN
Uncompensated
MPX10GP
XL0010V1
344B–01
3–SEN
Uncompensated
MPX12D
XL0012V1
344–15
3–SEN
Uncompensated
MPX12DP
XL0012V1
344C–01
3–SEN
Uncompensated
MPX12GP
XL0012V1
344B–01
3–SEN
Uncompensated
MPX2010D
XL2010V5
344–15
1–SEN
Temperature Compensated/Calibrated
MPX2010DP
XL2010V5
344C–01
1–SEN
Temperature Compensated/Calibrated
MPX2010GP
XL2010V5
344B–01
1–SEN
Temperature Compensated/Calibrated
MPX2010GS
XL2010V5
344E–01
1–SEN
Temperature Compensated/Calibrated
MPX2010GSX
XL2010V5
344F–01
1–SEN
Temperature Compensated/Calibrated
MPX2300DT1
XL2300C1,01C1
423–05
1–SEN
Temperature Compensated/Calibrated
MPX4100A
XL4101S2
867–08
1–SEN
Signal–Conditioned
MPX4100AP
XL4101S2
867B–04
1–SEN
Signal–Conditioned
MPX4100AS
XL4101S2
867E–03
1–SEN
Signal–Conditioned
MPX4101A
XL4101S2
867–08
1–SEN
Signal–Conditioned
MPX4115A
XL4101S2
867–08
1–SEN
Signal–Conditioned
MPX4115AP
XL4101S2
867B–04
1–SEN
Signal–Conditioned
MPX4115AS
XL4101S2
867E–03
1–SEN
Signal–Conditioned
MPX4250A
XL4101S2
867–08
1–SEN
Signal–Conditioned
MPX4250AP
XL4101S2
867B–04
1–SEN
Signal–Conditioned
MPX5010D
XL4010S5
867–08
1–SEN
Signal–Conditioned
MPX5010DP
XL4010S5
867C–05
1–SEN
Signal–Conditioned
MPX5010GP
XL4010S5
867B–04
1–SEN
Signal–Conditioned
MPX5010GS
XL4010S5
867E–03
1–SEN
Signal–Conditioned
MPX5010GSX
XL4010S5
867F–03
1–SEN
Signal–Conditioned
Motorola Sensor Device Data
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Freescale Semiconductor, Inc.
DEVICE
LINE
CASE
CLASS
PRODUCT DESCRIPTION
XL4051S1
867–08
1–SEN
Signal–Conditioned
MPX5050DP
XL4051S1
867C–05
1–SEN
Signal–Conditioned
MPX5050GP
XL4051S1
867B–04
1–SEN
Signal–Conditioned
MPX5100D
XL4101S1
867–08
1–SEN
Signal–Conditioned
MPX5100DP
XL4101S1
867C–05
1–SEN
Signal–Conditioned
MPX5100GP
XL4101S1
867B–04
1–SEN
Signal–Conditioned
MPX5700D
XL4701S1
867–08
1–SEN
Signal–Conditioned
MPX5700DP
XL4701S1
867C–05
1–SEN
Signal–Conditioned
MPX5700GP
XL4701S1
867B–04
1–SEN
Signal–Conditioned
MPX5999D
XL4999S1
867–08
1–SEN
Signal–Conditioned
Freescale Semiconductor, Inc...
MPX5050D
1–12
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Freescale Semiconductor, Inc...
Statistical Process Control
Motorola’s Semiconductor Products Sector is continually
pursuing new ways to improve product quality. Initial design
improvement is one method that can be used to produce a
superior product. Equally important to outgoing product
quality is the ability to produce product that consistently
conforms to specification. Process variability is the basic
enemy of semiconductor manufacturing since it leads to
product variability. Used in all phases of Motorola’s product
manufacturing, STATISTICAL PROCESS CONTROL (SPC)
replaces variability with predictability. The traditional philosophy in the semiconductor industry has been adherence to
the data sheet specification. Using SPC methods assures
the product will meet specific process requirements
throughout the manufacturing cycle. The emphasis is on
defect prevention, not detection. Predictability through SPC
methods requires the manufacturing culture to focus on
constant and permanent improvements. Usually these
improvements cannot be bought with state-of-the-art equipment or automated factories. With quality in design, process
and material selection, coupled with manufacturing predictability, Motorola produces world class products.
The immediate effect of SPC manufacturing is predictability through process controls. Product centered and
distributed well within the product specification benefits
Motorola with fewer rejects, improved yields and lower cost.
The direct benefit to Motorola’s customers includes better
incoming quality levels, less inspection time and ship-tostock capability. Circuit performance is often dependent on
the cumulative effect of component variability. Tightly
controlled component distributions give the customer greater
circuit predictability. Many customers are also converting to
just-in-time (JIT) delivery programs. These programs require
improvements in cycle time and yield predictability achievable only through SPC techniques. The benefit derived from
SPC helps the manufacturer meet the customer’s expectations of higher quality and lower cost product.
Ultimately, Motorola will have Six Sigma capability on all
products. This means parametric distributions will be
centered within the specification limits with a product
distribution of plus or minus Six Sigma about mean. Six
Sigma capability, shown graphically in Figure 1, details the
benefit in terms of yield and outgoing quality levels. This
compares a centered distribution versus a 1.5 sigma worst
case distribution shift.
New product development at Motorola requires more
robust design features that make them less sensitive to
minor variations in processing. These features make the
implementation of SPC much easier.
A complete commitment to SPC is present throughout
Motorola. All managers, engineers, production operators,
supervisors and maintenance personnel have received
multiple training courses on SPC techniques. Manufacturing has identified 22 wafer processing and 8 assembly
steps considered critical to the processing of semiconductor
products. Processes, controlled by SPC methods, that have
shown significant improvement are in the diffusion, photolithography and metallization areas.
Motorola Sensor Device Data
-6σ -5σ -4σ -3σ -2σ -1σ
0
1σ
2σ 3σ 4σ
5σ 6σ
Standard Deviations From Mean
Distribution Centered
At ± 3 σ 2700 ppm defective
99.73% yield
At ± 4 σ 63 ppm defective
99.9937% yield
At ± 5 σ 0.57 ppm defective
99.999943% yield
At ± 6 σ 0.002 ppm defective
99.9999998% yield
Distribution Shifted ± 1.5
66810 ppm defective
93.32% yield
6210 ppm defective
99.379% yield
233 ppm defective
99.9767% yield
3.4 ppm defective
99.99966% yield
Figure 1. AOQL and Yield from a Normal
Distribution of Product With 6σ Capability
To better understand SPC principles, brief explanations
have been provided. These cover process capability, implementation and use.
PROCESS CAPABILITY
One goal of SPC is to ensure a process is CAPABLE.
Process capability is the measurement of a process to
produce products consistently to specification requirements.
The purpose of a process capability study is to separate the
inherent RANDOM VARIABILITY from ASSIGNABLE
CAUSES. Once completed, steps are taken to identify and
eliminate the most significant assignable causes. Random
variability is generally present in the system and does not
fluctuate. Sometimes, these are considered basic limitations
associated with the machinery, materials, personnel skills or
manufacturing methods. Assignable cause inconsistencies
relate to time variations in yield, performance or reliability.
Traditionally, assignable causes appear to be random due
to the lack of close examination or analysis. Figure 2 shows
the impact on predictability that assignable cause can have.
Figure 3 shows the difference between process control and
process capability.
A process capability study involves taking periodic
samples from the process under controlled conditions. The
performance characteristics of these samples are charted
against time. In time, assignable causes can be identified
and engineered out. Careful documentation of the process is
key to accurate diagnosis and successful removal of the
assignable causes. Sometimes, the assignable causes will
remain unclear requiring prolonged experimentation.
Elements which measure process variation control and
capability are Cp and Cpk respectively. Cp is the
specification width divided by the process width or Cp =
(specification width) / 6σ. Cpk is the absolute value of the
closest specification value to the mean, minus the mean,
divided by half the process width or Cpk = | closest
specification – X /3σ .
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PREDICTION
In control assignable
causes eliminated
TIME
TIME
Out of control
(assignable causes present)
SIZE
Process “under control” – all assignable causes are
removed and future distribution is predictable.
SIZE
? ?
Freescale Semiconductor, Inc...
?
? ?
?
?
? ?
?
?
PREDICTION
Lower
Specification Limit
Upper
Specification Limit
In control and capable
(variation from random
TIME
variability reduced)
TIME
SIZE
Figure 2. Impact of Assignable Causes on
Process Predictable
At Motorola, for critical parameters, the process capability
is acceptable with a Cpk = 1.33. The desired process
capability is a Cpk = 2 and the ideal is a Cpk = 5. Cpk, by
definition, shows where the current production process fits
with relationship to the specification limits. Off center
distributions or excessive process variability will result in less
than optimum conditions
SPC IMPLEMENTATION AND USE
DMTG uses many parameters that show conformance to
specification. Some parameters are sensitive to process
variations while others remain constant for a given product
line. Often, specific parameters are influenced when
changes to other parameters occur. It is both impractical and
unnecessary to monitor all parameters using SPC methods.
Only critical parameters that are sensitive to process
variability are chosen for SPC monitoring. The process steps
affecting these critical parameters must be identified also. It
is equally important to find a measurement in these process
steps that correlates with product performance. This is
called a critical process parameter.
Once the critical process parameters are selected, a
sample plan must be determined. The samples used for
measurement are organized into RATIONAL SUBGROUPS
of approximately 2 to 5 pieces. The subgroup size should be
such that variation among the samples within the subgroup
remain small. All samples must come from the same source
e.g., the same mold press operator, etc.. Subgroup data
should be collected at appropriate time intervals to detect
variations in the process. As the process begins to show
1–14
SIZE
In control but not capable
(variation from random variability
excessive)
Figure 3. Difference Between Process
Control and Process Capability
improved stability, the interval may be increased. The data
collected must be carefully documented and maintained for
later correlation. Examples of common documentation
entries would include operator, machine, time, settings,
product type, etc.
Once the plan is established, data collection may begin.
The data collected will generate X and R values that are
plotted with respect to time. X refers to the mean of the
values within a given subgroup, while R is the range or
greatest value minus least value. When approximately 20 or
more X and R values have been generated, the average of
these values is computed as follows:
X = ( X + X2 + X 3 + ...)/K
R = (R1 + R2 + R3 + ...)/K
where K = the number of subgroups measured.
The values of X and R are used to create the process
control chart. Control charts are the primary SPC tool used
to signal a problem. Shown in Figure 4, process control
charts show X and R values with respect to time and
concerning reference to upper and lower control limit values.
Control limits are computed as follows:
+ UCLR + D4 R
R lower control limit + LCL + D3 R
R
X upper control limit + UCL + ) A2 R
X
X
X lower control limit + LCL + * A2 R
X
X
R upper control limit
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Motorola Sensor Device Data
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
Freescale Semiconductor, Inc.
154
153
UCL = 152.8
152
151
X = 150.4
150
149
148
LCL = 148.0
147
UCL = 7.3
7
6
5
Freescale Semiconductor, Inc...
4
R = 3.2
3
2
1
LCL = 0
0
Figure 4. Example of Process Control Chart Showing Oven Temperature Data
Where D4, D3 and A2 are constants varying by sample
size,with values for sample sizes from 2 to 10 shown in the
following partial table:
n
2
3
4
5
6
7
8
9
10
D4
3.27
2.57
2.28
2.11
2.00
1.92
1.86
1.82
1.78
D3
*
*
*
*
*
0.08
0.14
0.18
0.22
A2
1.88
1.02
0.73
0.58
0.48
0.42
0.37
0.34
0.31
* For sample sizes below 7, the LCLR would technically be
a negative number; in those cases there is no lower control
limit; this means that for a subgroup size 6, six “identical”
measurements would not be unreasonable.
Control charts are used to monitor the variability of critical
process parameters. The R chart shows basic problems with
piece to piece variability related to the process. The X chart
can often identify changes in people, machines, methods,
etc. The source of the variability can be difficult to find and
may require experimental design techniques to identify
assignable causes.
Some general rules have been established to help determine when a process is OUT-OF-CONTROL. Figure 5 shows
a control chart subdivided into zones A, B, and C corresponding to 3 sigma, 2 sigma, and 1 sigma limits respectively.
In Figure 6 through Figure 9 four of the tests that can be used
to identify excessive variability and the presence of assignable
causes are shown. As familiarity with a given process
increases, more subtle tests may be employed successfully.
Once the variability is identified, the cause of the variability
must be determined. Normally, only a few factors have a significant impact on the total variability of the process. The importance of correctly identifying these factors is stressed in the
following example. Suppose a process variability depends on
the variance of five factors A, B, C, D and E. Each has a variance of 5, 3, 2, 1 and 0.4 respectively.
Motorola Sensor Device Data
+ Ǹs A2 ) s B2 ) s C2 ) s D2 ) s E2
s tot + 52 ) 32 ) 2 2 ) 12 ) (0.4) 2 + 6.3
Since:
s tot
Ǹ
+Ǹ
Now if only D is identified and eliminated then;
s tot
52
) 32 ) 22 ) (0.4)2 + 6.2
This results in less than 2% total variability improvement.
If B, C and D were eliminated, then;
s tot
+
Ǹ
52
) (0.4)2 + 5.02
This gives a considerably better improvement of 23%. If
only A is identified and reduced from 5 to 2, then;
s tot
+
Ǹ
22
) 32 ) 22 ) 12 ) (0.4)2 + 4.3
Identifying and improving the variability from 5 to 2 gives
us a total variability improvement of nearly 40%.
Most techniques may be employed to identify the primary
assignable cause(s). Out-of-control conditions may be
correlated to documented process changes. The product
may be analyzed in detail using best versus worst part
comparisons or Product Analysis Lab equipment. Multi-variance analysis can be used to determine the family of variation (positional, critical or temporal). Lastly, experiments may
be run to test theoretical or factorial analysis. Whatever
method is used, assignable causes must be identified and
eliminated in the most expeditious manner possible.
After assignable causes have been eliminated, new
control limits are calculated to provide a more challenging
variability criteria for the process. As yields and variability
improve, it may become more difficult to detect improvements because they become much smaller. When all
assignable causes have been eliminated and the points
remain within control limits for 25 groups, the process is said
to be in a state of control.
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UCL
UCL
A
ZONE A (+ 3 SIGMA)
B
ZONE B (+ 2 SIGMA)
C
ZONE C (+ 1 SIGMA)
CENTERLINE
ZONE C (– 1 SIGMA)
C
ZONE B (– 2 SIGMA)
B
A
ZONE A (– 3 SIGMA)
LCL
Figure 5. Control Chart Zones
Figure 6. One Point Outside Control Limit
Indicating Excessive Variability
Freescale Semiconductor, Inc...
UCL
UCL
A
A
B
B
C
C
C
C
B
B
A
LCL
A
LCL
Figure 7. Two Out of Three Points in Zone A
or Beyond Indicating Excessive Variability
LCL
Figure 8. Four Out of Five Points in Zone B or
Beyond Indicating Excessive Variability
UCL
A
B
C
C
B
A
LCL
Figure 9. Seven Out of Eight Points in Zone C or
Beyond Indicating Excessive Variability
SUMMARY
Motorola’s commitment to STATISTICAL PROCESS
CONTROLS has resulted in many significant improvements
to processes. Continued dedication to the SPC culture will
1–16
allow Motorola to reach beyond Six Sigma and zero defect
capability goals. SPC will further enhance the commitment to
TOTAL CUSTOMER SATISFACTION.
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Micromachined Accelerometer Reliability Testing Results
LIFE AND ENVIRONMENTAL TESTING RESULTS
STRESS TEST
High Temperature Bias
TA = 90°C, VDD = 5.0 V
t = 1000 hours, 12 minutes on, 8 seconds off
0/32
High Temperature/High Humidity Bias
TA = 85°C, RH = 85%,
VDD = 5.0 V, t = 2016
0/38
High Temperature Storage (Bake)
TA = 105°C, t = 1000 hours
0/35
Temperature Cycle
Freescale Semiconductor, Inc...
RESULTS
FAILED/PASS
CONDITIONS
Mechanical Shock
*40 to 105°C, Air to Air,
15 minutes at extremes,
v 5 minutes transfer, 1000 cycles
5 blows X1, X2, Y1, Y2, Z1, Z2
2.0 G’s, 0.5 mS, TA = *40°C, 25°C, 90°C
0/23
0/12
Vibration Variable Frequency
with Temperature Cycle
10 – 1 Khz @ 50 G’s max,
24 hours each axis,
X1, X2, Y1, Y2, Z1, Z2, TA = 40 to 90°C,
Dwell = 1 Hour, transfer = 65 minutes
0/12
Autoclave
TA = 121°C, RH = 100%
15 PSIG, t = 240 hours
0/71
Drop Test
10 Drops from 1.0 meters onto concrete,
any orientation
0/12
*
PARAMETERS MONITORED
LIMITS
INITIAL
PARAMETER
Offset
Self Test
Sensitivity
CONDITIONS
*
VDD = 5.0 V, 25,
*40 & 90°C
VDD = 5.0 V, 25,
*40 & 90°C
VDD = 5.0 V, 25,
40 & 90°C
Motorola Sensor Device Data
END POINTS
MIN
MAX
MIN
MAX
2.15 V
2.95 V
2.15 V
2.95V
20G
30 G
20 G
30 G
45 mV/G
55 mV/G
45 mV/G
55 mV/G
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Media Compatibility Disclaimer
Motorola has tested media tolerant sensor devices in
selected solutions or environments and test results are
based on particular conditions and procedures selected by
Motorola. Customers are advised that the results may vary
for actual services conditions. Customers are cautioned that
they are responsible to determine the media compatibility of
sensor devices in their applications and the foreseeable use
and misuses of their applications.
Sensor Media Compatibility: Issues and Answers
T. Maudie, D. J. Monk, D. Zehrbach, and D. Stanerson
Motorola Semiconductor Products Sector, Sensor Products Division
5005 E. McDowell Rd., Phoenix, AZ 85018
Freescale Semiconductor, Inc...
ABSTRACT
As sensors and actuators are embedded deeper into
electronic systems, the issue of media compatibility as well as
sensor and actuator performance and survivability becomes
increasingly critical. With a large number of definitions and
even more explanations of what media compatibility is, there
is a ground swell of confusion not only within the industry, but
among end users as well. The sensor industry must respond
to create a clear definition of what media compatibility is, then
strive to provide a comprehensive understanding and industry
wide agreement on what is involved in assessing media
tolerance and compatibility. Finally, the industry must create
a standard set of engineering parameters to design, evaluate,
test, and ultimately qualify sensor and actuators functioning in
various media conditions. This paper defines media
compatibility, identifies pertinent compatibility issues, and
recommends a path to industry standardization.
INTRODUCTION
Microelectromechanical System (MEMS) reliability in
various media is a subject that has not yet received much
attention in the literature yet [1–3], but does bring up many
potential issues. The effects of long term media exposure to
the silicon MEMS device and material still need answers [4].
Testing can result in predictable silicon or package related
failures, but due to the complexity of the mechanisms,
deleterious failures can be observed. The sensor may be
exposed to diverse media in markets such as automotive,
industrial, and medical. This media may include polar or
nonpolar organic liquids, acids, bases, or aqueous solutions.
Integrated circuits (ICs) have long been exposed to
temperature extremes, humid environments, and mechanical
tests to demonstrate or predict the reliability of the device for
the application. Unlike a typical IC, a sensor often must exist
in direct contact with a harsh environment. The lack of harsh
media simulation test standardization for these direct contact
situations necessitates development of methods and
hardware to perform reliability tests.
The applicability of media compatibility affects all sensors to
some degree, but perhaps none more dramatically than a
piezoresistive pressure sensor. In order to provide an
accurate, linear output with applied pressure, the media
should come in direct contact with the silicon die. Any barrier
provided between the die and the media, limits the device
performance. A typical piezoresistive diaphragm pressure
sensor manufactured using bulk micromachining techniques
is shown in Figure 1. A definition for a media compatible
pressure sensor will be proposed.
To ensure accurate media testing, the requirements and
methods need to be understood, as well as what constitutes
a failure. An understanding of the physics of failure can
significantly reduce the development cycle time and produce
a higher quality product [5,6]. The focus of the
physics–of–failure approach includes the failure mechanism,
accelerating environment, and failure mode. The requirement
for a typical pressure sensor application involves long term
exposure to a variety of media at an elevated temperature and
may include additional acceleration components such as
static or cyclic temperature and pressure.
DIAPHRAGM
DIFFUSED
STRAIN GAUGE
METALLIZATION
ÉÉÉ
SILICON
WAFER
ETCHED
CAVITY
DIE
RTV DIE BOND
WIRE
INTERCONNECT
LEAD
FRAME
EPOXY
CASE
This paper was presented at Sensors Expo, Anaheim, CA, and is
reprinted with permission, Sensors Magazine (174 Concord St.,
Peterborough, NH 03458) and Expocon Management Associates,
Inc. (P.O. Box 915, Fairfield, CT 06430).
1–18
Figure 1. Typical bulk micromachined silicon
piezoresistive pressure sensor device
and package configuration.
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The failure mechanisms that may affect a sensor or actuator
will be discussed along with the contributors and acceleration
means. Failure mechanisms of interest during media testing
of semiconductor MEMS devices are shown in Table 1. MEMS
applications may involve disposable applications such as a
blood pressure monitor whose lifetime is several days.
General attributes to consider during testing include: lifetime
expectations, cost target, quality level, size, form, and
functionality.
Table 1. Typical Failure Mechanisms for
Sensors and Actuators [6–10]
Failure Mechanism
Uniform Corrosion
environment and permeability of the environment. The
environment may consist of media or moisture with ionics,
organics, and/or aqueous solutions, extreme temperatures,
voltage, and stress.
Permeability is the product of diffusivity and solubility.
Contributors to permeability include materials (e.g. polymeric
structures), geometry, processing, and whether or not the
penetration is in the bulk or at an interface. The environment
can also accelerate permeation if a concentration gradient,
elevated temperature and/or pressure exist. An example of
material dependence of permeation is shown in Figure 2.
Organic materials such as silicone can permeate 50% of the
relative moisture from the exterior within minutes where
inorganic materials such as glass takes years for the same
process to occur.
Localized Corrosion
PERMEABILITY (g/cm–s–torr)
–1
10–6
10–8
10–10
10–12
10–14
10–16
Silicon Etching
Polymer Swelling or Dissolution
–2
Interfacial Permeability
LOG THICKNESS (m)
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Galvanic Corrosion
Adhesive Strength
Fatigue Crack Initiation
Fatigue Crack Propagation
Environment Assisted Cracking
EPOXIES
FLUORO–CARBONS
–3
GLASSES
–4
–5
Creep
METALS
Methods for performing media compatibility testing to
determine the potential for the various failure mechanisms will
be presented. Attributes of the testing need to be well
understood so that proper assessment of failure and lifetime
approximation can be made. The lifetime modeling is key for
determination of the ability of a sensor device to perform its
intended function. Reliability modeling and determination of
activation energies for the models will provide the customer
with an understanding of the device performance. The
definition of an electrical failure can range from catastrophic,
to exceeding a predetermined limit, to just a small shift. The
traditional pre to post electrical characterization (before and
after the test interval) can be enhanced by in situ monitoring.
In situ monitoring may expose a problem with a MEMS device
during testing that might have gone undetected once the
media or another environmental factor is removed. This is a
common occurrence for a failure mechanism, such as
swelling, that may result in a shift in the output voltage of the
sensor. Response variables during environmental testing can
include: electrical, visual, analytical, or physical characteristics
such as swelling or weight change.
DEFINITIONS & UNDERLYING CAUSES
The definition of a media compatible pressure sensor is as
follows:
The ability of a pressure sensor to perform its specified
electromechanical function over an intended lifetime in the
chemical, electrical, mechanical, and thermal environments
encountered in a customer’s application.
The key elements of the definition are perform, function,
lifetime, environment, and application. All of these elements
are critical to meet the media compatibility needs. The
underlying causes of poor media compatibility is the hostile
Motorola Sensor Device Data
SILICONES
–6
MIN
HR
DAY
MO YR
10
YR
100
YR
TIME FOR PACKAGE INTERIOR TO REACH
50% OF EXTERIOR HUMIDITY *
Figure 2. Permeation relationship for various materials.
* Richard K. Traeger, “Nonhermiticity of Polymeric Lid Sealants,
IEEE Transactions on Parts, Hybrids, and Packaging, Vol. PHP–13,
No. 2, June 1977.
Gasoline and aqueous alkaline solutions represent two
relatively diverse applications that are intended for use with a
micromachined pressure sensor. The typical automotive
temperature range is from –40° to 150°C. This not only makes
material selection more difficult but also complicates the
associated hardware to perform the media related testing [11].
A typical aqueous alkaline solution application would be found
in the appliance industry. This industry typically has a
narrower temperature extreme then the automotive market,
but the solutions and the level of ions provide a particular
challenge to MEMS device reliability.
Gasoline contains additives such as: antiknock,
anti–preignition agents, dyes, antioxidants, metal
deactivators, corrosion inhibitors, anti–icers, injector or
carburetor detergents, and intake valve deposit control
additives [12]. To develop a common test scheme for the
liquid, a mixture table was developed for material testing in
gasoline/methanol mixtures. The gasoline/methanol mixtures
developed were intended for accelerated material testing with
a gasoline surrogate of ASTM Fuel Reference “C” (50%
toluene and 50% iso–octane) [13]. Material testing is
performed with samples either immersed in the liquid or
exposed to the vapor over the liquid. The highly aromatic Fuel
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“C” is intended to swell polymeric materials. Contaminants in
actual gasoline can result in corrosion or material degradation,
so chloride ions or formic acid with distilled water are added
to create an aggressive fuel media. Gasoline can decompose
by a process called auto–oxidation that will form aggressive
substances that can dissolve polymers or corrode metal. Copper
is added as a trace metal to accelerate the formation of free
radicals from the hydroperoxides. Table 2 details the various
gasoline/methanol mixtures with additives recommended by
the task force from Chrysler, Ford, and General Motors.
Table 2. Fuel Testing Methods
Elastomer
Alcohol/Fuel Blends
Metal
CMO
CMO
CM15
CM15
CM30
CM30
CM50
CM50
CM85
CM85
CM85
Chloride ion
Distilled water
Formic Acid
Chloride ion
Sodium Chloride
Formic Acid
t–Butyl Hydroperoxide
t–Butyl Hydroperoxide
Aggressive Fuel, Add
Freescale Semiconductor, Inc...
Polymer
Auto Oxidized Fuels, Add
CM15
Cu+
Recommended gasoline/methanol mixtures for material testing. The recommended testing for metals should include immersion in the liquid as
well as exposure to the vapor. The coding for the alcohol/fuel blends, CMxx is: C for Fuel C; M for methanol; and xx indicating the percentage of
methanol in the mixture.
The general question for the appliance industry
compatibility issues is not whether the media will contain
ions (as it most assuredly will) but at what concentration.
Tap water with no alkali additives contains ions capable of
contributing to a corrosive reaction [14]. A typical
application of a pressure sensor in the appliance industry is
sensing the water level in a washing machine. The primary
ingredients of detergent used in a washing machine are:
surfactants, builders, whitening agents and enzymes [15].
The surfactants dissolve dirt and emulsify oil, grease and
dirt. They can be anionic or cationic. Cationic surfactants
are present in detergent–softener combinations. Builders
or alkaline water conditioning agents are added to the
detergent to soften the water, thus increasing the efficiency
of the surfactant. These builders maintain alkalinity that
results in improved cleaning. Alkaline solutions at
temperatures indicated by the appliance industry range can
etch bare silicon similar to the bulk micromachining
process. Thus bare silicon could be adversely affected by
exposure to these liquids [16].
FAILURE MECHANISMS
The failure mechanisms that can affect sensors and
actuators are similar to that for electronic devices. These
failure mechanisms provide a means of categorizing the
varIous effects caused by chemical, mechanical,
electrical, and thermal environments encountered. An
understanding of the potential failure mechanisms should
be determined before media testing begins. The typical
industry scenario has been to follow a set boiler plate of
tests and then determine reliability. This may have been
acceptable for typical electronic devices, but the
applications for sensors are more demanding of a
thorough understanding before testing begins. The
sensitivity of the device to its physical environment is
heightened for a pressure sensor. Any change in the
1–20
material properties results in a change of the sensor
performance. Failure mechanisms for pressure sensors in
harsh media application are listed below. The pressure
sensor allows a format for discussion, though the
mechanisms discussed are applicable in some degree to
all sensor and actuator devices.
Corrosion
Corrosion has been defined as any destructive result of
a chemical reaction between a metal or metal alloy and its
environment [17]. Several metal surfaces exist within a
pressure sensor package: metallic lines on the die,
trimmable resistors, bonding pads, wires, leadframes, etc.
Much of the die–level metal is protected by an overlying
inorganic passivation material (e.g., PECVD silicon
nitride);
however,
unless
some
package–level
encapsulant is used, bondpads, wires, and leadframes are
exposed to the harsh media and are potential corrosion
sites. Furthermore, an energized pressure sensor has a
voltage difference between these exposed metallic
surfaces, which compounds the corrosion problem.
Generally, corrosion problems are organized into the
following categories: uniform corrosion; galvanic
corrosion, and localized corrosion (including, crevice
corrosion, pitting corrosion, etc.) [17]. The factors that
contribute to corrosion are: the substrate (metallic)
material and its surface structure and composition; the
influence of a barrier coating, its processing conditions
and/or adhesion promotion; the cleanliness of the surface,
adhesion between a coating and the surface, solution
concentration,
solution
components
(especially
impurities and/or oxidizers); localized geometry and
applied potential. In addition, galvanic corrosion is
influenced by specific metal–to–metal connections.
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PIEZORESISTIVE
TRANSDUCER
DIAPHRAGM
SILICON DIE
UNIBODY PACKAGE
LEAD FRAME
DIE ATTACH
WIREBOND
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NITRIC
Figure 3. Examples of uniform corrosion of a gold leadframe in nitric acid at 5 Vdc and galvanic corrosion on an
unbiased device at the gold wire/aluminum bondpad interface in commercial detergent.
Part of figure 3 shows an example of what we have
described as electrolytic corrosion (i.e., corrosion of similar
metallic surfaces in an electrolytic solution caused by a
sufficient difference in potential between the two surfaces).
This appears to be uniform corrosion of the gold leadframe
surface. It should be noted that this type of failure is observed
even on ‘noble’ metals like gold. Applied potential is the driving
force for the reaction. All metals can corrode in this fashion
depending on the solution concentration (pH) and the applied
potential. Pourbaix diagrams describe these thermodynamic
relationships [18].
Figure 3 shows an example of galvanic corrosion. The
figure illustrates that corrosion can also occur because of
dissimilar metals that are connected electrically and are
immersed in an electrolytic solutions. A difference in the
corrosion potential between the two metals is the driving force
for the reaction. Localized corrosion examples are prevalent
as well. Often they may be the precursor to what appears on
a macro scale to be uniform or galvanic corrosion. In situ
monitoring of devices in electrolytic media will allow better
diagnosis of this failure mechanism. Typical ex situ or interval
reliability testing may not allow diagnosis of the root cause to
the failure, thus limiting the predictive power of any resulting
reliability models.
Silicon Etching
Figure 4 shows the result of an accelerated test of a
pressure sensor die to a high temperature detergent solution.
The detergent used was a major consumer brand and resulted
in dramatic etching of the silicon. Alkaline solutions that
undergo a hydrolysis reaction may result in etching of the
silicon similar to a bulk micromaching operation. This failure
mechanism can cause a permanent change in the sensitivity
of the device because the sensitivity is proportional to the
Motorola Sensor Device Data
inverse square of the silicon thickness. Moreover, it can lead
to loss in bond integrity between wafers (Fig. 4). Silicon
etching [19–20], like corrosion reactions, is a chemical
reaction, so the contributing factors include the silicon
material, its crystal orientation and its doping level, the
solution type, concentration and pH, and the applied potential.
Temperature, concentration (i.e., pH), and voltage all act to
accelerate this process. Figure 5 shows an example of
modeling results that illustrates two of these variables.
Figure 4. Photograph of silicon etching after
exposure to an aqueous detergent solution at
elevated temperature for an extended time. A frit layer,
horizontally in the middle, adheres to silicon on
either side. The amount of etching is evident by
referencing the glass frit edge on the far left.
These two silicon edges were aligned to the frit
edge when the die was sawn.
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Solvents
Contour Plot of Detergent Concentraion and
Temperature vs Etch Rate ( m m/hr)
ISOOCTANE
Polymers
PTFE
7.5
POLYSULFONE
POLYURETHANE
PMMA
PET
TOLUENE
10
ETHANOL
12.5 NYLON
120
110
METHANOL
15
POLY (ACRYLONITRILE)
TEMP (C)
100
17.5
90
20
80
Freescale Semiconductor, Inc...
22.5
WATER
70
δ = [cal/cm3]1/2
60
0
10
20
30
40
50
Figure 6. Typical values of solubility parameter
(δ [cal/cm3]1/2) for solvents and polymers.
ULTRA TIDE CONC (g/l)
Etch Rate
Prediction
from Model
<= 0.10
<= 0.40
<= 0.20
> 0.40
<= 0.30
Figure 5. Experimental results for the etching of (100)
silicon with approximately 5x10–5 cm–3 boron
doping density in a commercially available detergent
as a function of temperature and detergent
concentration (which is proportional to pH).
Polymer Swelling or Dissolution
Swelling or dissolution affects those polymers typically
employed to package the micromachined structure and
depending on the nature of the media, may have a degrading
effect on device performance. These two related phenomena
are caused by solvent diffusing into the material and
occupying free volume within the polymer. The solubility
parameter gives a quantitative measure of the potential for
swelling [21]: i.e., it provides a quantitative measure of “like
dissolves like” (Fig. 6). Both the polymer and the solution
contribute to this failure mechanism, while the media
(specifically, the solubility parameter), the temperature, and
the pressure can be used as acceleration factors.
Figure 7 shows a photograph of a device after exposure to
a harsh fuel containing corrosive water solution. This
corrosion and evidence of swelling of the gel demonstrates the
vital importance the package has on the reliability of the
pressure sensor device. Also, it has been observed that
corrosion occurs more readily following swelling of a
polymeric encapsulant.
INITIAL EDGE
OF GEL
GEL EDGE
AFTER EXPOSURE
TO GASOLINE
WITH ETHANOL
Figure 7. Photograph of a pressure sensor device
after extended exposure to harsh fuel containing
corrosive water, followed by exposure to a strong
acid. Evidence of the gel swelling during the test,
and corresponding shrinkage after removal from the
test media can be seen by the gel retracting away
from the sidewall of the package.
1–22
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Interfacial Permeability
Lead leakage is a specific example of interfacial
permeability. It is pressure leakage through the polymer
housing material/metallic leadframe material interface from
the inside of the pressure sensor package to the outside of the
pressure sensor package or vice versa [22]. In addition, other
material interfaces can result in leakage. We describe another
specific example of this in the next section. Lead leakage is
like polymer swelling in that it may allow another failure
mechanism, like corrosion, to occur more readily. It also
causes a systematic pressure measurement error. Figure 8
shows the result of lead leakage measurements as a function
of temperature cycling. The polymer housing material (and its
CTE as a function of temperature), the leadframe material
(and its CTE), surface preparation and contamination, the
polymer matrix composition, and polymer processing all
contribute to this effect. It is accelerated by media,
temperature cycling, and applied pressure.
2.0
EPOXY
PPS GRADE 1
1.5
LEAD LEAKAGE (cc/min)
Freescale Semiconductor, Inc...
PPS GRADE 2
PBT
LCP
1.0
0.5
0.0
0
200
400
600
800
1000
TEMPERATURE CYCLES
Figure 8. Pressure leakage measurements through the metallic leadframe/polymeric housing material interface on a
pressure sensor as a function of temperature cycles between –40 and 125°C.
Adhesive Strength
Packaging of the sensor relies on adhesive material to
maintain a seal but not impart stress on the piezoresistive
element. Polymeric materials are the primary adhesive
materials which can range from low modulus material such as
silicone to epoxy with a high modulus. An example of a typical
joint is shown in Figure 9. The joint has three possible failure
locations with the preferred break being cohesive.
Contributors to a break include whether the joint is in tension
or compression, residual stresses, the adhesive material,
surface preparation, and contamination. An adhesive failure
is accelerated by media contact, cyclic or static temperature,
and cyclic or static stress (e.g. pressure).
Strength Components
DIE TO MAT’L
ADHESIVE
STRENGTH
COHESIVE
STRENGTH
DIE TO EPOXY
ADHESIVE
STRENGTH
Figure 9. Failure locations for an adhesive bond of
dissimilar materials.
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Mechanical Failures
The occurrence of mechanical failures include components
of fatigue, environment assisted cracking, and creep.
Packaging materials, process, and residual stresses are all
contributors to mechanical failure. A summary of acceleration
stresses is shown in Table 3. Contact with harsh media is an
accelerating stress for all of the mechanical failure mechanisms.
PRESSURE SENSOR SOLUTIONS
The range of solutions for pressure sensors to media
compatibility is very diverse. Mechanical pressure sensors still
occupy a number of applications due to this media compatibility
concern. These devices typically operate on a variable
inductance method and are typically not as linear as a
piezoresistive element. Figure 10 shows a comparison
between a mechanical pressure sensor and a piezoresistive
element for a washing machine level sensing application. The
graph shows a nonlinear response for the mechanical sensor
and a corresponding straight line for the piezoresistive element.
A common method of obtaining media compatibility is to
place a barrier coating over the die and wire interconnection.
This organic encapsulant provides a physical barrier between
the harsh environment and the circuitry. The barrier coating
can range from silicone to parylene or other dense films that
are typically applied as a very thin layer. This technique offers
limited protection to some environments due to swelling
and/or dissolution of the encapsulant material when in contact
with media with a similar solubility. When a polymeric material
has a solubility parameter of the same value as the
corresponding media, swelling or dissolution will occur.
Stainless steel diaphragms backfilled with silicone oil
provide a rugged barrier to most media environments, but
generally are very costly and limit the sensitivity of the device.
The silicone oil is used to transmit the stress from the
diaphragm to the piezoresistive element. If a polymeric
material is used as the die attach, the silicone oil will permeate
out of the package. This concern requires a die attach that is
typically of higher modulus than a silicone and may not
adequately isolate the package stress from the die.
Table 3. Mechanical Failure Mechanisms
Acceleration Stresses
Fatigue crack initiation
Mechanical stress/strain range
Cyclic temperature range
Frequency
Media
Fatigue crack propagation
Mechanical stress range
Cyclic temperature range
Frequency
Media
Environment assisted cracking
Mechanical stress
Temperature
Media
Creep
Mechanical stress
Temperature
Media
175
1.8
1.6
165
1.4
1.2
160
1
155
0.8
150
0.6
0.4
145
0.2
PIEZORESISTIVE PRESSURE SENSOR OUTPUT (VOLTS)
2
170
MECHANICAL SENSOR OUTPUT (HERTZ)
Freescale Semiconductor, Inc...
Failure Mechanism
0
140
0
1
2
3
4
5
6
TIME (MINUTES)
WASHING
MACHINE
SENSOR
PIEZORESISTIVE
PRESSURE
SENSOR
Figure 10. Graphical comparison of the output from a mechanical pressure sensor compared to a piezoresistive
sensor during a washing machine fill cycle.
1–24
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MEDIA TEST METHODS
Figures 11 and 12 show a test apparatus specifically intended
for use with solvents and Figure 13 an apparatus for aqueous
solutions. This test system has resulted in a realistic test
environment that provides electrical bias, in situ measurements,
FLUORINATED
HYDROCARBON
LIQUID WITH
EXTERNAL
HEATER
consistent stoichiometry, and temperature control all within a
safe environment. The safety aspects of the testing were
obtained by creating an environment free of oxygen to eliminate
the possibility of a fire. Results from the testing have included
swelling of silicone materials, corrosion, and adhesive failures.
TO AUTOMATIC TEST SYSTEM
WITH VOLTAGE AND CURRENT
LINKING PROTECTION
THERMOCOUPLES
POROUS NITROGEN
PURGE LINES
ELECTRICAL
CONNECTIONS
CONDENSER COILS
LID
MODULAR TEST
PLATE WITH
O–RING SEAL
Freescale Semiconductor, Inc...
SENSORS
L
I
Q
U
I
D
V
A
P
O
R
TANK
1
FROM PUMP
LOADING CHAMBER
TANK
2
TO PUMP TO DRAIN
Figure 11. Graphical depiction of the sensor media tester used for liquid or vapor exposure of the device to the
harsh media to accelerate the failure mechanisms or demonstrate compatibility.
Figure 12. Photograph of the load chamber area of the Media Test System allowing for fuel or solvent testing at
temperature with in situ monitoring of the devices under test (DUT’s) output.
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Figure 13. Photograph of the aqueous alkaline solution test system and the data acquisition system
for in situ monitoring of the MEMS devices.
LIFETIME MODELING
Reliability techniques provide a means to analyze media
test results and equate the performance to a lifetime
[23–24]. The primary reliability techniques involve an
understanding of the failure rate, life distributions, and
acceleration modeling. The failure rate for a product’s
lifetime follows the bathtub curve. This curve, as shown in
Figure 14, has an early life period with a decreasing failure
rate. Manufacturing defects would be an example of
failures during this portion of the curve. The second portion
of the curve, often described as the useful life region has
a constant failure rate. The last section has an increasing
failure rate and is referred to as the wearout region. This
wearout region would include failure mechanisms such as
corrosion or fatigue.
Product Failure Rate
END OF LIFE
OR WEAR OUT
FAILURE RATE
INFANT MORTALITY
OR EARLY LIFE
FAILURE RATE
STEADY STATE
FAILURE RATE
Time
Figure 14. Bathtub curve showing various failure rate regions.
Lifetime distributions provide a theoretical model to
describe device lifetimes. Common lifetime distributions
include the exponential, Weibull, lognormal, and extreme
value. The exponential distribution models a lifetime with a
1–26
constant failure rate An example of the exponential
distribution is a glass which has an equal probability of failing
the moment after it is manufactured, or when its ten years old.
The Weibull and lognormal distribution are all right, or
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positively skewed distributions. A right skewed distribution will
be a good model for data in a histogram with an extended right
tail. The Weibull distribution is sometimes referred to as a
distribution of minima. An example of a Weibull distribution is
the strength to break a chain where the weakest link describes
the strength of the chain. The extreme value distribution is a
distribution of maxima. It is the least utilized of the four life
distributions.
For means of example, the Weibull distribution will be used.
The Weibull lifetime distribution has the form:
+1*e
b
(1)
.
The two parameters for the Weibull distribution are q and b.
Theta is the scale parameter, or characteristic life. It
represents the 63.2 percentile of the life distribution. Beta is
the shape parameter. In order to determine the parameters for
the Weibull distribution, testing must be performed produce
failure on the devices. The failure data can be used to
calculate the maximum likelihood estimates or determined
graphically. It has not always been customary to perform
reliability demonstration testing until failures occur. In regards
to media testing, this seems to be the only method to derive
lifetime estimates that reflect a true understanding of the
device capability.
AF
ƪ ǒ Ǔƫ ǒ Ǔ
+
e
Ea
k
1
T low
*T 1
high
•
RH high
RH low
n
(2)
,
100%
90%
PROBABILITY OF FAILURE, F (t)
Freescale Semiconductor, Inc...
F(t, θ, β)
ǒǓ
* qt
A media test typically needs to take results received in
weeks or months to predict lifetime in years. Acceleration
models are used to determine the relationship between the
accelerated test and the normal lifetime. Literature has
reported numerous models to equate testing to lifetime
including the Peck model for temperature and humidity [25].
The acceleration equation based on Peck’s model is where Ea
is 0.9eV and n is –3.0. The value K is Boltzmann’s constant
which is equal to 8.6171x10–5 eV/K. The relative humidity is
entered as a whole number, i.e. 85 for 85%. Using this sample
model, test results from humidity testing can be related to the
lifetime. The methods to equate test time to lifetime first
involves fitting the failure data to a lifetime distribution. For an
example, humidity data at 60°C, 90% relative humidity and
bias was tested to failure. The failure data fit a Weibull
distribution with a characteristic life of 40,000 hours. By
applying the acceleration factor equation shown above,
quantification of the lifetime in the use conditions can be
calculated. Figure 15 shows the cumulative failure distribution
for the test and use conditions for a 15 year lifetime. This
technique is key for media testing since the range of use
conditions is very broad. The consumer can determine the
attributes for the sensor to use for the application. The
attributes might include cost, performance, and possibility for
replacement.
80%
Test Condition
(60 _C, 90% RH)
70%
60%
50%
40%
30%
20%
(30 _C, 85% RH)
10%
(25 _C, 60% RH)
0%
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
TIME (YEARS)
Figure 15. Probability of failure versus time for humidity testing with bias on an integrated sensor device.
The failure distribution example shown typically
represents one failure mechanism. The failure mechanism
that typifies humidity testing is mobile ions. An elevated
test temperature, humidity and bias contributes to the
mobility of the ions and the ability to create a surface
charge. By lowering the temperature, humidity or
switching the bias, an improvement in the lifetime can be
obtained. If a device manufacturer would test to failure and
report the lifetimes, the customer could select the
appropriate product for their application. Following a
template of reliability tests that have not been verified and
Motorola Sensor Device Data
do not coincide with the applicable failure mechanism may
put the application at risk for surviving.
Humidity testing was used as an example above, but a
similar case could be made of other attributes involved
with media testing. Other attributes of the media test may
include the bias level and duty cycle, the pH or conductivity
of the solution, and any stress such as a pressure
differential. By modeling these attributes against the
various solutions, models for media compatibility can be
developed.
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INDUSTRY STANDARDIZATION
Why an industry standard? The increasing use of electronic
sensors in everyday life has designers wrestling with the
complexity of defining the compatibility of a sensor with the
media they are measuring. A designer may decide to solve the
question of media compatibility by choosing to isolate the
sensor from the media via a stainless steel diaphragm. While
this solution provides very good media isolation, it is not
without some drawbacks such as cost, size of packaging,
decreased sensitivity and long term drift. Without a recognized
standard for defining media compatibility, the designer is left
to a series of ad hoc test methods and conflicting
specifications.
An industry media compatibility standard will provide the
designer with a method of evaluating sensor performance.
The designer could match an application’s requirements, for
media compatibility, with the available sensor products thus
taking price and performance into account. This will enable the
designer to minimize the total cost of an application. A
standard will also enable suppliers to provide products
warranted to defined criteria. Once a standard is adopted, the
suppliers may rationalize their test efforts and pass the
savings on to their customers.
A standard should provide a designer with a simple,
coherent, complete definition of a media’s effects on a sensor.
The standard should included an accepted test methodology,
test equipment guidelines, life time model, acceleration
factors model, and a definition of failures. A proposed list of
criteria to include in a model are shown in table 4.
Freescale Semiconductor, Inc...
Table 4. Suggested Criteria for Media Compatibility
Media Contact — Front or Back
Supply Voltage
Solubility Parameter
Pressure Range
Supply Voltage Duty Cycle
Conductivity of Media
Temperature Range
Voltage Potential within Media
pH
Recipe of Media and Contaminants
Frequency Output is Measured
Lifetime Expectancy
Sensor to Media Interconnection
Relative Motion of Media (e.g., Flow)
These criteria must be included not only for the media, but
also for the contaminants in the media. An example is a
washing machine level sensor which must be compatible with
water vapor (the media) and detergent and chlorine (the
contaminant). To create a standard, a series of tests which
benchmark the criteria must be designed and performed. The
results would form the basis of the life time and acceleration
factor models.
There are several ways to create a standard, each of which
have their own associated pros and cons. Three possible
ways to create a standard are: an industry association
committee, a panel of industry representatives, or a de facto
standard set by one or more industry suppliers. To define a
standard for media compatibility may require more than one
of these methods. An industry leader may define a standard
form to which they deliver product. This may stimulate the
formation of a committee which defines a broader standard for
the industry. As this standard becomes more accepted by the
industry, the committee may work with an industry association
to “legitimize” the de facto standard. No matter how the
standard is formulated, receiving broad industry acceptance
will require meeting the customers’ needs.
1–28
CONCLUSION
Investigation of media compatibility for pressure sensors
has been presented from a physics–of–failure approach. We
have developed a set of internal standard test and reliability
lifetime analysis procedures to simulate our customers’
requirements. These activities have incorporated information
from several fields beyond sensors and/or electronics,
including: electrochemistry and corrosion, polymers, safety
and environmental, automotive and appliance industry
standards, and reliability. The next critical step to elevating the
awareness of this problem, in our opinion, is to develop an
industry–wide set of standards, driven by customer
applications, that include media testing experimental
procedures, reliability lifetime analysis, and media
compatibility reporting to allow easier customer interpretation
of results.
ACKNOWLEDGMENTS
Many individuals have contributed to the media
compatibility initiative and are deserving of an
acknowledgment. The individuals include Debi Beall, Gordon
Bitko, Jerry Cripe, Bob Gailey, Jim Kasarskis, John Keller,
Betty Leung, Jeanene Matkin, Mike Menchio, Adan Ramirez,
Chuck Reed, Laura Rivers, Scott Savage, Mahesh Shah,
Mario Velez, John Wertz, MEMS1, MKL, Reliability Lab,
Characterization Lab, and the Prototype Lab.
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REFERENCE
Freescale Semiconductor, Inc...
(1)
Theresa Maudie, Testing Requirements and Reliability
Issues Encountered with Micromachined Structures,
Proceedings of the Second International Symposium
on Microstructures and Microfabricated Systems, Eds.
D. Denton, P.J. Hesketh and H. Hughes, ECS, vol.
95–27 (1995) pp. 223–230.
(2) Arne Nakladal et al., Influences of Humidity and Moisture on the Long–Term Stability of Piezoresistive Pressure Sensors, Measurement, vol. 16 (1995) pp. 21–29.
(3) Marin Nese and Anders Hanneborg, Anodic Bonding
of Silicon to Silicon Wafers Coated with Aluminum,
Silicon Oxide, Polysilicon or Silicon Nitride, Sensors
and Actuators A, vol. 37–38 (1993) pp. 61–67.
(4) Janusz Bryzek, Micromachines on the March, IEEE
Spectrum, May 1994.
(5) J. M. Hu, Physics–of–Failure–Based Reliability Qualification of Automotive Electronics, Communications in
RMS, vol. 1, no. 2 (1994) pp. 21–33.
(6) Michael Pecht et.al., Quality Conformance and Qualification of Microelectronics Packages and Interconnects, John Wiley & Sons, Inc., 1994.
(7) William M. Alvino, Plastics for Electronics, McGraw–
Hill, 1995
(8) Eugene R. Hnatek, Integrated Circuit Quality and Reliability, Marcel Dekker, Inc., 1987.
(9) Charles A. Harper, Handbook of Plastics, Elastomers,
and Composites, McGraw–Hill, 1992.
(10) Richard W. Hertzberg, Deformation and Fracture
Mechanics of Engineering Materials, John Wiley &
Sons, Inc., 1983.
(11) Joseph M. Giachino, Automotive Sensors: Driving
Toward Optimized Vehicle Performance, 7th Int’l Conference on Solid State Sensor and Actuators, June
1993.
(12) Perry Poiss, What Additives do for Gasoline, Hydrocarbon Processing, Feb. 1973.
Motorola Sensor Device Data
(13) Gasoline/Methanol Mixtures for Material Testing, SAE
Cooperative Research Report CRP–001, Sep. 1990.
(14) Private communication to Andrew McNeil from City of
Phoenix, Water and Wastewater Department, Water
Quality Division, Jan. 1994.
(15) Laundry Detergents, Consumer Reports, Feb. 1991,
pp. 100–106.
(16) Silicon as a Mechanical Material, Kurt E. Petersen,
Proc. IEEE, vol. 70, no. 5, pp. 420–457, May 1982.
(17) Principles and Prevention of Corrosion, Denny A.
Jones, (Prentice Hall: Englewood Cliffs, NJ, 1992).
(18) Atlas of Electrochemical Equilibria in Aqueous Solutions, M. Pourbaix, (Pergamon Press: Oxford, England, 1966)
(19) Anisotropic Etching of Crystalline Silicon in Alkaline
Solutions, Part I. Orientation Dependence and Behavior of Passivation Layers, H. Seidel et al., J. Electrochem. Soc., vol. 137, no. 11 (1990) pp. 3612–3625.
(20) Anisotropic Etching of Crystalline Silicon in Alkaline
Solutions, Part II. Influence of Dopants, H. Seidel et
al., J. Electrochem. Soc., vol. 137, no. 11 (1990)
pp. 3612–3625.
(21) Principles of Polymer Systems, 2nd ed., F. Rodriguez,
(Hemisphere Publishing Corporation: Washington,
D.C., 1982.
(22) D. J. Monk, Pressure Leakage through Material Interfaces in Pressure Sensor Packages, Sensors in Electronic Packaging, Eds. Charles Ume and Chao
Pin–Yeh, MED–Vol. 3/EEP–Vol.14 (1995) pp. 87–93.
(23) Paul A. Tobias and David C. Trindade, Applied Reliability, Van Nostrand Reinhold, 1995.
(24) Wayne Nelson, Accelerated Testing, John Wiley &
Sons, Inc., 1990.
(25) O. Hallberg and D. S. Peck, “Recent Humidity Accelerations, A Base for Testing Standards,” Quality and
Reliability Engr. International, Vol. 7, pp 169–180,
1991.
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1–30
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Freescale Semiconductor, Inc...
Section Two
Acceleration
Sensor Products
Mini Selector Guide . . . . . . . . . . . . . . . . . . . . . . . . . 2–2
Accelerometer Overview:
Motorola’s series of acceleration sensors incorporate a
surface micromachined structure. The force of acceleration
moves the seismic mass, thereby changing the g–cell’s
capacitance. Coupled with the g–cell is a control chip to provide the accelerometer with signal amplification, signal
conditioning, low pass filter and temperature compensation.
With Zero–g offset, sensitivity and filter roll–off that is factory
set, the device requires only a few external passives. In fact,
this acceleration sensor device offers a calibrated self–test
feature that mechanically displaces the seismic mass with
the application of a digital self–test signal. The g–cell is
hermetically sealed at the die level, creating a particle–free
environment with features such as built in damping and
over–range stops to protect it from mechanical shock.
These acceleration sensors are rugged, highly accurate
and feature X, XY, and Z axis of sensitivity.
Motorola’s acceleration sensors are economical, accurate
and highly reproducible for the ideal sensing solution in automotive, industrial, commercial and consumer applications.
Device Numbering System . . . . . . . . . . . . . . . . . . 2–2
Sensor Applications . . . . . . . . . . . . . . . . . . . . . . . . . 2–3
Acceleration Sensor FAQ’s . . . . . . . . . . . . . . . . . . 2–4
Data Sheets
MMA1200D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2– 5
MMA1201P . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–12
MMA1220D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2– 18
MMA1250D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–24
MMA1260D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–30
MMA1270D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–36
MMA2201D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2– 42
MMA2202D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2– 48
MMA3201D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2– 55
Application Notes
AN1559
AN1611
AN1612
AN1632
AN1635
AN1640
AN1925
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2– 62
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–65
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–77
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2– 84
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2– 89
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–101
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2– 104
Case Outlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–107
Glossary of Terms . . . . . . . . . . . . . . . . . . . . . . . . . 2–109
Motorola Sensor Device Data
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Mini Selector Guide
Accelerometer Sensor
Acceleration
Range
(g)
Sensing
Axis
AC
Sensitivity
(mV/g)
VDD
Supply Voltage
(Typ) (V)
Zero g Output
(Typ) (V)
MMA1200D
±250g
Z axis
8.0
5.0
2.5
MMA1201P
±38g
Z axis
50
5.0
2.5
MMA1220D
±8g
Z axis
250
5.0
2.5
MMA1250D
±5g
Z axis
400
5.0
2.5
MMA1260D
±1.5g
Z axis
1200
5.0
2.5
MMA1270D
±2.5g
Z axis
750
5.0
2.5
MMA2200W
±38g
X axis
50
5.0
2.5
MMA2201D
±38g
X axis
50
5.0
2.5
MMA2202D
±50g
X axis
40
5.0
2.5
MMA3201D
±38g
X–Y axis
50
5.0
2.5
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Device
Device Numbering System for Accelerometers
P M M A XXXX D
PROTOTYPE
PACKAGE
D
SOIC (Surface Mount)
P
16 Pin Dip
W Wingback
MOTOROLA
MICROMACHINED
ACCELEROMETER
AXIS OF SENSITIVITY
1000 SERIES — Z AXIS
2000 SERIES — X AXIS
3000 SERIES — X–Y AXIS
2–2
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Sensor Applications
AUTOMOTIVE APPLICATIONS
•
•
•
•
•
•
•
•
Airbags
Rollover detection
Fuel shut–off valve
Crash detection
Suspension control
Vehicle dynamic control
Braking systems
Occupant safety
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HEALTHCARE / FITNESS APPLICATIONS
•
•
•
•
•
•
•
Physical therapy
Rehabilitation equipment
Range of body motion measurement
Pedometers
Ergonomics tools
Sports medicine equipment
Sports diagnostic systems
Motorola Sensor Device Data
INDUSTRIAL / CONSUMER
APPLICATIONS
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Game pads
Vibration monitoring
Computer hard drive protection
Appliance balance and vibration controls
Seismic detection
Seismic switches
Security systems
Security enhancement equipment
Mouse control for Handheld devices
Cell phone menu selection scrolling
Virtual reality input devices
Dead reckoning in navigation systems
Bearing wear monitoring
Inclinometers
Robotics
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Acceleration Sensor FAQ’s
We have discovered that many of our customers have
similar questions about certain aspects of our accelerometer’s technology and operation. Here are the most frequently
asked questions and answers that have been explained in
relatively non–technical terms.
Q. What is the g–cell?
A. The g–cell is the acceleration transducer within the
accelerometer device. It is hermetically sealed at the
wafer level to ensure a contaminant free environment,
resulting in superior reliability performance.
Freescale Semiconductor, Inc...
Q. What does the output typically interface with?
A. The accelerometer device is designed to interface with an
analog to digital converter available on most microcontrollers. The output has a 2.5 V DC offset, therefore positive
and negative acceleration is measurable. For unique
customer applications, the output voltage can be scaled
and shifted to meet requirements using external circuitry.
Q. What is the resonant frequency of the g–cell?
A. The resonant frequency of the g–cell is much higher than
the cut–off frequency of the internal filter. Therefore, the
resonant frequency of the g–cell does not play a role in
the accelerometer response.
2–4
Q. What is ratiometricity?
A. Ratiometricity simply means that the output offset
voltage and sensitivity scales linearly with applied supply
voltage. That is, as you increase supply voltage the
sensitivity and offset increase linearly; as supply voltage
decreases, offset and sensitivity decrease linearly. This
is a key feature when interfacing to a microcontroller or
an A/D converter. Ratiometricity allows for system level
cancellation of supply induced errors in the analog to
digital conversion process. Refer to the Special Features
section under the Principle of Operation for more
information.
Q. Is the accelerometer device sensitive to electro
static discharge (ESD)?
A. Yes. The accelerometer should be handled like other
CMOS technology devices.
Q. Can the g–cell part “latch’’?
A. No, overrange stops have been designed into the g–cell to
prevent latching. (Latching is when the middle plate of
the g–cell sticks to the top or bottom plate.)
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MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
Surface Mount
Micromachined Accelerometer
MMA1200D
The MMA series of silicon capacitive, micromachined accelerometers
features signal conditioning, a 4–pole low pass filter and temperature
compensation. Zero–g offset full scale span and filter cut–off are factory set and
require no external devices. A full system self–test capability verifies system
functionality.
MMA1200D: Z AXIS SENSITIVITY
MICROMACHINED
ACCELEROMETER
± 250g
Features
• Integral Signal Conditioning
• Linear Output
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• Ratiometric Performance
• 4th Order Bessel Filter Preserves Pulse Shape Integrity
• Calibrated Self–test
16
• Low Voltage Detect, Clock Monitor, and EPROM Parity Check Status
• Transducer Hermetically Sealed at Wafer Level for Superior Reliability
9
• Robust Design, High Shocks Survivability
1
8
Typical Applications
• Vibration Monitoring and Recording
16 LEAD SOIC
CASE 475
• Impact Monitoring
Pin Assignment
N/C
N/C
N/C
ST
VOUT
STATUS
VSS
VDD
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
N/C
9
N/C
N/C
N/C
N/C
N/C
N/C
N/C
SIMPLIFIED ACCELEROMETER FUNCTIONAL BLOCK DIAGRAM
VDD
G–CELL
SENSOR
ST
SELF–TEST
INTEGRATOR
GAIN
CONTROL LOGIC &
EPROM TRIM CIRCUITS
FILTER
OSCILLATOR
TEMP
COMP
VOUT
CLOCK GEN.
VSS
STATUS
Figure 1. Simplified Accelerometer Functional Block Diagram
REV 0
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MMA1200D
MAXIMUM RATINGS (Maximum ratings are the limits to which the device can be exposed without causing permanent damage.)
Symbol
Value
Unit
Powered Acceleration (all axes)
Rating
Gpd
500
g
Unpowered Acceleration (all axes)
Gupd
2000
g
Supply Voltage
VDD
–0.3 to +7.0
V
Ddrop
1.2
m
Tstg
– 40 to +105
°C
Drop Test(1)
Storage Temperature Range
NOTES:
1. Dropped onto concrete surface from any axis.
Freescale Semiconductor, Inc...
ELECTRO STATIC DISCHARGE (ESD)
WARNING: This device is sensitive to electrostatic
discharge.
Although the Motorola accelerometers contain internal
2kV ESD protection circuitry, extra precaution must be taken
by the user to protect the chip from ESD. A charge of over
2–6
2000 volts can accumulate on the human body or associated
test equipment. A charge of this magnitude can alter the performance or cause failure of the chip. When handling the
accelerometer, proper ESD precautions should be followed
to avoid exposing the device to discharges which may be
detrimental to its performance.
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MMA1200D
OPERATING CHARACTERISTICS
(Unless otherwise noted: –40°C
v TA v +85°C, 4.75 v VDD v 5.25, Acceleration = 0g, Loaded output(1))
Characteristic
Symbol
Min
Typ
Max
Unit
VDD
IDD
TA
gFS
4.75
3.0
40
—
5.00
—
—
47
5.25
6.0
+85
—
V
mA
°C
g
VOFF
VOFF,V
S
SV
f –3dB
NLOUT
2.2
0.44 VDD
7.5
1.47
360
2.0
2.5
0.50 VDD
8.0
1.6
400
—
2.8
0.56 VDD
8.5
1.72
440
2.0
V
V
mV/g
mV/g/V
Hz
% FSO
nRMS
nPSD
nCLK
—
—
—
—
110
2.0
2.8
—
—
mVrms
µV/(Hz1/2)
mVpk
Self–Test
Output Response
Input Low
Input High
Input Loading(7)
Response Time(8)
gST
VIL
VIH
IIN
tST
55
VSS
0.7 x VDD
30
—
95
0.3 x VDD
VDD
260
10
g
V
V
µA
ms
Status(12)(13)
Output Low (Iload = 100 µA)
Output High (Iload = 100 µA)
VOL
VOH
—
VDD .8
—
—
0.4
—
V
V
Minimum Supply Voltage (LVD Trip)
VLVD
2.7
3.25
4.0
V
fmin
50
—
260
kHz
Output Stage Performance
Electrical Saturation Recovery Time(9)
Full Scale Output Range (IOUT = 200 µA)
Capacitive Load Drive(10)
Output Impedance
tDELAY
VFSO
CL
ZO
—
VSST
—
—
0.2
—
—
300
—
VDD 0.3
100
—
ms
V
pF
Ω
Mechanical Characteristics
Transverse Sensitivity(11)
Package Resonance
VXZ,YZ
fPKG
—
—
—
10
5.0
—
% FSO
kHz
Operating Range(2)
Supply Voltage(3)
Supply Current
Operating Temperature Range
Acceleration Range
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Output Signal
Zero g (VDD = 5.0 V)(4)
Zero g
Sensitivity (TA = 25°C, VDD = 5.0 V)(5)
Sensitivity
Bandwidth Response
Nonlinearity
Noise
RMS (.01–1 kHz)
Power Spectral Density
Clock Noise (without RC load on output)(6)
Clock Monitor Fail Detection Frequency
*
*
*
77
—
—
100
2.0
*
*
*
NOTES:
1. For a loaded output the measurements are observed after an RC filter consisting of a 1 kΩ resistor and a 0.01 µF capacitor to ground.
2. These limits define the range of operation for which the part will meet specification.
3. Within the supply range of 4.75 and 5.25 volts, the device operates as a fully calibrated linear accelerometer. Beyond these supply limits
the device may operate as a linear device but is not guaranteed to be in calibration.
4. The device can measure both + and acceleration. With no input acceleration the output is at midsupply. For positive acceleration the output
will increase above VDD/2 and for negative acceleration the output will decrease below VDD/2.
5. The device is calibrated at 35g.
6. At clock frequency
70 kHz.
7. The digital input pin has an internal pull–down current source to prevent inadvertent self test initiation due to external board level leakages.
8. Time for the output to reach 90% of its final value after a self–test is initiated.
9. Time for amplifiers to recover after an acceleration signal causing them to saturate.
10. Preserves phase margin (60°) to guarantee output amplifier stability.
11. A measure of the device’s ability to reject an acceleration applied 90° from the true axis of sensitivity.
12. The Status pin output is not valid following power–up until at least one rising edge has been applied to the self–test pin. The Status pin is
high whenever the self–test input is high.
13. The Status pin output latches high if a Low Voltage Detection or Clock Frequency failure occurs, or the EPROM parity changes to odd. The
Status pin can be reset by a rising edge on self–test, unless a fault condition continues to exist.
*
^
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MMA1200D
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PRINCIPLE OF OPERATION
The Motorola accelerometer is a surface–micromachined
integrated–circuit accelerometer.
The device consists of a surface micromachined capacitive sensing cell (g–cell) and a CMOS signal conditioning
ASIC contained in a single integrated circuit package. The
sensing element is sealed hermetically at the wafer level
using a bulk micromachined “cap’’ wafer.
The g–cell is a mechanical structure formed from semiconductor materials (polysilicon) using semiconductor processes (masking and etching). It can be modeled as two
stationary plates with a moveable plate in–between. The
center plate can be deflected from its rest position by subjecting the system to an acceleration (Figure 2).
When the center plate deflects, the distance from it to one
fixed plate will increase by the same amount that the distance to the other plate decreases. The change in distance is
a measure of acceleration.
The g–cell plates form two back–to–back capacitors
(Figure 3). As the center plate moves with acceleration, the
distance between the plates changes and each capacitor’s
value will change, (C = Aε/D). Where A is the area of the
plate, ε is the dielectric constant, and D is the distance
between the plates.
The CMOS ASIC uses switched capacitor techniques to
measure the g–cell capacitors and extract the acceleration
data from the difference between the two capacitors. The
ASIC also signal conditions and filters (switched capacitor)
the signal, providing a high level output voltage that is ratiometric and proportional to acceleration.
Acceleration
Figure 2. Transducer
Physical Model
Self–Test
The sensor provides a self–test feature that allows the
verification of the mechanical and electrical integrity of the
accelerometer at any time before or after installation. This
feature is critical in applications such as automotive airbag
systems where system integrity must be ensured over the life
of the vehicle. A fourth “plate’’ is used in the g–cell as a self–
test plate. When the user applies a logic high input to the
self–test pin, a calibrated potential is applied across the
self–test plate and the moveable plate. The resulting electrostatic force (Fe = 1/2 AV2/d2) causes the center plate to
deflect. The resultant deflection is measured by the accelerometer’s control ASIC and a proportional output voltage
results. This procedure assures that both the mechanical
(g–cell) and electronic sections of the accelerometer are
functioning.
Ratiometricity
Ratiometricity simply means that the output offset voltage
and sensitivity will scale linearly with applied supply voltage.
That is, as you increase supply voltage the sensitivity and
offset increase linearly; as supply voltage decreases, offset
and sensitivity decrease linearly. This is a key feature when
interfacing to a microcontroller or an A/D converter because
it provides system level cancellation of supply induced errors
in the analog to digital conversion process.
Status
Motorola accelerometers include fault detection circuitry
and a fault latch. The Status pin is an output from the fault
latch, OR’d with self–test, and is set high whenever one (or
more) of the following events occur:
• Supply voltage falls below the Low Voltage Detect (LVD)
voltage threshold
• Clock oscillator falls below the clock monitor minimum
frequency
• Parity of the EPROM bits becomes odd in number.
The fault latch can be reset by a rising edge on the self–
test input pin, unless one (or more) of the fault conditions
continues to exist.
BASIC CONNECTIONS
Figure 3. Equivalent
Circuit Model
Pinout Description
SPECIAL FEATURES
N/C
Filtering
The Motorola accelerometers contain an onboard 4–pole
switched capacitor filter. A Bessel implementation is used
because it provides a maximally flat delay response (linear
phase) thus preserving pulse shape integrity. Because the filter is realized using switched capacitor techniques, there is
no requirement for external passive components (resistors
and capacitors) to set the cut–off frequency.
N/C
N/C
2–8
ST
VOUT
STATUS
VSS
VDD
1
2
3
4
5
6
7
8
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16
15
14
13
12
11
10
N/C
9
N/C
N/C
N/C
N/C
N/C
N/C
N/C
Motorola Sensor Device Data
PCB Layout
Pin Name
1 thru 3
—
Redundant VSS. Leave unconnected.
4
ST
Logic input pin used to initiate
self–test.
5
VOUT
STATUS
7
8
VSS
VDD
9 thru 13
Trim pins
14 thru 16
—
VDD
Description
Output voltage of the accelerometer.
Logic output pin to indicate fault.
The power supply ground.
P1
ST
VOUT
VSS
VDD
P0
A/D IN
R
1 kΩ
C 0.01 µF
C 0.1 µF
VRH
The power supply input.
C
Used for factory trim. Leave
unconnected.
No internal connection. Leave
unconnected.
4 ST
8 VDD
VOUT
C1
0.1 µF
7 VSS
5
C 0.1 µF
VDD
0.1 µF
POWER SUPPLY
STATUS
R1
1 kΩ
OUTPUT
SIGNAL
C2
0.01 µF
Figure 4. SOIC Accelerometer with Recommended
Connection Diagram
Motorola Sensor Device Data
VSS
Figure 5. Recommend PCB Layout for Interfacing
Accelerometer to Microcontroller
6
MMA1200D
LOGIC
INPUT
STATUS
ACCELEROMETER
Pin No.
6
MMA1200D
MICROCONTROLLER
Freescale Semiconductor, Inc...
Freescale Semiconductor, Inc.
NOTES:
• Use a 0.1 µF capacitor on VDD to decouple the power
source.
• Physical coupling distance of the accelerometer to the
microcontroller should be minimal.
• Place a ground plane beneath the accelerometer to reduce
noise, the ground plane should be attached to all of the
open ended terminals shown in Figure 4.
• Use an RC filter of 1 kΩ and 0.01 µF on the output of the
accelerometer to minimize clock noise (from the switched
capacitor filter circuit).
• PCB layout of power and ground should not couple power
supply noise.
• Accelerometer and microcontroller should not be a high
current path.
• A/D sampling rate and any external power supply switching
frequency should be selected such that they do not interfere with the internal accelerometer sampling frequency.
This will prevent aliasing errors.
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2–9
Freescale Semiconductor, Inc.
MMA1200D
Positive Acceleration Sensing Direction
–Z
Freescale Semiconductor, Inc...
–Z
+Z
+Z
Side View
Side View
Direction of Earth’s gravity field.*
Side View
* When positioned as shown, the Earth’s gravity will result in a positive 1g output
ORDERING INFORMATION
Device
MMA1200D
Temperature Range
*40 to +85°C
Case No.
Package
Case 475–01
SOIC–16
MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS
Surface mount board layout is a critical portion of the total
design. The footprint for the surface mount packages must
be the correct size to ensure proper solder connection interface between the board and the package. With the correct
2–10
footprint, the packages will self–align when subjected to a
solder reflow process. It is always recommended to design
boards with a solder mask layer to avoid bridging and shorting between solder pads.
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
0.380 in.
9.65 mm
MMA1200D
0.050 in.
1.27 mm
Freescale Semiconductor, Inc...
0.024 in.
0.610 mm
0.080 in.
2.03 mm
Figure 6. Footprint SOIC–16 (Case 475–01)
Motorola Sensor Device Data
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2–11
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
MMA1201P
MMA2200W
Micromachined Accelerometer
The MMA series of silicon capacitive, micromachined accelerometers
features signal conditioning, a 4–pole low pass filter and temperature
compensation. Zero–g offset full scale span and filter cut–off are factory set and
require no external devices. A full system self–test capability verifies system
functionality.
Features
• Integral Signal Conditioning
Freescale Semiconductor, Inc...
• Linear Output
MMA1201P: Z AXIS SENSITIVITY
MMA2200W: X AXIS SENSITIVITY
MICROMACHINED
ACCELEROMETER
± 40g
• Ratiometric Performance
• 4th Order Bessel Filter Preserves Pulse Shape Integrity
• Calibrated Self–test
• Low Voltage Detect, Clock Monitor, and EPROM Parity Check Status
16
15
14
13
12
11
10
9
• Transducer Hermetically Sealed at Wafer Level for Superior Reliability
• Robust Design, High Shocks Survivability
• Two Packaging Options Available:
1) Plastic DIP for Z Axis Sensing (MMA1201P)
2) Wingback for X Axis Sensing (MMA2200W)
1
2
3
4
5
6
7
8
DIP PACKAGE
CASE 648C
MMA1201P
Typical Applications
• Vibration Monitoring and Recording
• Appliance Control
• Mechanical Bearing Monitoring
• Computer Hard Drive Protection
12
• Computer Mouse and Joysticks
• Virtual Reality Input Devices
3
4
5
6
WB PACKAGE
CASE 456
MMA2200W
• Sports Diagnostic Devices and Systems
SIMPLIFIED ACCELEROMETER FUNCTIONAL BLOCK DIAGRAM
VDD
G–CELL
SENSOR
VST
SELF–TEST
INTEGRATOR
GAIN
CONTROL LOGIC &
EPROM TRIM CIRCUITS
FILTER
OSCILLATOR
TEMP
COMP
VOUT
CLOCK GEN.
VSS
STATUS
Figure 1. Simplified Accelerometer Functional Block Diagram
REV 0
2–12
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Motorola Sensor Device Data
Freescale Semiconductor, Inc. MMA1201P MMA2200W
MAXIMUM RATINGS (Maximum ratings are the limits to which the device can be exposed without causing permanent damage.)
Symbol
Value
Unit
Powered Acceleration (all axes)
Rating
Gpd
500
g
Unpowered Acceleration (all axes)
Gupd
2000
g
Supply Voltage
VDD
–0.3 to +7.0
V
Ddrop
1.2
m
Tstg
– 40 to +105
°C
Drop Test(1)
Storage Temperature Range
NOTES:
1. Dropped onto concrete surface from any axis.
Freescale Semiconductor, Inc...
ELECTRO STATIC DISCHARGE (ESD)
WARNING: This device is sensitive to electrostatic
discharge.
Although the Motorola accelerometers contain internal
2kV ESD protection circuitry, extra precaution must be taken
by the user to protect the chip from ESD. A charge of over
Motorola Sensor Device Data
2000 volts can accumulate on the human body or associated
test equipment. A charge of this magnitude can alter the performance or cause failure of the chip. When handling the
accelerometer, proper ESD precautions should be followed
to avoid exposing the device to discharges which may be
detrimental to its performance.
www.motorola.com/semiconductors
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Information On This Product,
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2–13
Freescale Semiconductor, Inc.
MMA1201P MMA2200W
OPERATING CHARACTERISTICS
(Unless otherwise noted: –40°C
v TA v +85°C, 4.75 v VDD v 5.25, Acceleration = 0g, Loaded output(1))
Characteristic
Symbol
Min
Typ
Max
Unit
VDD
IDD
TA
gFS
4.75
4.0
40
—
5.00
5.0
—
38
5.25
6.0
+85
—
V
mA
°C
g
VOFF
VOFF,V
S
SV
f –3dB
NLOUT
2.2
0.44 VDD
47.5
9.3
360
1.0
2.5
0.50 VDD
50
10
400
—
2.8
0.56 VDD
52.5
10.7
440
+1.0
V
V
mV/g
mV/g/V
Hz
% FSO
nRMS
nPSD
nCLK
—
—
—
—
110
2.0
3.5
—
—
mVrms
µV/(Hz1/2)
mVpk
Self–Test
Output Response
Input Low
Input High
Input Loading(7)
Response Time(8)
gST
VIL
VIH
IIN
tST
20
VSS
0.7 x VDD
30
—
30
0.3 x VDD
VDD
300
10
g
V
V
µA
ms
Status(12)(13)
Output Low (Iload = 100 µA)
Output High (Iload = 100 µA)
VOL
VOH
—
VDD .8
—
—
0.4
—
V
V
Minimum Supply Voltage (LVD Trip)
VLVD
2.7
3.25
4.0
V
fmin
50
—
260
kHz
Output Stage Performance
Electrical Saturation Recovery Time(9)
Full Scale Output Range (IOUT = 200 µA)
Capacitive Load Drive(10)
Output Impedance
tDELAY
VFSO
CL
ZO
—
0.3
—
—
0.2
—
—
300
—
VDD 0.3
100
—
ms
V
pF
Ω
Mechanical Characteristics
Transverse Sensitivity(11)
Package Resonance
VZX,YX
fPKG
—
—
—
10
5.0
—
% FSO
kHz
Operating Range(2)
Supply Voltage(3)
Supply Current
Operating Temperature Range
Acceleration Range
Freescale Semiconductor, Inc...
Output Signal
Zero g (VDD = 5.0 V)(4)
Zero g
Sensitivity (TA = 25°C, VDD = 5.0 V)(5)
Sensitivity (VDD = 5.0 V)
Bandwidth Response
Nonlinearity
Noise
RMS (.01–1 kHz)
Power Spectral Density
Clock Noise (without RC load on output)(6)
Clock Monitor Fail Detection Frequency
*
*
*
—
—
—
110
2.0
*
*
*
*
NOTES:
1. For a loaded output the measurements are observed after an RC filter consisting of a 1 kΩ resistor and a 0.01 µF capacitor to ground.
2. These limits define the range of operation for which the part will meet specification.
3. Within the supply range of 4.75 and 5.25 volts, the device operates as a fully calibrated linear accelerometer. Beyond these supply limits
the device may operate as a linear device but is not guaranteed to be in calibration.
4. The device can measure both + and acceleration. With no input acceleration the output is at midsupply. For positive acceleration the output
will increase above VDD/2 and for negative acceleration the output will decrease below VDD/2.
5. The device is calibrated at 20g.
6. At clock frequency
70 kHz.
7. The digital input pin has an internal pull–down current source to prevent inadvertent self test initiation due to external board level leakages.
8. Time for the output to reach 90% of its final value after a self–test is initiated.
9. Time for amplifiers to recover after an acceleration signal causing them to saturate.
10. Preserves phase margin (60°) to guarantee output amplifier stability.
11. A measure of the device’s ability to reject an acceleration applied 90° from the true axis of sensitivity.
12. The Status pin output is not valid following power–up until at least one rising edge has been applied to the self–test pin. The Status pin is
high whenever the self–test input is high.
13. The Status pin output latches high if a Low Voltage Detection or Clock Frequency failure occurs, or the EPROM parity changes to odd. The
Status pin can be reset by a rising edge on self–test, unless a fault condition continues to exist.
*
^
2–14
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Motorola Sensor Device Data
Freescale Semiconductor, Inc. MMA1201P MMA2200W
Freescale Semiconductor, Inc...
PRINCIPLE OF OPERATION
The Motorola accelerometer is a surface–micromachined
integrated–circuit accelerometer.
The device consists of a surface micromachined capacitive sensing cell (g–cell) and a CMOS signal conditioning
ASIC contained in a single integrated circuit package. The
sensing element is sealed hermetically at the wafer level
using a bulk micromachined “cap’’ wafer.
The g–cell is a mechanical structure formed from semiconductor materials (polysilicon) using semiconductor processes (masking and etching). It can be modeled as two
stationary plates with a moveable plate in–between. The
center plate can be deflected from its rest position by subjecting the system to an acceleration (Figure 2).
When the center plate deflects, the distance from it to one
fixed plate will increase by the same amount that the distance to the other plate decreases. The change in distance is
a measure of acceleration.
The g–cell plates form two back–to–back capacitors
(Figure 3). As the center plate moves with acceleration, the
distance between the plates changes and each capacitor’s
value will change, (C = Aε/D). Where A is the area of the
plate, ε is the dielectric constant, and D is the distance
between the plates.
The CMOS ASIC uses switched capacitor techniques to
measure the g–cell capacitors and extract the acceleration
data from the difference between the two capacitors. The
ASIC also signal conditions and filters (switched capacitor)
the signal, providing a high level output voltage that is ratiometric and proportional to acceleration.
Acceleration
systems where system integrity must be ensured over the life
of the vehicle. A fourth “plate’’ is used in the g–cell as a self–
test plate. When the user applies a logic high input to the
self–test pin, a calibrated potential is applied across the
self–test plate and the moveable plate. The resulting electrostatic force (Fe = 1/2 AV2/d2) causes the center plate to
deflect. The resultant deflection is measured by the accelerometer’s control ASIC and a proportional output voltage
results. This procedure assures that both the mechanical
(g–cell) and electronic sections of the accelerometer are
functioning.
Ratiometricity
Ratiometricity simply means that the output offset voltage
and sensitivity will scale linearly with applied supply voltage.
That is, as you increase supply voltage the sensitivity and
offset increase linearly; as supply voltage decreases, offset
and sensitivity decrease linearly. This is a key feature when
interfacing to a microcontroller or an A/D converter because
it provides system level cancellation of supply induced errors
in the analog to digital conversion process.
Status
Motorola accelerometers include fault detection circuitry
and a fault latch. The Status pin is an output from the fault
latch, OR’d with self–test, and is set high whenever one (or
more) of the following events occur:
• Supply voltage falls below the Low Voltage Detect (LVD)
voltage threshold
• Clock oscillator falls below the clock monitor minimum
frequency
• Parity of the EPROM bits becomes odd in number.
The fault latch can be reset by a rising edge on the self–
test input pin, unless one (or more) of the fault conditions
continues to exist.
BASIC CONNECTIONS
Pinout Description for the Wingback Package
Figure 2. Transducer
Physical Model
Figure 3. Equivalent
Circuit Model
12
SPECIAL FEATURES
Filtering
The Motorola accelerometers contain an onboard 4–pole
switched capacitor filter. A Bessel implementation is used
because it provides a maximally flat delay response (linear
phase) thus preserving pulse shape integrity. Because the filter is realized using switched capacitor techniques, there is
no requirement for external passive components (resistors
and capacitors) to set the cut–off frequency.
Self–Test
The sensor provides a self–test feature that allows the
verification of the mechanical and electrical integrity of the
accelerometer at any time before or after installation. This
feature is critical in applications such as automotive airbag
Motorola Sensor Device Data
3
4
5
6
Pin No.
Pin Name
Description
1
—
Leave unconnected or connect to signal ground
2
ST
Logic input pin to initiate self test
3
VOUT
Output voltage
4
Status
Logic output pin to indicate fault
5
VSS
Signal ground
6
VDD
Supply voltage (5 V)
—
Wings
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Support pins, internally connected to
lead frame. Tie to VSS.
2–15
Freescale Semiconductor, Inc.
MMA1201P MMA2200W
4
MMA2200W
VDD
LOGIC
INPUT
2 ST
6 VDD
VOUT
C1
0.1 µF
3
STATUS
R1
1 kΩ
OUTPUT
SIGNAL
C2
0.01 µF
5 VSS
Figure 4. Wingback Accelerometer with
Recommended Connection Diagram
VDD
6
MMA1201P
LOGIC
INPUT
4 ST
8 VDD
VOUT
C1
0.1 µF
5
STATUS
R1
1 kΩ
OUTPUT
SIGNAL
C2
0.01 µF
7 VSS
Figure 5. DIP Accelerometer with Recommended
Connection Diagram
PCB Layout
N/C
1
16
N/C
N/C
2
15
N/C
N/C
3
14
N/C
ST
4
13
N/C
VOUT
5
12
N/C
STATUS
6
11
N/C
VSS
7
10
N/C
VDD
8
9
N/C
ST
VOUT
VSS
VDD
P0
A/D IN
R
1 kΩ
C 0.01 µF
C 0.1 µF
VRH
C
VSS
C 0.1 µF
VDD
0.1 µF
POWER SUPPLY
Figure 6. Recommend PCB Layout for Interfacing
Accelerometer to Microcontroller
Pin No.
Pin Name
Description
1
—
Leave unconnected or connect to
signal ground.
2 thru 3
—
No internal connection. Leave unconnected.
4
ST
Logic input pin to initiate self test.
5
VOUT
Output voltage
6
Status
Logic output pin to indicate fault.
7
VSS
Signal ground
8
VDD
Supply voltage (5 V)
9 thru 13
Trim Pins
14 thru 16
—
2–16
ACCELEROMETER
Pinout Description for the DIP Package
P1
MICROCONTROLLER
Freescale Semiconductor, Inc...
STATUS
Used for factory trim. Leave unconnected.
No internal connection. Leave unconnected.
NOTES:
• Use a 0.1 µF capacitor on VDD to decouple the power
source.
• Physical coupling distance of the accelerometer to the
microcontroller should be minimal.
• Place a ground plane beneath the accelerometer to reduce
noise, the ground plane should be attached to all of the
open ended terminals shown in Figure 4.
• Use an RC filter of 1 kΩ and 0.01 µF on the output of the
accelerometer to minimize clock noise (from the switched
capacitor filter circuit).
• PCB layout of power and ground should not couple power
supply noise.
• Accelerometer and microcontroller should not be a high
current path.
• A/D sampling rate and any external power supply switching
frequency should be selected such that they do not interfere with the internal accelerometer sampling frequency.
This will prevent aliasing errors.
For www.motorola.com/semiconductors
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Motorola Sensor Device Data
Freescale Semiconductor, Inc. MMA1201P MMA2200W
Positive Acceleration Sensing Direction
DIP PACKAGE
WINGBACK PACKAGE
12
16
9
1
8
7
Freescale Semiconductor, Inc...
1
6
*
*
* When positioned as shown, the Earth’s gravity will result in a positive 1g output
Drilling Patterns
WB PACKAGE DRILLING PATTERN
.000 .090 .190 .290 .390 .490 .590 .680
.090
∅ .049 2X
.047
∅ .033 6X
.031
Measurement in inches
ORDERING INFORMATION
Device
Temperature Range
Case No.
Package
MMA1201P
–40 to +85°C
Case 648C–04
Plastic DIP
MMA2200W
–40 to +85°C
Case 456–06
Plastic Wingback
Motorola Sensor Device Data
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Information On This Product,
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2–17
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
Low G
Micromachined Accelerometer
The MMA series of silicon capacitive, micromachined accelerometers
features signal conditioning, a 4–pole low pass filter and temperature
compensation. Zero–g offset full scale span and filter cut–off are factory set and
require no external devices. A full system self–test capability verifies system
functionality.
Features
• Integral Signal Conditioning
MMA1220D
MMA1220D: Z AXIS SENSITIVITY
MICROMACHINED
ACCELEROMETER
± 8g
Freescale Semiconductor, Inc...
• Linear Output
• Ratiometric Performance
• 4th Order Bessel Filter Preserves Pulse Shape Integrity
16
• Calibrated Self–test
9
• Low Voltage Detect, Clock Monitor, and EPROM Parity Check Status
1
• Transducer Hermetically Sealed at Wafer Level for Superior Reliability
8
• Robust Design, High Shock Survivability
16 LEAD SOIC
CASE 475
Typical Applications
• Vibration Monitoring and Recording
• Appliance Control
• Mechanical Bearing Monitoring
Pin Assignment
• Computer Hard Drive Protection
N/C
• Virtual Reality Input Devices
N/C
ST
• Sports Diagnostic Devices and Systems
ORDERING INFORMATION
Device
Temperature Range
MMA1220D
–40 to +85°C
Case No.
Package
Case 475–01
SOIC–16
16
15
14
13
12
11
10
1
2
3
4
5
6
7
8
N/C
• Computer Mouse and Joysticks
VOUT
STATUS
VSS
VDD
9
N/C
N/C
N/C
N/C
N/C
N/C
N/C
N/C
SIMPLIFIED ACCELEROMETER FUNCTIONAL BLOCK DIAGRAM
VDD
G–CELL
SENSOR
ST
SELF–TEST
INTEGRATOR
GAIN
CONTROL LOGIC &
EPROM TRIM CIRCUITS
FILTER
OSCILLATOR
TEMP
COMP
VOUT
CLOCK GEN.
VSS
STATUS
Figure 1. Simplified Accelerometer Functional Block Diagram
REV 0
2–18
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MMA1220D
MAXIMUM RATINGS (Maximum ratings are the limits to which the device can be exposed without causing permanent damage.)
Symbol
Value
Unit
Powered Acceleration (all axes)
Rating
Gpd
1500
g
Unpowered Acceleration (all axes)
Gupd
2000
g
Supply Voltage
VDD
–0.3 to +7.0
V
Ddrop
1.2
m
Tstg
– 40 to +105
°C
Drop Test(1)
Storage Temperature Range
NOTES:
1. Dropped onto concrete surface from any axis.
Freescale Semiconductor, Inc...
ELECTRO STATIC DISCHARGE (ESD)
WARNING: This device is sensitive to electrostatic
discharge.
Although the Motorola accelerometers contain internal
2kV ESD protection circuitry, extra precaution must be taken
by the user to protect the chip from ESD. A charge of over
Motorola Sensor Device Data
2000 volts can accumulate on the human body or associated
test equipment. A charge of this magnitude can alter the performance or cause failure of the chip. When handling the
accelerometer, proper ESD precautions should be followed
to avoid exposing the device to discharges which may be
detrimental to its performance.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
2–19
Freescale Semiconductor, Inc.
MMA1220D
OPERATING CHARACTERISTICS
(Unless otherwise noted: –40°C
v TA v +85°C, 4.75 v VDD v 5.25, Acceleration = 0g, Loaded output(1))
Characteristic
Operating Range(2)
Supply Voltage(3)
Supply Current
Operating Temperature Range
Acceleration Range
Freescale Semiconductor, Inc...
Output Signal
Zero g (VDD = 5.0 V)(4)
Zero g
Sensitivity (TA = 25°C, VDD = 5.0 V)(5)
Sensitivity
Bandwidth Response
Nonlinearity
Noise
RMS (10 Hz – 1 kHz)
Clock Noise (without RC load on output)(6)
Self–Test
Output Response
Input Low
Input High
Input Loading(7)
Response Time(8)
Symbol
Min
Typ
Max
Unit
VDD
IDD
TA
gFS
4.75
3.0
40
—
5.00
5.0
—
8.0
5.25
6.0
+85
—
V
mA
°C
g
VOFF
VOFF,V
S
SV
f –3dB
NLOUT
2.25
0.45 VDD
237.5
46.5
150
1.0
2.5
0.50 VDD
250
50
250
—
2.75
0.55 VDD
262.5
53.5
350
+3.0
V
V
mV/g
mV/g/V
Hz
% FSO
nRMS
nCLK
—
—
—
2.0
6.0
—
mVrms
mVpk
0.3 VDD
0.3 VDD
VDD
200
10
V
V
V
µA
ms
DVST
*
*
VIL
VIH
IIN
tST
0.2 VDD
VSS
0.7 VDD
50
—
Status(12)(13)
Output Low (Iload = 100 µA)
Output High (Iload = 100 µA)
VOL
VOH
—
VDD 0.8
—
—
0.4
—
V
V
Minimum Supply Voltage (LVD Trip)
VLVD
2.7
3.25
4.0
V
fmin
50
—
260
kHz
tDELAY
VFSO
CL
ZO
—
VSS+0.25
—
—
2.0
—
—
300
—
VDD 0.25
100
—
*
ms
V
pF
Ω
VXZ,YZ
fPKG
—
—
—
10
5.0
—
% FSO
kHz
Clock Monitor Fail Detection Frequency
Output Stage Performance
Electrical Saturation Recovery Time(9)
Full Scale Output Range (IOUT = 200 µA)
Capacitive Load Drive(10)
Output Impedance
Mechanical Characteristics
Transverse Sensitivity(11)
Package Resonance
*
*
—
—
—
100
2.0
*
*
NOTES:
1. For a loaded output the measurements are observed after an RC filter consisting of a 1 kΩ resistor and a 0.01 µF capacitor to ground.
2. These limits define the range of operation for which the part will meet specification.
3. Within the supply range of 4.75 and 5.25 volts, the device operates as a fully calibrated linear accelerometer. Beyond these supply limits
the device may operate as a linear device but is not guaranteed to be in calibration.
4. The device can measure both + and acceleration. With no input acceleration the output is at midsupply. For positive acceleration the output
will increase above VDD/2 and for negative acceleration the output will decrease below VDD/2.
5. The device is calibrated at 20g, 100 Hz. Sensitivity limits apply to 0 Hz acceleration.
6. At clock frequency
70 kHz.
7. The digital input pin has an internal pull–down current source to prevent inadvertent self test initiation due to external board level leakages.
8. Time for the output to reach 90% of its final value after a self–test is initiated.
9. Time for amplifiers to recover after an acceleration signal causing them to saturate.
10. Preserves phase margin (60°) to guarantee output amplifier stability.
11. A measure of the device’s ability to reject an acceleration applied 90° from the true axis of sensitivity.
12. The Status pin output is not valid following power–up until at least one rising edge has been applied to the self–test pin. The Status pin is
high whenever the self–test input is high.
13. The Status pin output latches high if a Low Voltage Detection or Clock Frequency failure occurs, or the EPROM parity changes to odd. The
Status pin can be reset by a rising edge on self–test, unless a fault condition continues to exist.
*
^
2–20
For www.motorola.com/semiconductors
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
Freescale Semiconductor, Inc...
PRINCIPLE OF OPERATION
The Motorola accelerometer is a surface–micromachined
integrated–circuit accelerometer.
The device consists of a surface micromachined capacitive sensing cell (g–cell) and a CMOS signal conditioning
ASIC contained in a single integrated circuit package. The
sensing element is sealed hermetically at the wafer level
using a bulk micromachined “cap’’ wafer.
The g–cell is a mechanical structure formed from semiconductor materials (polysilicon) using semiconductor processes (masking and etching). It can be modeled as two
stationary plates with a moveable plate in–between. The
center plate can be deflected from its rest position by subjecting the system to an acceleration (Figure 2).
When the center plate deflects, the distance from it to one
fixed plate will increase by the same amount that the distance to the other plate decreases. The change in distance is
a measure of acceleration.
The g–cell plates form two back–to–back capacitors
(Figure 3). As the center plate moves with acceleration, the
distance between the plates changes and each capacitor’s
value will change, (C = Aε/D). Where A is the area of the
plate, ε is the dielectric constant, and D is the distance
between the plates.
The CMOS ASIC uses switched capacitor techniques to
measure the g–cell capacitors and extract the acceleration
data from the difference between the two capacitors. The
ASIC also signal conditions and filters (switched capacitor)
the signal, providing a high level output voltage that is ratiometric and proportional to acceleration.
Acceleration
Figure 2. Transducer
Physical Model
Motorola Sensor Device Data
Figure 3. Equivalent
Circuit Model
MMA1220D
SPECIAL FEATURES
Filtering
The Motorola accelerometers contain an onboard 4–pole
switched capacitor filter. A Bessel implementation is used
because it provides a maximally flat delay response (linear
phase) thus preserving pulse shape integrity. Because the filter is realized using switched capacitor techniques, there is
no requirement for external passive components (resistors
and capacitors) to set the cut–off frequency.
Self–Test
The sensor provides a self–test feature that allows the
verification of the mechanical and electrical integrity of the
accelerometer at any time before or after installation. This
feature is critical in applications such as automotive airbag
systems where system integrity must be ensured over the life
of the vehicle. A fourth “plate’’ is used in the g–cell as a self–
test plate. When the user applies a logic high input to the
self–test pin, a calibrated potential is applied across the
self–test plate and the moveable plate. The resulting electrostatic force (Fe = 1/2 AV2/d2) causes the center plate to
deflect. The resultant deflection is measured by the accelerometer’s control ASIC and a proportional output voltage
results. This procedure assures that both the mechanical
(g–cell) and electronic sections of the accelerometer are
functioning.
Ratiometricity
Ratiometricity simply means that the output offset voltage
and sensitivity will scale linearly with applied supply voltage.
That is, as you increase supply voltage the sensitivity and
offset increase linearly; as supply voltage decreases, offset
and sensitivity decrease linearly. This is a key feature when
interfacing to a microcontroller or an A/D converter because
it provides system level cancellation of supply induced errors
in the analog to digital conversion process.
Status
Motorola accelerometers include fault detection circuitry
and a fault latch. The Status pin is an output from the fault
latch, OR’d with self–test, and is set high whenever one (or
more) of the following events occur:
• Supply voltage falls below the Low Voltage Detect (LVD)
voltage threshold
• Clock oscillator falls below the clock monitor minimum
frequency
• Parity of the EPROM bits becomes odd in number.
The fault latch can be reset by a rising edge on the self–
test input pin, unless one (or more) of the fault conditions
continues to exist.
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2–21
Freescale Semiconductor, Inc.
MMA1220D
PCB Layout
BASIC CONNECTIONS
Pinout Description
ST
VOUT
STATUS
Freescale Semiconductor, Inc...
VSS
VDD
N/C
9
N/C
ACCELEROMETER
N/C
N/C
16
15
14
13
12
11
10
N/C
N/C
N/C
N/C
N/C
N/C
Description
1 thru 3
VSS
Redundant connections to the internal
VSS and may be left unconnected.
4
ST
Logic input pin used to initiate self–
test.
5
VOUT
STATUS
Output voltage of the accelerometer.
8
9 thru 13
Trim pins
Used for factory trim.
Leave unconnected.
14 thru 16
—
No internal connection.
Leave unconnected.
8 VDD
7 VSS
C 0.1 µF
VRH
C 0.1 µF
VDD
0.1 µF
Figure 5. Recommended PCB Layout for Interfacing
Accelerometer to Microcontroller
6
VOUT
5
• Physical coupling distance of the accelerometer to the
microcontroller should be minimal.
• Place a ground plane beneath the accelerometer to reduce
noise, the ground plane should be attached to all of the
open ended terminals shown in Figure 4.
STATUS
R1
1 kΩ
OUTPUT
SIGNAL
C2
0.01 µF
Figure 4. SOIC Accelerometer with Recommended
Connection Diagram
2–22
C 0.01 µF
• Use a 0.1 µF capacitor on VDD to decouple the power
source.
The power supply input.
4 ST
C1
0.1 µF
VDD
1 kΩ
VSS
NOTES:
The power supply ground.
MMA1220D
LOGIC
INPUT
VSS
A/D IN
R
Logic output pin used to indicate fault.
VSS
VDD
VDD
VOUT
P0
POWER SUPPLY
Pin Name
7
ST
C
Pin No.
6
P1
MICROCONTROLLER
1
2
3
4
5
6
7
8
N/C
STATUS
• Use an RC filter of 1 kΩ and 0.01 µF on the output of the
accelerometer to minimize clock noise (from the switched
capacitor filter circuit).
• PCB layout of power and ground should not couple power
supply noise.
• Accelerometer and microcontroller should not be a high
current path.
• A/D sampling rate and any external power supply switching
frequency should be selected such that they do not interfere with the internal accelerometer sampling frequency.
This will prevent aliasing errors.
For www.motorola.com/semiconductors
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MMA1220D
ACCELERATION SENSING DIRECTIONS
DYNAMIC ACCELERATION
N/C
N/C
N/C
+g
[ VOUT > 2.75 ]
ST
VOUT
STATUS
VSS
VDD
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
N/C
N/C
N/C
N/C
N/C
N/C
N/C
N/C
Freescale Semiconductor, Inc...
16–Pin SOIC Package
–g
N/C pins are recommended to be left FLOATING
[ VOUT < 2.75 ]
STATIC ACCELERATION
Direction of Earth’s gravity field.*
+1g
VOUT = 2.75V
0g
0g
VOUT = 2.50V
VOUT = 2.50V
–1g
VOUT = 2.25V
* When positioned as shown, the Earth’s gravity will result in a positive 1g output
Motorola Sensor Device Data
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Information On This Product,
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2–23
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
Low G
Micromachined Accelerometer
MMA1250D
The MMA series of silicon capacitive, micromachined accelerometers
features signal conditioning, a 2–pole low pass filter and temperature
compensation. Zero–g offset full scale span and filter cut–off are factory set and
require no external devices. A full system self–test capability verifies system
functionality.
MMA1250D: Z AXIS SENSITIVITY
MICROMACHINED
ACCELEROMETER
± 5g
Features
• Integral Signal Conditioning
• Linear Output
Freescale Semiconductor, Inc...
• 2nd Order Bessel Filter
• Calibrated Self–test
• EPROM Parity Check Status
16
• Transducer Hermetically Sealed at Wafer Level for Superior Reliability
9
• Robust Design, High Shock Survivability
1
Typical Applications
8
• Vibration Monitoring and Recording
16 LEAD SOIC
CASE 475
• Appliance Control
• Mechanical Bearing Monitoring
• Computer Hard Drive Protection
• Computer Mouse and Joysticks
Pin Assignment
• Virtual Reality Input Devices
VSS
VOUT
ORDERING INFORMATION
Device
Temperature Range
MMA1250D
–40 to +105°C
Case No.
Package
Case 475–01
SOIC–16
16
15
14
13
12
11
10
1
2
3
4
5
6
7
8
VSS
VSS
• Sports Diagnostic Devices and Systems
STATUS
VDD
VSS
ST
9
N/C
N/C
N/C
N/C
N/C
N/C
N/C
N/C
SIMPLIFIED ACCELEROMETER FUNCTIONAL BLOCK DIAGRAM
VDD
G–CELL
SENSOR
ST
SELF–TEST
INTEGRATOR
GAIN
CONTROL LOGIC &
EPROM TRIM CIRCUITS
FILTER
OSCILLATOR
TEMP COMP
& GAIN
VOUT
CLOCK GEN.
VSS
STATUS
Figure 1. Simplified Accelerometer Functional Block Diagram
REV 1
2–24
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MMA1250D
MAXIMUM RATINGS (Maximum ratings are the limits to which the device can be exposed without causing permanent damage.)
Symbol
Value
Unit
Powered Acceleration (all axes)
Rating
gpd
1500
g
Unpowered Acceleration (all axes)
gupd
2000
g
Supply Voltage
VDD
–0.3 to +7.0
V
Hdrop
1.2
m
Tstg
– 40 to +125
°C
Drop Test(1)
Storage Temperature Range
NOTES:
1. Dropped onto concrete surface from any axis.
Freescale Semiconductor, Inc...
ELECTRO STATIC DISCHARGE (ESD)
WARNING: This device is sensitive to electrostatic
discharge.
Although the Motorola accelerometers contain internal
2kV ESD protection circuitry, extra precaution must be taken
by the user to protect the chip from ESD. A charge of over
Motorola Sensor Device Data
2000 volts can accumulate on the human body or associated
test equipment. A charge of this magnitude can alter the performance or cause failure of the chip. When handling the accelerometer, proper ESD precautions should be followed to
avoid exposing the device to discharges which may be detrimental to its performance.
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2–25
Freescale Semiconductor, Inc.
MMA1250D
OPERATING CHARACTERISTICS
(Unless otherwise noted: –40°C
v TA v +105°C, 4.75 v VDD v 5.25, Acceleration = 0g, Loaded output(1))
Characteristic
Symbol
Min
Typ
Max
Unit
VDD
IDD
TA
gFS
4.75
1.1
40
—
*
5.00
2.1
—
5
5.25
3.0
+105
—
V
mA
°C
g
2.25
2.0
380
370
42.5
1.0
2.5
2.5
400
400
50
—
2.75
3.0
420
430.1
57.5
+1.0
V
V
mV/g
mV/g
Hz
% FSO
—
—
2.0
700
4.0
—
mVrms
µg/√Hz
VIL
VIH
IIN
tST
1.0
VSS
0.7 VDD
50
—
1.25
—
—
125
10
1.5
0.3 VDD
VDD
300
25
V
V
V
µA
ms
VOL
VOH
—
VDD 0.8
—
—
0.4
—
V
V
Output Stage Performance
Electrical Saturation Recovery Time(9)
Full Scale Output Range (IOUT = –200 µA)
Capacitive Load Drive(10)
Output Impedance
tDELAY
VFSO
CL
ZO
—
VSS+0.25
—
—
—
—
—
50
2.0
VDD 0.25
100
—
*
ms
V
pF
Ω
Mechanical Characteristics
Transverse Sensitivity(11)
VXZ,YZ
—
—
5.0
% FSO
Operating Range(2)
Supply Voltage(3)
Supply Current
Operating Temperature Range
Acceleration Range
Freescale Semiconductor, Inc...
Output Signal
Zero g (TA = 25°C, VDD = 5.0 V)(4)
Zero g (VDD = 5.0 V)
Sensitivity (TA = 25°C, VDD = 5.0 V)(5)
Sensitivity (VDD = 5.0 V)
Bandwidth Response
Nonlinearity
VOFF
VOFF
S
S
f –3dB
NLOUT
Noise
RMS (0.1 Hz – 1.0 kHz)
Spectral Density (RMS, 0.1 Hz – 1.0 kHz)(6)
Self–Test
Output Response (VDD = 5.0 V)
Input Low
Input High
Input Loading(7)
Response Time(8)
nRMS
nSD
DVST
Status(12)(13)
Output Low (Iload = 100 µA)
Output High (Iload = –100 µA)
*
*
*
*
*
NOTES:
1. For a loaded output the measurements are observed after an RC filter consisting of a 1 kΩ resistor and a 0.1 µF capacitor to ground.
2. These limits define the range of operation for which the part will meet specification.
3. Within the supply range of 4.75 and 5.25 volts, the device operates as a fully calibrated linear accelerometer. Beyond these supply limits
the device may operate as a linear device but is not guaranteed to be in calibration.
4. The device can measure both + and acceleration. With no input acceleration the output is at midsupply. For positive acceleration the output
will increase above VDD/2 and for negative acceleration the output will decrease below VDD/2.
5. Sensitivity limits apply to 0 Hz acceleration.
6. At clock frequency
35 kHz.
7. The digital input pin has an internal pull–down current source to prevent inadvertent self test initiation due to external board level leakages.
8. Time for the output to reach 90% of its final value after a self–test is initiated.
9. Time for amplifiers to recover after an acceleration signal causing them to saturate.
10. Preserves phase margin (60°) to guarantee output amplifier stability.
11. A measure of the device’s ability to reject an acceleration applied 90° from the true axis of sensitivity.
12. The Status pin output is not valid following power–up until at least one rising edge has been applied to the self–test pin. The Status pin is
high whenever the self–test input is high.
13. The Status pin output latches high if the EPROM parity changes to odd. The Status pin can be reset by a rising edge on self–test, unless
a fault condition continues to exist.
*
^
2–26
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc...
Freescale Semiconductor, Inc.
MMA1250D
PRINCIPLE OF OPERATION
SPECIAL FEATURES
The Motorola accelerometer is a surface–micromachined
integrated–circuit accelerometer.
The device consists of a surface micromachined capacitive sensing cell (g–cell) and a CMOS signal conditioning
ASIC contained in a single integrated circuit package. The
sensing element is sealed hermetically at the wafer level using a bulk micromachined “cap’’ wafer.
The g–cell is a mechanical structure formed from semiconductor materials (polysilicon) using semiconductor processes (masking and etching). It can be modeled as two
stationary plates with a moveable plate in–between. The
center plate can be deflected from its rest position by subjecting the system to an acceleration (Figure 2).
When the center plate deflects, the distance from it to one
fixed plate will increase by the same amount that the distance to the other plate decreases. The change in distance is
a measure of acceleration.
The g–cell plates form two back–to–back capacitors (Figure 3). As the center plate moves with acceleration, the distance between the plates changes and each capacitor’s
value will change, (C = Aε/D). Where A is the area of the
plate, ε is the dielectric constant, and D is the distance between the plates.
The CMOS ASIC uses switched capacitor techniques to
measure the g–cell capacitors and extract the acceleration
data from the difference between the two capacitors. The
ASIC also signal conditions and filters (switched capacitor)
the signal, providing a high level output voltage that is ratiometric and proportional to acceleration.
Filtering
The Motorola accelerometers contain an onboard 2–pole
switched capacitor filter. A Bessel implementation is used
because it provides a maximally flat delay response (linear
phase) thus preserving pulse shape integrity. Because the filter is realized using switched capacitor techniques, there is
no requirement for external passive components (resistors
and capacitors) to set the cut–off frequency.
Self–Test
The sensor provides a self–test feature that allows the verification of the mechanical and electrical integrity of the accelerometer at any time before or after installation. This
feature is critical in applications such as automotive airbag
systems where system integrity must be ensured over the life
of the vehicle. A fourth “plate’’ is used in the g–cell as a self–
test plate. When the user applies a logic high input to the
self–test pin, a calibrated potential is applied across the
self–test plate and the moveable plate. The resulting electrostatic force (Fe = 1/2 AV2/d2) causes the center plate to
deflect. The resultant deflection is measured by the accelerometer’s control ASIC and a proportional output voltage results. This procedure assures that both the mechanical
(g–cell) and electronic sections of the accelerometer are
functioning.
Acceleration
Status
Motorola accelerometers include fault detection circuitry
and a fault latch. The Status pin is an output from the fault
latch, OR’d with self–test, and is set high whenever the following event occurs:
Figure 2. Transducer
Physical Model
Motorola Sensor Device Data
Figure 3. Equivalent
Circuit Model
• Parity of the EPROM bits becomes odd in number.
The fault latch can be reset by a rising edge on the self–
test input pin, unless one (or more) of the fault conditions
continues to exist.
www.motorola.com/semiconductors
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Information On This Product,
Go to: www.freescale.com
2–27
Freescale Semiconductor, Inc.
MMA1250D
PCB Layout
BASIC CONNECTIONS
VSS
ST
N/C
9
N/C
STATUS
ACCELEROMETER
VOUT
STATUS
VDD
16
15
14
13
12
11
10
N/C
N/C
N/C
N/C
N/C
N/C
P1
ST
VOUT
VSS
VDD
P0
A/D IN
R
1 kΩ
0.1 µF
C
C 0.1 µF
VRH
C
MICROCONTROLLER
1
2
3
4
5
6
7
8
VSS
VSS
VSS
VSS
C 0.1 µF
VDD
0.1 µF
Freescale Semiconductor, Inc...
Figure 4. Pinout Description
POWER SUPPLY
Pin No.
Pin Name
Description
1 thru 3
VSS
Redundant connections to the internal
VSS and may be left unconnected.
4
VOUT
STATUS
5
6
Output voltage of the accelerometer.
Logic output pin used to indicate fault.
7
VDD
VSS
8
ST
9 thru 13
Trim pins
Used for factory trim.
Leave unconnected.
14 thru 16
—
No internal connection.
Leave unconnected.
VDD
C1
0.1 µF
The power supply input.
The power supply ground.
NOTES:
Logic input pin used to initiate self–
test.
• Use a 0.1 µF capacitor on VDD to decouple the power
source.
MMA1250D
LOGIC
INPUT
5
8 ST
1
2
3
6 VDD
VSS
VSS
VSS
7 VSS
VOUT
4
• Physical coupling distance of the accelerometer to the microcontroller should be minimal.
• Place a ground plane beneath the accelerometer to reduce
noise, the ground plane should be attached to all internal
VSS terminals shown in Figure 4.
STATUS
R1
1 kΩ
OUTPUT
SIGNAL
C2
0.1 µF
Figure 5. SOIC Accelerometer with Recommended
Connection Diagram
2–28
Figure 6. Recommended PCB Layout for Interfacing
Accelerometer to Microcontroller
• Use an RC filter of 1 kΩ and 0.1 µF on the output of the accelerometer to minimize clock noise (from the switched
capacitor filter circuit).
• PCB layout of power and ground should not couple power
supply noise.
• Accelerometer and microcontroller should not be a high
current path.
• A/D sampling rate and any external power supply switching
frequency should be selected such that they do not interfere with the internal accelerometer sampling frequency.
This will prevent aliasing errors.
For www.motorola.com/semiconductors
More Information On This Product,
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MMA1250D
ACCELERATION SENSING DIRECTIONS
DYNAMIC ACCELERATION
VSS
VSS
VSS
+g
VOUT
STATUS
VDD
VSS
ST
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
N/C
N/C
N/C
N/C
N/C
N/C
N/C
N/C
Freescale Semiconductor, Inc...
16–Pin SOIC Package
N/C pins are recommended to be left FLOATING
–g
STATIC ACCELERATION
Direction of Earth’s gravity field.*
+1g
VOUT = 2.9V
0g
0g
VOUT = 2.50V
VOUT = 2.50V
–1g
VOUT = 2.1V
* When positioned as shown, the Earth’s gravity will result in a positive 1g output
Motorola Sensor Device Data
www.motorola.com/semiconductors
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Information On This Product,
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2–29
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
Low G
Micromachined Accelerometer
MMA1260D
The MMA series of silicon capacitive, micromachined accelerometers
features signal conditioning, a 2–pole low pass filter and temperature
compensation. Zero–g offset full scale span and filter cut–off are factory set and
require no external devices. A full system self–test capability verifies system
functionality.
MMA1260D: Z AXIS SENSITIVITY
MICROMACHINED
ACCELEROMETER
± 1.5g
Features
• Integral Signal Conditioning
• Linear Output
Freescale Semiconductor, Inc...
• 2nd Order Bessel Filter
• Calibrated Self–test
• EPROM Parity Check Status
16
• Transducer Hermetically Sealed at Wafer Level for Superior Reliability
9
• Robust Design, High Shock Survivability
1
Typical Applications
8
• Vibration Monitoring and Recording
16 LEAD SOIC
CASE 475
• Appliance Control
• Mechanical Bearing Monitoring
• Computer Hard Drive Protection
• Computer Mouse and Joysticks
Pin Assignment
• Virtual Reality Input Devices
VSS
VOUT
ORDERING INFORMATION
Device
Temperature Range
MMA1260D
–40 to +105°C
Case No.
Package
Case 475–01
SOIC–16
16
15
14
13
12
11
10
1
2
3
4
5
6
7
8
VSS
VSS
• Sports Diagnostic Devices and Systems
STATUS
VDD
VSS
ST
9
N/C
N/C
N/C
N/C
N/C
N/C
N/C
N/C
SIMPLIFIED ACCELEROMETER FUNCTIONAL BLOCK DIAGRAM
VDD
G–CELL
SENSOR
ST
SELF–TEST
INTEGRATOR
GAIN
CONTROL LOGIC &
EPROM TRIM CIRCUITS
FILTER
OSCILLATOR
TEMP COMP
& GAIN
VOUT
CLOCK GEN.
VSS
STATUS
Figure 1. Simplified Accelerometer Functional Block Diagram
REV 1
2–30
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MMA1260D
MAXIMUM RATINGS (Maximum ratings are the limits to which the device can be exposed without causing permanent damage.)
Symbol
Value
Unit
Powered Acceleration (all axes)
Rating
gpd
1500
g
Unpowered Acceleration (all axes)
gupd
2000
g
Supply Voltage
VDD
–0.3 to +7.0
V
Hdrop
1.2
m
Tstg
– 40 to +125
°C
Drop Test(1)
Storage Temperature Range
NOTES:
1. Dropped onto concrete surface from any axis.
Freescale Semiconductor, Inc...
ELECTRO STATIC DISCHARGE (ESD)
WARNING: This device is sensitive to electrostatic
discharge.
Although the Motorola accelerometers contain internal
2kV ESD protection circuitry, extra precaution must be taken
by the user to protect the chip from ESD. A charge of over
Motorola Sensor Device Data
2000 volts can accumulate on the human body or associated
test equipment. A charge of this magnitude can alter the performance or cause failure of the chip. When handling the accelerometer, proper ESD precautions should be followed to
avoid exposing the device to discharges which may be detrimental to its performance.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
2–31
Freescale Semiconductor, Inc.
MMA1260D
OPERATING CHARACTERISTICS
(Unless otherwise noted: –40°C
v TA v +105°C, 4.75 v VDD v 5.25, Acceleration = 0g, Loaded output(1))
Characteristic
Operating Range(2)
Supply Voltage(3)
Supply Current
Operating Temperature Range
Acceleration Range
Freescale Semiconductor, Inc...
Output Signal
Zero g (TA = 25°C, VDD = 5.0 V)(4)
Zero g (VDD = 5.0 V)
Sensitivity (TA = 25°C, VDD = 5.0 V)(5)
Sensitivity (VDD = 5.0 V)
Bandwidth Response
Nonlinearity
Symbol
Min
Typ
Max
Unit
VDD
IDD
TA
gFS
4.75
1.1
40
—
*
5.00
2.2
—
1.5
5.25
3.2
+105
—
V
mA
°C
g
2.25
2.2
1140
1110
40
1.0
2.5
2.5
1200
1200
50
—
2.75
2.8
1260
1290
60
+1.0
V
V
mV/g
mV/g
Hz
% FSO
—
—
5.0
500
9.0
—
mVrms
µg/√Hz
0.9
0.3 VDD
VDD
300
25
V
V
V
µA
ms
VOFF
VOFF
S
S
f –3dB
NLOUT
Noise
RMS (0.1 Hz – 1.0 kHz)
Spectral Density (RMS, 0.1 Hz – 1.0 kHz)(6)
Self–Test
Output Response (VDD = 5.0 V)
Input Low
Input High
Input Loading(7)
Response Time(8)
nRMS
nSD
DVST
*
VIL
VIH
IIN
tST
0.3
VSS
0.7 VDD
50
—
VOL
VOH
—
VDD 0.8
—
—
0.4
—
V
V
Output Stage Performance
Electrical Saturation Recovery Time(9)
Full Scale Output Range (IOUT = –200 µA)
Capacitive Load Drive(10)
Output Impedance
tDELAY
VFSO
CL
ZO
—
VSS+0.25
—
—
—
—
—
50
2.0
VDD 0.25
100
—
*
ms
V
pF
Ω
Mechanical Characteristics
Transverse Sensitivity(11)
VXZ,YZ
—
—
5.0
% FSO
Status(12)(13)
Output Low (Iload = 100 µA)
Output High (Iload = –100 µA)
*
*
0.6
—
—
125
10
*
*
NOTES:
1. For a loaded output the measurements are observed after an RC filter consisting of a 1 kΩ resistor and a 0.1 µF capacitor to ground.
2. These limits define the range of operation for which the part will meet specification.
3. Within the supply range of 4.75 and 5.25 volts, the device operates as a fully calibrated linear accelerometer. Beyond these supply limits
the device may operate as a linear device but is not guaranteed to be in calibration.
4. The device can measure both + and acceleration. With no input acceleration the output is at midsupply. For positive acceleration the output
will increase above VDD/2 and for negative acceleration the output will decrease below VDD/2.
5. Sensitivity limits apply to 0 Hz acceleration.
6. At clock frequency
35 kHz.
7. The digital input pin has an internal pull–down current source to prevent inadvertent self test initiation due to external board level leakages.
8. Time for the output to reach 90% of its final value after a self–test is initiated.
9. Time for amplifiers to recover after an acceleration signal causing them to saturate.
10. Preserves phase margin (60°) to guarantee output amplifier stability.
11. A measure of the device’s ability to reject an acceleration applied 90° from the true axis of sensitivity.
12. The Status pin output is not valid following power–up until at least one rising edge has been applied to the self–test pin. The Status pin is
high whenever the self–test input is high.
13. The Status pin output latches high if the EPROM parity changes to odd. The Status pin can be reset by a rising edge on self–test, unless
a fault condition continues to exist.
*
^
2–32
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc...
Freescale Semiconductor, Inc.
MMA1260D
PRINCIPLE OF OPERATION
SPECIAL FEATURES
The Motorola accelerometer is a surface–micromachined
integrated–circuit accelerometer.
The device consists of a surface micromachined capacitive sensing cell (g–cell) and a CMOS signal conditioning
ASIC contained in a single integrated circuit package. The
sensing element is sealed hermetically at the wafer level using a bulk micromachined “cap’’ wafer.
The g–cell is a mechanical structure formed from semiconductor materials (polysilicon) using semiconductor processes (masking and etching). It can be modeled as two
stationary plates with a moveable plate in–between. The
center plate can be deflected from its rest position by subjecting the system to an acceleration (Figure 2).
When the center plate deflects, the distance from it to one
fixed plate will increase by the same amount that the distance to the other plate decreases. The change in distance is
a measure of acceleration.
The g–cell plates form two back–to–back capacitors (Figure 3). As the center plate moves with acceleration, the distance between the plates changes and each capacitor’s
value will change, (C = Aε/D). Where A is the area of the
plate, ε is the dielectric constant, and D is the distance between the plates.
The CMOS ASIC uses switched capacitor techniques to
measure the g–cell capacitors and extract the acceleration
data from the difference between the two capacitors. The
ASIC also signal conditions and filters (switched capacitor)
the signal, providing a high level output voltage that is ratiometric and proportional to acceleration.
Filtering
The Motorola accelerometers contain an onboard 2–pole
switched capacitor filter. A Bessel implementation is used
because it provides a maximally flat delay response (linear
phase) thus preserving pulse shape integrity. Because the filter is realized using switched capacitor techniques, there is
no requirement for external passive components (resistors
and capacitors) to set the cut–off frequency.
Self–Test
The sensor provides a self–test feature that allows the verification of the mechanical and electrical integrity of the accelerometer at any time before or after installation. This
feature is critical in applications such as automotive airbag
systems where system integrity must be ensured over the life
of the vehicle. A fourth “plate’’ is used in the g–cell as a self–
test plate. When the user applies a logic high input to the
self–test pin, a calibrated potential is applied across the
self–test plate and the moveable plate. The resulting electrostatic force (Fe = 1/2 AV2/d2) causes the center plate to
deflect. The resultant deflection is measured by the accelerometer’s control ASIC and a proportional output voltage results. This procedure assures that both the mechanical
(g–cell) and electronic sections of the accelerometer are
functioning.
Acceleration
Status
Motorola accelerometers include fault detection circuitry
and a fault latch. The Status pin is an output from the fault
latch, OR’d with self–test, and is set high whenever the following event occurs:
Figure 2. Transducer
Physical Model
Motorola Sensor Device Data
Figure 3. Equivalent
Circuit Model
• Parity of the EPROM bits becomes odd in number.
The fault latch can be reset by a rising edge on the self–
test input pin, unless one (or more) of the fault conditions
continues to exist.
www.motorola.com/semiconductors
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Information On This Product,
Go to: www.freescale.com
2–33
Freescale Semiconductor, Inc.
MMA1260D
PCB Layout
BASIC CONNECTIONS
VSS
ST
N/C
9
N/C
STATUS
ACCELEROMETER
VOUT
STATUS
VDD
16
15
14
13
12
11
10
N/C
N/C
N/C
N/C
N/C
N/C
P1
ST
VOUT
VSS
VDD
P0
A/D IN
R
1 kΩ
0.1 µF
C
C 0.1 µF
VRH
C
MICROCONTROLLER
1
2
3
4
5
6
7
8
VSS
VSS
VSS
VSS
C 0.1 µF
VDD
0.1 µF
Figure 4. Pinout Description
Freescale Semiconductor, Inc...
POWER SUPPLY
Pin No.
Pin Name
Description
1 thru 3
VSS
Redundant connections to the internal
VSS and may be left unconnected.
4
VOUT
STATUS
5
6
7
VDD
VSS
8
ST
9 thru 13
14 thru 16
VDD
C1
0.1 µF
Output voltage of the accelerometer.
Logic output pin used to indicate fault.
The power supply input.
The power supply ground.
NOTES:
Logic input pin used to initiate self–
test.
• Use a 0.1 µF capacitor on VDD to decouple the power
source.
Trim pins
Used for factory trim.
Leave unconnected.
—
No internal connection.
Leave unconnected.
• Physical coupling distance of the accelerometer to the microcontroller should be minimal.
MMA1260D
LOGIC
INPUT
5
8 ST
1
2
3
6 VDD
VSS
VSS
VSS
7 VSS
VOUT 4
STATUS
R1
1 kΩ
OUTPUT
SIGNAL
C2
0.1 µF
Figure 5. SOIC Accelerometer with Recommended
Connection Diagram
2–34
Figure 6. Recommended PCB Layout for Interfacing
Accelerometer to Microcontroller
• Place a ground plane beneath the accelerometer to reduce
noise, the ground plane should be attached to all internal
VSS terminals shown in Figure 4.
• Use an RC filter of 1 kΩ and 0.1 µF on the output of the accelerometer to minimize clock noise (from the switched
capacitor filter circuit).
• PCB layout of power and ground should not couple power
supply noise.
• Accelerometer and microcontroller should not be a high
current path.
• A/D sampling rate and any external power supply switching
frequency should be selected such that they do not interfere with the internal accelerometer sampling frequency.
This will prevent aliasing errors.
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MMA1260D
ACCELERATION SENSING DIRECTIONS
DYNAMIC ACCELERATION
VSS
VSS
VSS
+g
VOUT
STATUS
VDD
VSS
ST
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
N/C
N/C
N/C
N/C
N/C
N/C
N/C
N/C
Freescale Semiconductor, Inc...
16–Pin SOIC Package
N/C pins are recommended to be left FLOATING
–g
STATIC ACCELERATION
Direction of Earth’s gravity field.*
+1g
VOUT = 3.7V
0g
0g
VOUT = 2.50V
VOUT = 2.50V
–1g
VOUT = 1.3V
* When positioned as shown, the Earth’s gravity will result in a positive 1g output
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
2–35
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
Low G
Micromachined Accelerometer
MMA1270D
The MMA series of silicon capacitive, micromachined accelerometers
features signal conditioning, a 2–pole low pass filter and temperature
compensation. Zero–g offset full scale span and filter cut–off are factory set and
require no external devices. A full system self–test capability verifies system
functionality.
MMA1270D: Z AXIS SENSITIVITY
MICROMACHINED
ACCELEROMETER
± 2.5g
Features
• Integral Signal Conditioning
• Linear Output
Freescale Semiconductor, Inc...
• 2nd Order Bessel Filter
• Calibrated Self–test
• EPROM Parity Check Status
16
• Transducer Hermetically Sealed at Wafer Level for Superior Reliability
9
• Robust Design, High Shock Survivability
1
Typical Applications
8
• Vibration Monitoring and Recording
16 LEAD SOIC
CASE 475
• Appliance Control
• Mechanical Bearing Monitoring
• Computer Hard Drive Protection
• Computer Mouse and Joysticks
Pin Assignment
• Virtual Reality Input Devices
VSS
VOUT
ORDERING INFORMATION
Device
Temperature Range
MMA1270D
–40 to +105°C
Case No.
Package
Case 475–01
SOIC–16
16
15
14
13
12
11
10
1
2
3
4
5
6
7
8
VSS
VSS
• Sports Diagnostic Devices and Systems
STATUS
VDD
VSS
ST
9
N/C
N/C
N/C
N/C
N/C
N/C
N/C
N/C
SIMPLIFIED ACCELEROMETER FUNCTIONAL BLOCK DIAGRAM
VDD
G–CELL
SENSOR
ST
SELF–TEST
INTEGRATOR
GAIN
CONTROL LOGIC &
EPROM TRIM CIRCUITS
FILTER
OSCILLATOR
TEMP COMP
& GAIN
VOUT
CLOCK GEN.
VSS
STATUS
Figure 1. Simplified Accelerometer Functional Block Diagram
REV 1
2–36
For www.motorola.com/semiconductors
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MMA1270D
MAXIMUM RATINGS (Maximum ratings are the limits to which the device can be exposed without causing permanent damage.)
Symbol
Value
Unit
Powered Acceleration (all axes)
Rating
gpd
1500
g
Unpowered Acceleration (all axes)
gupd
2000
g
Supply Voltage
VDD
–0.3 to +7.0
V
Hdrop
1.2
m
Tstg
– 40 to +125
°C
Drop Test(1)
Storage Temperature Range
NOTES:
1. Dropped onto concrete surface from any axis.
Freescale Semiconductor, Inc...
ELECTRO STATIC DISCHARGE (ESD)
WARNING: This device is sensitive to electrostatic
discharge.
Although the Motorola accelerometers contain internal
2kV ESD protection circuitry, extra precaution must be taken
by the user to protect the chip from ESD. A charge of over
Motorola Sensor Device Data
2000 volts can accumulate on the human body or associated
test equipment. A charge of this magnitude can alter the performance or cause failure of the chip. When handling the accelerometer, proper ESD precautions should be followed to
avoid exposing the device to discharges which may be detrimental to its performance.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
2–37
Freescale Semiconductor, Inc.
MMA1270D
OPERATING CHARACTERISTICS
(Unless otherwise noted: –40°C
v TA v +105°C, 4.75 v VDD v 5.25, Acceleration = 0g, Loaded output(1))
Characteristic
Symbol
Min
Typ
Max
Unit
VDD
IDD
TA
gFS
4.75
1.1
40
—
*
5.00
2.1
—
2.5
5.25
3.0
+105
—
V
mA
°C
g
VOFF
VOFF
S
S
f –3dB
NLOUT
2.25
2.2
712.5
693.8
40
1.0
2.5
2.5
750
750
50
—
2.75
2.8
787.5
806.3
60
+1.0
V
V
mV/g
mV/g
Hz
% FSO
nRMS
nSD
—
—
3.5
700
6.5
—
mVrms
µg/√Hz
VIL
VIH
IIN
tST
0.9
VSS
0.7 VDD
50
—
1.25
—
—
125
10
1.6
0.3 VDD
VDD
300
25
V
V
V
µA
ms
VOL
VOH
—
VDD 0.8
—
—
0.4
—
V
V
Output Stage Performance
Electrical Saturation Recovery Time(9)
Full Scale Output Range (IOUT = –200 µA)
Capacitive Load Drive(10)
Output Impedance
tDELAY
VFSO
CL
ZO
—
VSS+0.25
—
—
—
—
—
50
2.0
VDD 0.25
100
—
*
ms
V
pF
Ω
Mechanical Characteristics
Transverse Sensitivity(11)
VXZ,YZ
—
—
5.0
% FSO
Operating Range(2)
Supply Voltage(3)
Supply Current
Operating Temperature Range
Acceleration Range
Freescale Semiconductor, Inc...
Output Signal
Zero g (TA = 25°C, VDD = 5.0 V)(4)
Zero g (VDD = 5.0 V)
Sensitivity (TA = 25°C, VDD = 5.0 V)(5)
Sensitivity(VDD = 5.0 V)
Bandwidth Response
Nonlinearity
Noise
RMS (0.1 Hz – 1.0 kHz)
Spectral Density (RMS, 0.1 Hz – 1.0 kHz)(6)
Self–Test
Output Response (VDD = 5.0 V)
Input Low
Input High
Input Loading(7)
Response Time(8)
DVST
Status(12)(13)
Output Low (Iload = 100 µA)
Output High (Iload = –100 µA)
*
*
*
*
*
NOTES:
1. For a loaded output the measurements are observed after an RC filter consisting of a 1 kΩ resistor and a 0.1 µF capacitor to ground.
2. These limits define the range of operation for which the part will meet specification.
3. Within the supply range of 4.75 and 5.25 volts, the device operates as a fully calibrated linear accelerometer. Beyond these supply limits
the device may operate as a linear device but is not guaranteed to be in calibration.
4. The device can measure both + and acceleration. With no input acceleration the output is at midsupply. For positive acceleration the output
will increase above VDD/2 and for negative acceleration the output will decrease below VDD/2.
5. Sensitivity limits apply to 0 Hz acceleration.
6. At clock frequency
35 kHz.
7. The digital input pin has an internal pull–down current source to prevent inadvertent self test initiation due to external board level leakages.
8. Time for the output to reach 90% of its final value after a self–test is initiated.
9. Time for amplifiers to recover after an acceleration signal causing them to saturate.
10. Preserves phase margin (60°) to guarantee output amplifier stability.
11. A measure of the device’s ability to reject an acceleration applied 90° from the true axis of sensitivity.
12. The Status pin output is not valid following power–up until at least one rising edge has been applied to the self–test pin. The Status pin is
high whenever the self–test input is high.
13. The Status pin output latches high if the EPROM parity changes to odd. The Status pin can be reset by a rising edge on self–test, unless
a fault condition continues to exist.
*
^
2–38
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc...
Freescale Semiconductor, Inc.
MMA1270D
PRINCIPLE OF OPERATION
SPECIAL FEATURES
The Motorola accelerometer is a surface–micromachined
integrated–circuit accelerometer.
The device consists of a surface micromachined capacitive sensing cell (g–cell) and a CMOS signal conditioning
ASIC contained in a single integrated circuit package. The
sensing element is sealed hermetically at the wafer level using a bulk micromachined “cap’’ wafer.
The g–cell is a mechanical structure formed from semiconductor materials (polysilicon) using semiconductor processes (masking and etching). It can be modeled as two
stationary plates with a moveable plate in–between. The
center plate can be deflected from its rest position by subjecting the system to an acceleration (Figure 2).
When the center plate deflects, the distance from it to one
fixed plate will increase by the same amount that the distance to the other plate decreases. The change in distance is
a measure of acceleration.
The g–cell plates form two back–to–back capacitors (Figure 3). As the center plate moves with acceleration, the distance between the plates changes and each capacitor’s
value will change, (C = Aε/D). Where A is the area of the
plate, ε is the dielectric constant, and D is the distance between the plates.
The CMOS ASIC uses switched capacitor techniques to
measure the g–cell capacitors and extract the acceleration
data from the difference between the two capacitors. The
ASIC also signal conditions and filters (switched capacitor)
the signal, providing a high level output voltage that is ratiometric and proportional to acceleration.
Filtering
The Motorola accelerometers contain an onboard 2–pole
switched capacitor filter. A Bessel implementation is used
because it provides a maximally flat delay response (linear
phase) thus preserving pulse shape integrity. Because the filter is realized using switched capacitor techniques, there is
no requirement for external passive components (resistors
and capacitors) to set the cut–off frequency.
Self–Test
The sensor provides a self–test feature that allows the verification of the mechanical and electrical integrity of the accelerometer at any time before or after installation. This
feature is critical in applications such as automotive airbag
systems where system integrity must be ensured over the life
of the vehicle. A fourth “plate’’ is used in the g–cell as a self–
test plate. When the user applies a logic high input to the
self–test pin, a calibrated potential is applied across the
self–test plate and the moveable plate. The resulting electrostatic force (Fe = 1/2 AV2/d2) causes the center plate to
deflect. The resultant deflection is measured by the accelerometer’s control ASIC and a proportional output voltage results. This procedure assures that both the mechanical
(g–cell) and electronic sections of the accelerometer are
functioning.
Acceleration
Status
Motorola accelerometers include fault detection circuitry
and a fault latch. The Status pin is an output from the fault
latch, OR’d with self–test, and is set high whenever the following event occurs:
Figure 2. Transducer
Physical Model
Motorola Sensor Device Data
Figure 3. Equivalent
Circuit Model
• Parity of the EPROM bits becomes odd in number.
The fault latch can be reset by a rising edge on the self–
test input pin, unless one (or more) of the fault conditions
continues to exist.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
2–39
Freescale Semiconductor, Inc.
MMA1270D
PCB Layout
BASIC CONNECTIONS
VSS
ST
N/C
9
N/C
STATUS
ACCELEROMETER
VOUT
STATUS
VDD
16
15
14
13
12
11
10
N/C
N/C
N/C
N/C
N/C
N/C
P1
ST
VOUT
VSS
VDD
P0
A/D IN
R
1 kΩ
0.1 µF
C
C 0.1 µF
VRH
C
MICROCONTROLLER
1
2
3
4
5
6
7
8
VSS
VSS
VSS
VSS
C 0.1 µF
VDD
0.1 µF
Figure 4. Pinout Description
Freescale Semiconductor, Inc...
POWER SUPPLY
Pin No.
Pin Name
Description
1 thru 3
VSS
Redundant connections to the internal
VSS and may be left unconnected.
4
VOUT
STATUS
5
6
7
VDD
VSS
8
ST
9 thru 13
14 thru 16
VDD
C1
0.1 µF
Output voltage of the accelerometer.
Logic output pin used to indicate fault.
The power supply input.
The power supply ground.
NOTES:
Logic input pin used to initiate self–
test.
• Use a 0.1 µF capacitor on VDD to decouple the power
source.
Trim pins
Used for factory trim.
Leave unconnected.
—
No internal connection.
Leave unconnected.
• Physical coupling distance of the accelerometer to the microcontroller should be minimal.
MMA1270D
LOGIC
INPUT
5
8 ST
1
2
3
6 VDD
VSS
VSS
VSS
7 VSS
VOUT
4
• Place a ground plane beneath the accelerometer to reduce
noise, the ground plane should be attached to all internal
VSS terminals shown in Figure 4.
STATUS
R1
1 kΩ
OUTPUT
SIGNAL
C2
0.1 µF
Figure 5. SOIC Accelerometer with Recommended
Connection Diagram
2–40
Figure 6. Recommended PCB Layout for Interfacing
Accelerometer to Microcontroller
• Use an RC filter of 1 kΩ and 0.1 µF on the output of the accelerometer to minimize clock noise (from the switched
capacitor filter circuit).
• PCB layout of power and ground should not couple power
supply noise.
• Accelerometer and microcontroller should not be a high
current path.
• A/D sampling rate and any external power supply switching
frequency should be selected such that they do not interfere with the internal accelerometer sampling frequency.
This will prevent aliasing errors.
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MMA1270D
ACCELERATION SENSING DIRECTIONS
DYNAMIC ACCELERATION
VSS
VSS
VSS
+g
VOUT
STATUS
VDD
VSS
ST
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
N/C
N/C
N/C
N/C
N/C
N/C
N/C
N/C
Freescale Semiconductor, Inc...
16–Pin SOIC Package
N/C pins are recommended to be left FLOATING
–g
STATIC ACCELERATION
Direction of Earth’s gravity field.*
+1g
VOUT = 3.25V
0g
0g
VOUT = 2.50V
VOUT = 2.50V
–1g
VOUT = 1.75V
* When positioned as shown, the Earth’s gravity will result in a positive 1g output
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
2–41
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
MMA2201D
Surface Mount
Micromachined Accelerometer
The MMA series of silicon capacitive, micromachined accelerometers
features signal conditioning, a 4–pole low pass filter and temperature
compensation. Zero–g offset full scale span and filter cut–off are factory set and
require no external devices. A full system self–test capability verifies system
functionality.
Features
MMA2201D: X AXIS SENSITIVITY
MICROMACHINED
ACCELEROMETER
± 40g
Freescale Semiconductor, Inc...
• Integral Signal Conditioning
• Linear Output
• Ratiometric Performance
16
• 4th Order Bessel Filter Preserves Pulse Shape Integrity
9
• Calibrated Self–test
1
• Low Voltage Detect, Clock Monitor, and EPROM Parity Check Status
8
• Transducer Hermetically Sealed at Wafer Level for Superior Reliability
16 LEAD SOIC
CASE 475
• Robust Design, High Shocks Survivability
Typical Applications
• Vibration Monitoring and Recording
• Appliance Control
• Mechanical Bearing Monitoring
• Computer Hard Drive Protection
• Computer Mouse and Joysticks
• Virtual Reality Input Devices
• Sports Diagnostic Devices and Systems
SIMPLIFIED ACCELEROMETER FUNCTIONAL BLOCK DIAGRAM
VDD
G–CELL
SENSOR
VST
SELF–TEST
INTEGRATOR
GAIN
CONTROL LOGIC &
EPROM TRIM CIRCUITS
FILTER
OSCILLATOR
TEMP
COMP
VOUT
CLOCK GEN.
VSS
STATUS
Figure 1. Simplified Accelerometer Functional Block Diagram
REV 0
2–42
For www.motorola.com/semiconductors
More Information On This Product,
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MMA2201D
MAXIMUM RATINGS (Maximum ratings are the limits to which the device can be exposed without causing permanent damage.)
Symbol
Value
Unit
Powered Acceleration (all axes)
Rating
Gpd
500
g
Unpowered Acceleration (all axes)
Gupd
2000
g
Supply Voltage
VDD
–0.3 to +7.0
V
Ddrop
1.2
m
Tstg
– 40 to +105
°C
Drop Test(1)
Storage Temperature Range
NOTES:
1. Dropped onto concrete surface from any axis.
Freescale Semiconductor, Inc...
ELECTRO STATIC DISCHARGE (ESD)
WARNING: This device is sensitive to electrostatic
discharge.
Although the Motorola accelerometers contain internal
2kV ESD protection circuitry, extra precaution must be taken
by the user to protect the chip from ESD. A charge of over
Motorola Sensor Device Data
2000 volts can accumulate on the human body or associated
test equipment. A charge of this magnitude can alter the performance or cause failure of the chip. When handling the
accelerometer, proper ESD precautions should be followed
to avoid exposing the device to discharges which may be
detrimental to its performance.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
2–43
Freescale Semiconductor, Inc.
MMA2201D
OPERATING CHARACTERISTICS
(Unless otherwise noted: –40°C
v TA v +85°C, 4.75 v VDD v 5.25, Acceleration = 0g, Loaded output(1))
Characteristic
Symbol
Min
Typ
Max
Unit
VDD
IDD
TA
gFS
4.75
4.0
40
—
5.00
5.0
—
38
5.25
6.0
+85
—
V
mA
°C
g
VOFF
VOFF,V
S
SV
f –3dB
NLOUT
2.3
0.44 VDD
47.5
9.3
360
1.0
2.5
0.50 VDD
50
10
400
—
2.7
0.56 VDD
52.5
10.7
440
+1.0
V
V
mV/g
mV/g/V
Hz
% FSO
nRMS
nPSD
nCLK
—
—
—
—
110
2.0
2.8
—
—
mVrms
µV/(Hz1/2)
mVpk
Self–Test
Output Response
Input Low
Input High
Input Loading(7)
Response Time(8)
gST
VIL
VIH
IIN
tST
10
VSS
0.7 x VDD
30
—
14
0.3 x VDD
VDD
300
10
g
V
V
µA
ms
Status(12)(13)
Output Low (Iload = 100 µA)
Output High (Iload = 100 µA)
VOL
VOH
—
VDD .8
—
—
0.4
—
V
V
Minimum Supply Voltage (LVD Trip)
VLVD
2.7
3.25
4.0
V
fmin
150
—
400
kHz
Output Stage Performance
Electrical Saturation Recovery Time(9)
Full Scale Output Range (IOUT = 200 µA)
Capacitive Load Drive(10)
Output Impedance
tDELAY
VFSO
CL
ZO
—
0.3
—
—
0.2
—
—
300
—
VDD 0.3
100
—
ms
V
pF
Ω
Mechanical Characteristics
Transverse Sensitivity(11)
Package Resonance
VZX,YX
fPKG
—
—
—
10
5.0
—
% FSO
kHz
Operating Range(2)
Supply Voltage(3)
Supply Current
Operating Temperature Range
Acceleration Range
Freescale Semiconductor, Inc...
Output Signal
Zero g (VDD = 5.0 V)(4)
Zero g
Sensitivity (TA = 25°C, VDD = 5.0 V)(5)
Sensitivity
Bandwidth Response
Nonlinearity
Noise
RMS (.01–1 kHz)
Power Spectral Density
Clock Noise (without RC load on output)(6)
Clock Monitor Fail Detection Frequency
*
*
*
12
—
—
110
2.0
*
*
*
*
NOTES:
1. For a loaded output the measurements are observed after an RC filter consisting of a 1 kΩ resistor and a 0.01 µF capacitor to ground.
2. These limits define the range of operation for which the part will meet specification.
3. Within the supply range of 4.75 and 5.25 volts, the device operates as a fully calibrated linear accelerometer. Beyond these supply limits
the device may operate as a linear device but is not guaranteed to be in calibration.
4. The device can measure both + and acceleration. With no input acceleration the output is at midsupply. For positive acceleration the output
will increase above VDD/2 and for negative acceleration the output will decrease below VDD/2.
5. The device is calibrated at 20g.
6. At clock frequency
70 kHz.
7. The digital input pin has an internal pull–down current source to prevent inadvertent self test initiation due to external board level leakages.
8. Time for the output to reach 90% of its final value after a self–test is initiated.
9. Time for amplifiers to recover after an acceleration signal causing them to saturate.
10. Preserves phase margin (60°) to guarantee output amplifier stability.
11. A measure of the device’s ability to reject an acceleration applied 90° from the true axis of sensitivity.
12. The Status pin output is not valid following power–up until at least one rising edge has been applied to the self–test pin. The Status pin is
high whenever the self–test input is high.
13. The Status pin output latches high if a Low Voltage Detection or Clock Frequency failure occurs, or the EPROM parity changes to odd. The
Status pin can be reset by a rising edge on self–test, unless a fault condition continues to exist.
*
^
2–44
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
Freescale Semiconductor, Inc...
PRINCIPLE OF OPERATION
The Motorola accelerometer is a surface–micromachined
integrated–circuit accelerometer.
The device consists of a surface micromachined capacitive sensing cell (g–cell) and a CMOS signal conditioning
ASIC contained in a single integrated circuit package. The
sensing element is sealed hermetically at the wafer level
using a bulk micromachined “cap’’ wafer.
The g–cell is a mechanical structure formed from semiconductor materials (polysilicon) using semiconductor processes (masking and etching). It can be modeled as two
stationary plates with a moveable plate in–between. The
center plate can be deflected from its rest position by subjecting the system to an acceleration (Figure 2).
When the center plate deflects, the distance from it to one
fixed plate will increase by the same amount that the distance to the other plate decreases. The change in distance is
a measure of acceleration.
The g–cell plates form two back–to–back capacitors
(Figure 3). As the center plate moves with acceleration, the
distance between the plates changes and each capacitor’s
value will change, (C = Aε/D). Where A is the area of the
plate, ε is the dielectric constant, and D is the distance
between the plates.
The CMOS ASIC uses switched capacitor techniques to
measure the g–cell capacitors and extract the acceleration
data from the difference between the two capacitors. The
ASIC also signal conditions and filters (switched capacitor)
the signal, providing a high level output voltage that is ratiometric and proportional to acceleration.
Acceleration
Figure 2. Transducer
Physical Model
Self–Test
The sensor provides a self–test feature that allows the
verification of the mechanical and electrical integrity of the
accelerometer at any time before or after installation. This
feature is critical in applications such as automotive airbag
systems where system integrity must be ensured over the life
of the vehicle. A fourth “plate’’ is used in the g–cell as a self–
test plate. When the user applies a logic high input to the
self–test pin, a calibrated potential is applied across the
self–test plate and the moveable plate. The resulting electrostatic force (Fe = 1/2 AV2/d2) causes the center plate to
deflect. The resultant deflection is measured by the accelerometer’s control ASIC and a proportional output voltage
results. This procedure assures that both the mechanical
(g–cell) and electronic sections of the accelerometer are
functioning.
Ratiometricity
Ratiometricity simply means that the output offset voltage
and sensitivity will scale linearly with applied supply voltage.
That is, as you increase supply voltage the sensitivity and
offset increase linearly; as supply voltage decreases, offset
and sensitivity decrease linearly. This is a key feature when
interfacing to a microcontroller or an A/D converter because
it provides system level cancellation of supply induced errors
in the analog to digital conversion process.
Status
Motorola accelerometers include fault detection circuitry
and a fault latch. The Status pin is an output from the fault
latch, OR’d with self–test, and is set high whenever one (or
more) of the following events occur:
• Supply voltage falls below the Low Voltage Detect (LVD)
voltage threshold
• Clock oscillator falls below the clock monitor minimum
frequency
• Parity of the EPROM bits becomes odd in number.
The fault latch can be reset by a rising edge on the self–
test input pin, unless one (or more) of the fault conditions
continues to exist.
BASIC CONNECTIONS
Figure 3. Equivalent
Circuit Model
Pinout Description
SPECIAL FEATURES
N/C
Filtering
The Motorola accelerometers contain an onboard 4–pole
switched capacitor filter. A Bessel implementation is used
because it provides a maximally flat delay response (linear
phase) thus preserving pulse shape integrity. Because the filter is realized using switched capacitor techniques, there is
no requirement for external passive components (resistors
and capacitors) to set the cut–off frequency.
N/C
N/C
Motorola Sensor Device Data
MMA2201D
ST
VOUT
N/C
VSS
VDD
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Information On This Product,
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1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
N/C
9
N/C
N/C
N/C
N/C
N/C
N/C
N/C
2–45
Freescale Semiconductor, Inc.
PCB Layout
Pin Name
1 thru 3
—
No internal connection. Leave
unconnected.
4
ST
Logic input pin used to initiate
self–test.
5
VOUT
6
—
Description
Output voltage of the accelerometer.
No internal connection. Leave
unconnected.
7
VSS
The power supply ground.
8
VDD
The power supply input.
9 thru 13
Trim pins
14 thru 16
—
VDD
No internal connection. Leave
unconnected.
LOGIC
INPUT
6
4 ST
8 VDD
C1
0.1 µF
7 VSS
VOUT
5
STATUS
R1
1 kΩ
OUTPUT
SIGNAL
C2
0.01 µF
Figure 4. SOIC Accelerometer with Recommended
Connection Diagram
2–46
P1
ST
VOUT
VSS
VDD
P0
A/D IN
R
1 kΩ
C 0.01 µF
C 0.1 µF
VRH
C
Used for factory trim. Leave
unconnected.
MMA2201D
STATUS
ACCELEROMETER
Pin No.
MICROCONTROLLER
Freescale Semiconductor, Inc...
MMA2201D
VSS
C 0.1 µF
VDD
0.1 µF
POWER SUPPLY
Figure 5. Recommend PCB Layout for Interfacing
Accelerometer to Microcontroller
NOTES:
• Use a 0.1 µF capacitor on VDD to decouple the power
source.
• Physical coupling distance of the accelerometer to the
microcontroller should be minimal.
• Place a ground plane beneath the accelerometer to reduce
noise, the ground plane should be attached to all of the
open ended terminals shown in Figure 4.
• Use an RC filter of 1 kΩ and 0.01 µF on the output of the
accelerometer to minimize clock noise (from the switched
capacitor filter circuit).
• PCB layout of power and ground should not couple power
supply noise.
• Accelerometer and microcontroller should not be a high
current path.
• A/D sampling rate and any external power supply switching
frequency should be selected such that they do not interfere with the internal accelerometer sampling frequency.
This will prevent aliasing errors.
For www.motorola.com/semiconductors
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MMA2201D
Positive Acceleration Sensing Direction
N/C
–X
N/C
N/C
AXIS
ORIENTATION
(ACCELERATION
FORCE
VECTOR)
SELF TEST
XOUT
N/C
+X
VSS
VDD
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
N/C
N/C
N/C
N/C
N/C
N/C
N/C
N/C
16–Pin SOIC Package
Freescale Semiconductor, Inc...
N/C pins are recommended to be left FLOATING
8 7
6
5
4
3
2
1
Direction of Earth’s gravity field.*
9 10 11 12 13 14 15 16
* When positioned as shown, the Earth’s gravity will result in a positive 1g output
ORDERING INFORMATION
Device
MMA2201D
Temperature Range
*40 to +85°C
Motorola Sensor Device Data
Case No.
Case 475–01
Package
SOIC–16
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Information On This Product,
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2–47
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
Surface Mount
Micromachined Accelerometer
The MMA series of silicon capacitive, micromachined accelerometers
features signal conditioning, a 4–pole low pass filter and temperature
compensation. Zero–g offset full scale span and filter cut–off are factory set and
require no external devices. A full system self–test capability verifies system
functionality.
Features
• Integral Signal Conditioning
MMA2202D
MMA2202D: X AXIS SENSITIVITY
MICROMACHINED
ACCELEROMETER
± 50g
Freescale Semiconductor, Inc...
• Linear Output
• Ratiometric Performance
• 4th Order Bessel Filter Preserves Pulse Shape Integrity
16
• Calibrated Self–test
• Low Voltage Detect, Clock Monitor, and EPROM Parity Check Status
9
1
• Transducer Hermetically Sealed at Wafer Level for Superior Reliability
8
• Robust Design, High Shocks Survivability
16 LEAD SOIC
CASE 475
Typical Applications
• Vibration Monitoring and Recording
• Impact Monitoring
• Appliance Control
Pin Assignment
• Mechanical Bearing Monitoring
• Computer Hard Drive Protection
N/C
• Computer Mouse and Joysticks
N/C
• Virtual Reality Input Devices
N/C
ST
• Sports Diagnostic Devices and Systems
1
2
3
4
5
6
7
8
VOUT
STATUS
VSS
VDD
16
15
14
13
12
11
10
N/C
9
N/C
N/C
N/C
N/C
N/C
N/C
N/C
SIMPLIFIED ACCELEROMETER FUNCTIONAL BLOCK DIAGRAM
VDD
G–CELL
SENSOR
ST
SELF–TEST
INTEGRATOR
GAIN
CONTROL LOGIC &
EPROM TRIM CIRCUITS
FILTER
OSCILLATOR
TEMP
COMP
VOUT
CLOCK GEN.
VSS
STATUS
Figure 1. Simplified Accelerometer Functional Block Diagram
REV 0
2–48
For www.motorola.com/semiconductors
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MMA2202D
MAXIMUM RATINGS (Maximum ratings are the limits to which the device can be exposed without causing permanent damage.)
Symbol
Value
Unit
Powered Acceleration (all axes)
Rating
Gpd
500
g
Unpowered Acceleration (all axes)
Gupd
2000
g
Supply Voltage
VDD
–0.3 to +7.0
V
Ddrop
1.2
m
Tstg
– 40 to +105
°C
Drop Test(1)
Storage Temperature Range
NOTES:
1. Dropped onto concrete surface from any axis.
Freescale Semiconductor, Inc...
ELECTRO STATIC DISCHARGE (ESD)
WARNING: This device is sensitive to electrostatic
discharge.
Although the Motorola accelerometers contain internal
2kV ESD protection circuitry, extra precaution must be taken
by the user to protect the chip from ESD. A charge of over
Motorola Sensor Device Data
2000 volts can accumulate on the human body or associated
test equipment. A charge of this magnitude can alter the performance or cause failure of the chip. When handling the
accelerometer, proper ESD precautions should be followed
to avoid exposing the device to discharges which may be
detrimental to its performance.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
2–49
Freescale Semiconductor, Inc.
MMA2202D
OPERATING CHARACTERISTICS
(Unless otherwise noted: –40°C
v TA v +85°C, 4.75 v VDD v 5.25, Acceleration = 0g, Loaded output(1))
Characteristic
Symbol
Min
Typ
Max
Unit
VDD
IDD
TA
gFS
4.75
4.0
40
—
5.00
5.0
—
47
5.25
6.0
+85
—
V
mA
°C
g
VOFF
VOFF,V
S
SV
f –3dB
NLOUT
2.3
0.44 VDD
37
7.4
360
1.0
2.5
0.50 VDD
40
8
400
—
2.7
0.56 VDD
43
8.6
440
+1.0
V
V
mV/g
mV/g/V
Hz
% FSO
nRMS
nPSD
nCLK
—
—
—
—
110
2.0
2.8
—
—
mVrms
µV/(Hz1/2)
mVpk
Self–Test
Output Response
Input Low
Input High
Input Loading(7)
Response Time(8)
gST
VIL
VIH
IIN
tST
10
VSS
0.7 x VDD
30
—
14
0.3 x VDD
VDD
300
10
g
V
V
µA
ms
Status(12)(13)
Output Low (Iload = 100 µA)
Output High (Iload = 100 µA)
VOL
VOH
—
VDD .8
—
—
0.4
—
V
V
Minimum Supply Voltage (LVD Trip)
VLVD
2.7
3.25
4.0
V
fmin
150
—
400
kHz
Output Stage Performance
Electrical Saturation Recovery Time(9)
Full Scale Output Range (IOUT = 200 µA)
Capacitive Load Drive(10)
Output Impedance
tDELAY
VFSO
CL
ZO
—
0.3
—
—
0.2
—
—
300
—
VDD 0.3
100
—
ms
V
pF
Ω
Mechanical Characteristics
Transverse Sensitivity(11)
Package Resonance
VZX,YX
fPKG
—
—
—
10
5.0
—
% FSO
kHz
Operating Range(2)
Supply Voltage(3)
Supply Current
Operating Temperature Range
Acceleration Range
Freescale Semiconductor, Inc...
Output Signal
Zero g (VDD = 5.0 V)(4)
Zero g
Sensitivity (TA = 25°C, VDD = 5.0 V)(5)
Sensitivity
Bandwidth Response
Nonlinearity
Noise
RMS (.01–1 kHz)
Power Spectral Density
Clock Noise (without RC load on output)(6)
Clock Monitor Fail Detection Frequency
*
*
*
12
—
—
110
2.0
*
*
*
*
NOTES:
1. For a loaded output the measurements are observed after an RC filter consisting of a 1 kΩ resistor and a 0.01 µF capacitor to ground.
2. These limits define the range of operation for which the part will meet specification.
3. Within the supply range of 4.75 and 5.25 volts, the device operates as a fully calibrated linear accelerometer. Beyond these supply limits
the device may operate as a linear device but is not guaranteed to be in calibration.
4. The device can measure both + and acceleration. With no input acceleration the output is at midsupply. For positive acceleration the output
will increase above VDD/2 and for negative acceleration the output will decrease below VDD/2.
5. The device is calibrated at 20g.
6. At clock frequency
70 kHz.
7. The digital input pin has an internal pull–down current source to prevent inadvertent self test initiation due to external board level leakages.
8. Time for the output to reach 90% of its final value after a self–test is initiated.
9. Time for amplifiers to recover after an acceleration signal causing them to saturate.
10. Preserves phase margin (60°) to guarantee output amplifier stability.
11. A measure of the device’s ability to reject an acceleration applied 90° from the true axis of sensitivity.
12. The Status pin output is not valid following power–up until at least one rising edge has been applied to the self–test pin. The Status pin is
high whenever the self–test input is high.
13. The Status pin output latches high if a Low Voltage Detection or Clock Frequency failure occurs, or the EPROM parity changes to odd. The
Status pin can be reset by a rising edge on self–test, unless a fault condition continues to exist.
*
^
2–50
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
Freescale Semiconductor, Inc...
PRINCIPLE OF OPERATION
The Motorola accelerometer is a surface–micromachined
integrated–circuit accelerometer.
The device consists of a surface micromachined capacitive sensing cell (g–cell) and a CMOS signal conditioning
ASIC contained in a single integrated circuit package. The
sensing element is sealed hermetically at the wafer level
using a bulk micromachined “cap’’ wafer.
The g–cell is a mechanical structure formed from semiconductor materials (polysilicon) using semiconductor processes (masking and etching). It can be modeled as two
stationary plates with a moveable plate in–between. The
center plate can be deflected from its rest position by subjecting the system to an acceleration (Figure 2).
When the center plate deflects, the distance from it to one
fixed plate will increase by the same amount that the distance to the other plate decreases. The change in distance is
a measure of acceleration.
The g–cell plates form two back–to–back capacitors
(Figure 3). As the center plate moves with acceleration, the
distance between the plates changes and each capacitor’s
value will change, (C = Aε/D). Where A is the area of the
plate, ε is the dielectric constant, and D is the distance
between the plates.
The CMOS ASIC uses switched capacitor techniques to
measure the g–cell capacitors and extract the acceleration
data from the difference between the two capacitors. The
ASIC also signal conditions and filters (switched capacitor)
the signal, providing a high level output voltage that is ratiometric and proportional to acceleration.
Acceleration
Figure 2. Transducer
Physical Model
Self–Test
The sensor provides a self–test feature that allows the
verification of the mechanical and electrical integrity of the
accelerometer at any time before or after installation. This
feature is critical in applications such as automotive airbag
systems where system integrity must be ensured over the life
of the vehicle. A fourth “plate’’ is used in the g–cell as a self–
test plate. When the user applies a logic high input to the
self–test pin, a calibrated potential is applied across the
self–test plate and the moveable plate. The resulting electrostatic force (Fe = 1/2 AV2/d2) causes the center plate to
deflect. The resultant deflection is measured by the accelerometer’s control ASIC and a proportional output voltage
results. This procedure assures that both the mechanical
(g–cell) and electronic sections of the accelerometer are
functioning.
Ratiometricity
Ratiometricity simply means that the output offset voltage
and sensitivity will scale linearly with applied supply voltage.
That is, as you increase supply voltage the sensitivity and
offset increase linearly; as supply voltage decreases, offset
and sensitivity decrease linearly. This is a key feature when
interfacing to a microcontroller or an A/D converter because
it provides system level cancellation of supply induced errors
in the analog to digital conversion process.
Status
Motorola accelerometers include fault detection circuitry
and a fault latch. The Status pin is an output from the fault
latch, OR’d with self–test, and is set high whenever one (or
more) of the following events occur:
• Supply voltage falls below the Low Voltage Detect (LVD)
voltage threshold
• Clock oscillator falls below the clock monitor minimum
frequency
• Parity of the EPROM bits becomes odd in number.
The fault latch can be reset by a rising edge on the self–
test input pin, unless one (or more) of the fault conditions
continues to exist.
BASIC CONNECTIONS
Figure 3. Equivalent
Circuit Model
Pinout Description
SPECIAL FEATURES
N/C
Filtering
The Motorola accelerometers contain an onboard 4–pole
switched capacitor filter. A Bessel implementation is used
because it provides a maximally flat delay response (linear
phase) thus preserving pulse shape integrity. Because the filter is realized using switched capacitor techniques, there is
no requirement for external passive components (resistors
and capacitors) to set the cut–off frequency.
N/C
N/C
Motorola Sensor Device Data
MMA2202D
ST
VOUT
STATUS
VSS
VDD
www.motorola.com/semiconductors
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Information On This Product,
Go to: www.freescale.com
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
N/C
9
N/C
N/C
N/C
N/C
N/C
N/C
N/C
2–51
Freescale Semiconductor, Inc.
PCB Layout
Pin Name
1 thru 3
—
No internal connection. Leave
unconnected.
4
ST
Logic input pin used to initiate
self–test.
5
VOUT
6
STATUS
7
8
VSS
VDD
9 thru 13
Trim pins
14 thru 16
—
VDD
Description
Output voltage of the accelerometer.
Logic output pin to indicate fault.
The power supply ground.
The power supply input.
8 VDD
7 VSS
VOUT
VSS
VDD
P0
A/D IN
R
1 kΩ
C 0.01 µF
C 0.1 µF
VRH
VOUT
6
5
VSS
C 0.1 µF
VDD
0.1 µF
POWER SUPPLY
Figure 5. Recommend PCB Layout for Interfacing
Accelerometer to Microcontroller
STATUS
R1
1 kΩ
OUTPUT
SIGNAL
C2
0.01 µF
Figure 4. SOIC Accelerometer with Recommended
Connection Diagram
2–52
ST
C
No internal connection. Leave
unconnected.
4 ST
C1
0.1 µF
P1
Used for factory trim. Leave
unconnected.
MMA2202D
LOGIC
INPUT
STATUS
ACCELEROMETER
Pin No.
MICROCONTROLLER
Freescale Semiconductor, Inc...
MMA2202D
NOTES:
• Use a 0.1 µF capacitor on VDD to decouple the power
source.
• Physical coupling distance of the accelerometer to the
microcontroller should be minimal.
• Place a ground plane beneath the accelerometer to reduce
noise, the ground plane should be attached to all of the
open ended terminals shown in Figure 4.
• Use an RC filter of 1 kΩ and 0.01 µF on the output of the
accelerometer to minimize clock noise (from the switched
capacitor filter circuit).
• PCB layout of power and ground should not couple power
supply noise.
• Accelerometer and microcontroller should not be a high
current path.
• A/D sampling rate and any external power supply switching
frequency should be selected such that they do not interfere with the internal accelerometer sampling frequency.
This will prevent aliasing errors.
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MMA2202D
Positive Acceleration Sensing Direction
1
2
3
4
5
6
7
8
–X
16
15
14
13
12
11
10
+X
9
16–Pin SOIC Package
Freescale Semiconductor, Inc...
N/C pins are recommended to be left FLOATING
Top View
8 7
6
5
4
3
2
1
Direction of Earth’s gravity field.*
9 10 11 12 13 14 15 16
Front View
Side View
* When positioned as shown, the Earth’s gravity will result in a positive 1g output
ORDERING INFORMATION
Device
MMA2202D
Temperature Range
*40 to +85°C
Case No.
Package
Case 475–01
SOIC–16
MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS
Surface mount board layout is a critical portion of the total
design. The footprint for the surface mount packages must
be the correct size to ensure proper solder connection interface between the board and the package. With the correct
Motorola Sensor Device Data
footprint, the packages will self–align when subjected to a
solder reflow process. It is always recommended to design
boards with a solder mask layer to avoid bridging and shorting between solder pads.
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MMA2202D
Freescale Semiconductor, Inc.
0.380 in.
9.65 mm
0.050 in.
1.27 mm
Freescale Semiconductor, Inc...
0.024 in.
0.610 mm
0.080 in.
2.03 mm
Figure 6. Footprint SOIC–16 (Case 475–01)
2–54
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MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
Surface Mount
Micromachined Accelerometer
The MMA series of silicon capacitive, micromachined accelerometers
features signal conditioning, a 4–pole low pass filter and temperature
compensation. Zero–g offset full scale span and filter cut–off are factory set and
require no external devices. A full system self–test capability verifies system
functionality.
Features
MMA3201D
MMA3201D: X–Y AXIS SENSITIVITY
MICROMACHINED
ACCELEROMETER
± 40g
• Integral Signal Conditioning
Freescale Semiconductor, Inc...
• Linear Output
• Ratiometric Performance
20
• 4th Order Bessel Filter Preserves Pulse Shape Integrity
• Calibrated Self–test
11
1
• Low Voltage Detect, Clock Monitor, and EPROM Parity Check Status
• Transducer Hermetically Sealed at Wafer Level for Superior Reliability
10
• Robust Design, High Shocks Survivability
20 LEAD SOIC
CASE 475A
Typical Applications
• Vibration Monitoring and Recording
• Impact Monitoring
• Appliance Control
Pin Assignment
• Mechanical Bearing Monitoring
• Computer Hard Drive Protection
N/C
• Computer Mouse and Joysticks
N/C
N/C
• Virtual Reality Input Devices
N/C
ST
XOUT
• Sports Diagnostic Devices and Systems
STATUS
VSS
VDD
AVDD
1
2
3
4
5
6
7
8
20
19
18
17
16
15
14
N/C
13
N/C
9
10
12
N/C
YOUT
11
N/C
N/C
N/C
N/C
N/C
N/C
SIMPLIFIED ACCELEROMETER FUNCTIONAL BLOCK DIAGRAM
AVDD
VDD
G–CELL
SENSOR
INTEGRATOR
GAIN
FILTER
TEMP
COMP
XOUT
YOUT
ST
SELF–TEST
CONTROL LOGIC &
EPROM TRIM CIRCUITS
OSCILLATOR
CLOCK GEN.
VSS
STATUS
Figure 1. Simplified Accelerometer Functional Block Diagram
REV 0
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MMA3201D
MAXIMUM RATINGS (Maximum ratings are the limits to which the device can be exposed without causing permanent damage.)
Rating
Symbol
Value
Unit
Powered Acceleration (all axes)
Gpd
$200
Unpowered Acceleration (all axes)
Gupd
2000
g
Supply Voltage
VDD
–0.3 to +7.0
V
Ddrop
1.2
m
Tstg
– 40 to +105
°C
Drop Test(1)
Storage Temperature Range
g
NOTES:
1. Dropped onto concrete surface from any axis.
Freescale Semiconductor, Inc...
ELECTRO STATIC DISCHARGE (ESD)
WARNING: This device is sensitive to electrostatic
discharge.
Although the Motorola accelerometers contain internal
2kV ESD protection circuitry, extra precaution must be taken
by the user to protect the chip from ESD. A charge of over
2–56
2000 volts can accumulate on the human body or associated
test equipment. A charge of this magnitude can alter the performance or cause failure of the chip. When handling the accelerometer, proper ESD precautions should be followed to
avoid exposing the device to discharges which may be detrimental to its performance.
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MMA3201D
OPERATING CHARACTERISTICS
(Unless otherwise noted: –40°C
v TA v +85°C, 4.75 v VDD v 5.25, X and Y Channels, Acceleration = 0g, Loaded output(1))
Characteristic
Symbol
Min
Typ
Max
Unit
VDD
IDD
TA
gFS
4.75
6
40
—
5.00
8
—
45
5.25
10
+85
—
V
mA
°C
g
VOFF
VOFF,V
S
SV
f –3dB
NLOUT
2.2
0.44 VDD
45
9
360
1.0
2.5
0.50 VDD
50
10
400
—
2.8
0.56 VDD
55
11
440
+1.0
V
V
mV/g
mV/g/V
Hz
% FSO
nRMS
nPSD
nCLK
—
—
—
—
110
2.0
2.8
—
—
mVrms
µV/(Hz1/2)
mVpk
Self–Test
Output Response
Input Low
Input High
Input Loading(7)
Response Time(8)
gST
VIL
VIH
IIN
tST
9.6
VSS
0.7 x VDD
30
—
14.4
0.3 x VDD
VDD
300
—
g
V
V
µA
ms
Status(12)(13)
Output Low (Iload = 100 µA)
Output High (Iload = 100 µA)
VOL
VOH
—
VDD .8
—
—
0.4
—
V
V
Minimum Supply Voltage (LVD Trip)
VLVD
2.7
3.25
4.0
V
fmin
50
—
260
kHz
Output Stage Performance
Electrical Saturation Recovery Time(9)
Full Scale Output Range (IOUT = 200 µA)
Capacitive Load Drive(10)
Output Impedance
tDELAY
VFSO
CL
ZO
—
0.3
—
—
0.2
—
—
300
—
VDD 0.3
100
—
ms
V
pF
Ω
Mechanical Characteristics
Transverse Sensitivity(11)
Package Resonance
VZX,YX
fPKG
—
—
—
10
5.0
—
% FSO
kHz
Operating Range(2)
Supply Voltage(3)
Supply Current
Operating Temperature Range
Acceleration Range
Freescale Semiconductor, Inc...
Output Signal
Zero g (VDD = 5.0 V)(4)
Zero g
Sensitivity (TA = 25°C, VDD = 5.0 V)(5)
Sensitivity
Bandwidth Response
Nonlinearity
Noise
RMS (.01–1 kHz)
Power Spectral Density
Clock Noise (without RC load on output)(6)
Clock Monitor Fail Detection Frequency
*
*
*
*
12
—
—
110
2.0
*
*
*
NOTES:
1. For a loaded output the measurements are observed after an RC filter consisting of a 1 kΩ resistor and a 0.01 µF capacitor to ground.
2. These limits define the range of operation for which the part will meet specification.
3. Within the supply range of 4.75 and 5.25 volts, the device operates as a fully calibrated linear accelerometer. Beyond these supply limits
the device may operate as a linear device but is not guaranteed to be in calibration.
4. The device can measure both + and acceleration. With no input acceleration the output is at midsupply. For positive acceleration the output
will increase above VDD/2 and for negative acceleration the output will decrease below VDD/2.
5. The device is calibrated at 20g.
6. At clock frequency
70 kHz.
7. The digital input pin has an internal pull–down current source to prevent inadvertent self test initiation due to external board level leakages.
8. Time for the output to reach 90% of its final value after a self–test is initiated.
9. Time for amplifiers to recover after an acceleration signal causing them to saturate.
10. Preserves phase margin (60°) to guarantee output amplifier stability.
11. A measure of the device’s ability to reject an acceleration applied 90° from the true axis of sensitivity.
12. The Status pin output is not valid following power–up until at least one rising edge has been applied to the self–test pin. The Status pin is
high whenever the self–test input is high.
13. The Status pin output latches high if a Low Voltage Detection or Clock Frequency failure occurs, or the EPROM parity changes to odd. The
Status pin can be reset by a rising edge on self–test, unless a fault condition continues to exist.
*
^
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MMA3201D
Freescale Semiconductor, Inc...
PRINCIPLE OF OPERATION
The Motorola accelerometer is a surface–micromachined
integrated–circuit accelerometer.
The device consists of a surface micromachined capacitive sensing cell (g–cell) and a CMOS signal conditioning
ASIC contained in a single integrated circuit package. The
sensing element is sealed hermetically at the wafer level using a bulk micromachined “cap’’ wafer.
The g–cell is a mechanical structure formed from semiconductor materials (polysilicon) using semiconductor processes (masking and etching). It can be modeled as two
stationary plates with a moveable plate in–between. The
center plate can be deflected from its rest position by subjecting the system to an acceleration (Figure 2).
When the center plate deflects, the distance from it to one
fixed plate will increase by the same amount that the distance to the other plate decreases. The change in distance is
a measure of acceleration.
The g–cell plates form two back–to–back capacitors (Figure 3). As the center plate moves with acceleration, the distance between the plates changes and each capacitor’s
value will change, (C = Aε/D). Where A is the area of the
plate, ε is the dielectric constant, and D is the distance between the plates.
The CMOS ASIC uses switched capacitor techniques to
measure the g–cell capacitors and extract the acceleration
data from the difference between the two capacitors. The
ASIC also signal conditions and filters (switched capacitor)
the signal, providing a high level output voltage that is ratiometric and proportional to acceleration.
Acceleration
Figure 2. Transducer
Physical Model
Self–Test
The sensor provides a self–test feature that allows the verification of the mechanical and electrical integrity of the accelerometer at any time before or after installation. This
feature is critical in applications such as automotive airbag
systems where system integrity must be ensured over the life
of the vehicle. A fourth “plate’’ is used in the g–cell as a self–
test plate. When the user applies a logic high input to the
self–test pin, a calibrated potential is applied across the
self–test plate and the moveable plate. The resulting electrostatic force (Fe = 1/2 AV2/d2) causes the center plate to
deflect. The resultant deflection is measured by the accelerometer’s control ASIC and a proportional output voltage results. This procedure assures that both the mechanical
(g–cell) and electronic sections of the accelerometer are
functioning.
Ratiometricity
Ratiometricity simply means that the output offset voltage
and sensitivity will scale linearly with applied supply voltage.
That is, as you increase supply voltage the sensitivity and
offset increase linearly; as supply voltage decreases, offset
and sensitivity decrease linearly. This is a key feature when
interfacing to a microcontroller or an A/D converter because
it provides system level cancellation of supply induced errors
in the analog to digital conversion process.
Status
Motorola accelerometers include fault detection circuitry
and a fault latch. The Status pin is an output from the fault
latch, OR’d with self–test, and is set high whenever one (or
more) of the following events occur:
• Supply voltage falls below the Low Voltage Detect (LVD)
voltage threshold
• Clock oscillator falls below the clock monitor minimum
frequency
• Parity of the EPROM bits becomes odd in number.
The fault latch can be reset by a rising edge on the self–
test input pin, unless one (or more) of the fault conditions
continues to exist.
BASIC CONNECTIONS
Figure 3. Equivalent
Circuit Model
Pinout Description
N/C
N/C
SPECIAL FEATURES
N/C
Filtering
The Motorola accelerometers contain an onboard 4–pole
switched capacitor filter. A Bessel implementation is used
because it provides a maximally flat delay response (linear
phase) thus preserving pulse shape integrity. Because the filter is realized using switched capacitor techniques, there is
no requirement for external passive components (resistors
and capacitors) to set the cut–off frequency.
N/C
ST
2–58
XOUT
STATUS
VSS
VDD
AVDD
1
2
3
4
5
6
7
8
20
19
18
17
16
15
14
9
10
12
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13
11
N/C
N/C
N/C
N/C
N/C
N/C
N/C
N/C
N/C
YOUT
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
1 thru 3
—
Redundant Vss. Leave unconnected.
4
—
No internal connection. Leave
unconnected.
ST
6
XOUT
7
STATUS
8
VSS
VDD
10
Logic input pin used to initiate
self–test.
Output voltage of the accelerometer.
X Direction.
Logic output pin to indicate fault.
YOUT
VSS
VDD
R
1 kΩ
R
1 kΩ
A/D IN
C 0.01 µF
A/D IN
C 0.01 µF
C 0.1 µF
VRH
C
11
12 thru 16
—
Used for factory trim. Leave
unconnected.
17 thru 20
—
No internal connection. Leave
unconnected.
Output voltage of the accelerometer.
Y Direction.
MMA3201D
7
STATUS
5 ST
9 VDD
C1
0.1 µF
P0
XOUT
Power supply input.
Power supply input (Analog).
LOGIC
INPUT
P1
ST
The power supply ground.
AVDD
YOUT
VDD
STATUS
ACCELEROMETER
Description
R1
1 kΩ
XOUT 6
10 AVDD
X OUTPUT
SIGNAL
C2
0.01 µF
8 VSS
YOUT 11
R2
1 kΩ
Y OUTPUT
SIGNAL
C3
0.01 µF
Figure 4. SOIC Accelerometer with Recommended
Connection Diagram
Motorola Sensor Device Data
MICROCONTROLLER
Pin
Name
9
Freescale Semiconductor, Inc...
PCB Layout
Pin No.
5
MMA3201D
VSS
C 0.1 µF
VDD
0.1 µF
POWER SUPPLY
Figure 5. Recommend PCB Layout for Interfacing
Accelerometer to Microcontroller
NOTES:
• Use a 0.1 µF capacitor on VDD to decouple the power
source.
• Physical coupling distance of the accelerometer to the microcontroller should be minimal.
• Place a ground plane beneath the accelerometer to reduce
noise, the ground plane should be attached to all of the
open ended terminals shown in Figure 4.
• Use an RC filter of 1 kΩ and 0.01 µF on the outputs of the
accelerometer to minimize clock noise (from the switched
capacitor filter circuit).
• PCB layout of power and ground should not couple power
supply noise.
• Accelerometer and microcontroller should not be a high
current path.
• A/D sampling rate and any external power supply switching
frequency should be selected such that they do not interfere with the internal accelerometer sampling frequency.
This will prevent aliasing errors.
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MMA3201D
Positive Acceleration Sensing Direction
–Y
Freescale Semiconductor, Inc...
–X
1
2
3
4
5
6
7
8
20
19
18
17
16
15
14
9
10
12
+X
13
11
+Y
20–Pin SOIC Package
N/C pins are recommended to be left FLOATING
Top View
10 9
8
7
6
5
4
3
2
1
Direction of Earth’s gravity field.*
11 12 13 14 15 16 17 18 19 20
Front View
Side View
* When positioned as shown, the Earth’s gravity will result in a positive 1g output
ORDERING INFORMATION
Device
MMA3201D
Temperature Range
*40 to +85°C
Case No.
Case 475A–01
Package
SOIC–20
MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS
2–60
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Surface mount board layout is a critical portion of the total
design. The footprint for the surface mount packages must
be the correct size to ensure proper solder connection interface between the board and the package. With the correct
Freescale Semiconductor, Inc...
0.380 in.
9.65 mm
MMA3201D
footprint, the packages will self–align when subjected to a
solder reflow process. It is always recommended to design
boards with a solder mask layer to avoid bridging and shorting between solder pads.
0.050 in.
1.27 mm
0.024 in.
0.610 mm
0.080 in.
2.03 mm
Figure 6. Footprint SOIC–20 (Case 475A–01)
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MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
Application Considerations for a
Switched Capacitor Accelerometer
AN1559
By Wayne Chavez
Freescale Semiconductor, Inc...
INTRODUCTION
Today’s low cost accelerometers are highly integrated
devices employing features such as signal conditioning,
filtering, offset compensation and self test. Combining this
feature set with economical plastic packaging requires that the
signal conditioning circuitry be as small as possible. One
approach is to implement sampled data system and switched
capacitor techniques as in the Motorola accelerometer.
As in all sampled data systems, precautions should be
taken to avoid signal aliasing errors. This application note
describes the Motorola accelerometer and how signal aliasing
can be introduced and more importantly minimized.
BACKGROUND
What is aliasing? Simply put, aliasing is the effect of
sampling a signal at an insufficient rate, thus creating another
signal at a frequency that is the difference between the original
signal frequency and the sampling rate. A graphical
explanation of aliasing is offered in Figure 1. In this figure, the
upper trace shows a 50 kHz sinusoidal waveform. Note that
when sampled at a 45 kHz rate, denoted by the boxes, a
sinusoidal pattern is formed. Lowpass filtering the sampled
points, to create a continuous signal, produces the 5 kHz
waveform shown in Figure 1 (lower). (The phase shift in the
lower figure is due to the low–pass filter).
Aliased signals, like the one in Figure 1 (lower) are often
unintentionally produced. Signal processing techniques are
well understood and sampling rates are chosen appropriately
(i.e. Nyquist criteria). However, the assumption is that the
signals of interest are well characterized and have a limited
bandwidth. This assumption is not always true, as in the case
of wideband noise.
Figure 1. Aliased Signals
REV 1
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DEMONSTRATION OF ALIASING
Under zero acceleration conditions a 100 mVrms signal was
injected onto the power supply line of 5.0 Vdc. The frequency
of the injected signal was tuned in to produce an alias in the
accelerometer’s passband. Figures 3 and 4 show the
difference in output when a high frequency signal is not and is
present on the VCC pin of the accelerometer.
1.0E+0
Vout
1.0E–1
1.0E–2
Vrms
Given the brief example on how aliasing can occur, how
does the accelerometer relate to aliasing? To answer this
question, a brief summary on how the accelerometer works is
in order.
The accelerometer is a two chip acceleration sensing
solution. The first chip is the acceleration transducer, termed
G–Cell, constructed by Micro Electro–Mechanical Systems
(MEMS) technology. The G–Cell is a two capacitor element
where the capacitors are in series and share a common center
plate. The deflection in the center plate changes the capacitance of each capacitor which is measured by the second chip,
termed control chip.
The control chip performs the signal conditioning (amplification, filtering, offset level shift) function in the system. This chip
measures the G–Cell output using switched capacitor techniques. By the nature of switched cap techniques, the system
is a sampled data system operating at sampling frequency fs.
The filter is switched capacitor, 4–pole Bessel implementation
with a –3 dB frequency of 400 Hz.
As a sampled data system, the accelerometer is not immune
to signal aliasing. However, given the accelerometer’s internal
filter, aliased signals will only appear in the output passband
when input signals are in the range | n• fs – fsignal | ≤ fBW. Where
fs is the sampling rate, fSignal is the input signal frequency, fBW
is the filter bandwidth and n is a positive integer to account for
all harmonics. The graphical representation is shown in Figure
2. The bounds can be extended beyond fBW to ensure an alias
free output.
SAMPLING
FREQUENCY
1.0E–3
1.0E–4
1.0E–5
1.0E–6
1.0E–7
41.0
41.2
41.4
41.6
FREQUENCY (kHz)
41.8
42.0
(a)
1.0E+0
VCC
1.0E–1
KEEP OUT ZONE
Vrms
1.0E–2
1.0E–3
SAMPLING
FREQUENCY
1.0E–4
1.0E–5
1.0E–6
n*fs – fBW
n*fs
n*fs + fBW
1.0E–7
41.0
Hz
41.2
Figure 2. Input signal frequency range where a signal
will be produced in the output passband.
41.4
41.6
FREQUENCY (kHz)
41.8
42.0
(b)
1.0E+0
ACCELEROMETER INPUT SIGNALS
The accelerometer is a ratiometric electro–mechanical
transducer. Therefore, the input signals to the device are the
acceleration and the input power source.
The acceleration input is limited in frequency bandwidth by
the geometry of the sensing, packaging, and mounting
structures that define the resonant frequency and response.
This response is in the range of 10 kHz, however, the practical
range is less than 600 Hz for most mechanical systems.
Therefore, aliasing an acceleration signal is unlikely.
The power input signal is ideally dc. However, depending on
the application system architecture, the power supply line can
be riddled with high frequency components. For example, dc
to dc converters can operate with switching frequencies
between 20 kHz and 200 kHz. This range encompasses the
sampling rate of the accelerometer and point to the power
source as the culprit in producing aliased signal.
Motorola Sensor Device Data
Vout
1.0E–1
1.0E–2
Vrms
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Freescale Semiconductor, Inc.
1.0E–3
1.0E–4
1.0E–5
1.0E–6
0
200
400
600
FREQUENCY (Hz)
800
1000
(c)
Figure 3. Normal Waveforms
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Points to note:
1.0E+0
1.0E–1
• Under clean dc bias, Vout and VCC, Figures 3a and 3b have
a signal component at the sampling rate. This is due to
switched capacitor currents coupling through finite power
supply source impedances and PCB paracitics.
Vout
INJECTED SIGNAL
FREQUENCY
Vrms
1.0E–2
SAMPLING
FREQUENCY
1.0E–3
• The low frequency output spectrum, Figure 3c, displays the
internal lowpass filter characteristics. (The filter and sampling characteristics are sometimes useful in system debugging.)
1.0E–4
1.0E–5
1.0E–6
41.0
41.2
41.4
41.6
FREQUENCY (kHz)
41.8
42.0
• As a result of sampling, the output waveform of Figure 4c
is produced where the injected high frequency signal has
now produced a signal in the passband.
1.0E+0
VCC
1.0E–1
INJECTED SIGNAL
FREQUENCY
Vrms
1.0E–2
• Harmonics of the aliased signal in the pass band are also
shown in Figure 4c.
1.0E–3
• Aliased signals in the passband will be amplified versions
of the injected signals. This is due to the signal conditioning
circuitry in the accelerometer that includes gain.
SAMPLING
FREQUENCY
1.0E–4
1.0E–5
ALIASING AVOIDANCE KEYS
1.0E–6
1.0E–7
41.0
41.2
41.4
41.6
FREQUENCY (kHz)
41.8
42.0
1.0E+0
Vout
1.0E–1
1.0E–2
• Proper bias decoupling will aid in noise reduction from other sources. With dense surface mount PCB assemblies, it
is often difficult to place and route decoupling components.
However, the accelerometer is not like a typical logic device. A little extra effort on decoupling goes a long way.
1.0E–3
1.0E–4
1.0E–5
1.0E–6
0
200
400
600
FREQUENCY (Hz)
800
(c)
Figure 4. Aliasing Comparison
2–64
• Use a linear regulated power source when feasible. Linear
regulators have excellent power supply rejection offering a
stable dc source.
• If using a switching power supply, ensure that the switching
frequency is not close to the accelerometer sampling frequency or its harmonics. Noting that the accelerometer will
gain the aliasing signal, it is desirable to keep frequencies
at least 4 kHz away from the sampling frequency and its
harmonics. 4 kHz is one decade from the –3 dB frequency,
therefore any signals will be sufficiently attenuated by the
internal 4–pole lowpass filter.
(b)
Vrms
Freescale Semiconductor, Inc...
(a)
• When an ac component is superimposed onto VCC near
the sampling frequency, as shown in Figure 4b, the output
will contain the original signal plus a mirrored signal about
the sampling frequency, shown in Figure 4a. Signals on the
VCC line will appear at the output due to the ratiometric
characteristic of the accelerometer and will be one half the
amplitude.
1000
• Good PCB layout practices should always be followed.
Proper system grounding is essential. Parasitic capacitance and inductance could prove to be troublesome, particularly during EMC testing. Signal harmonics and
sub–harmonics play a significant role in introducing aliased
signals. Clean layouts minimize the effects of parasitics
and thus signal harmonics and sub–harmonics.
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Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
AN1611
Impact Measurement Using Accelerometers
Prepared by: C.S. Chua
Sensor Application Engineering
Singapore, A/P
Freescale Semiconductor, Inc...
INTRODUCTION
This application note describes the concept of measuring
impact of an object using an accelerometer, microcontroller
hardware/software and a liquid crystal display. Due to the wide
frequency response of the accelerometer from d.c. to 400Hz,
the device is able to measure both the static acceleration from
the Earth’s gravity and the shock or vibration from an impact.
This design uses a 40G accelerometer (Motorola P/N:
MMA2200W) yields a minimum acceleration range of –40G to
+40G.
–q
+q
MMA2200W
SIDE VIEW
PCB
1.0 g
FRONT VIEW
Figure 1. Orientation of Accelerometer
REV 2
Motorola Sensor Device Data
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2–65
Freescale Semiconductor, Inc.
AN1611
CONCEPT OF IMPACT MEASUREMENT
During an impact, the accelerometer will be oriented as
shown in Figure 1 to measure the deceleration experienced by
the object from dc to 400Hz. Normally, the peak impact pulse
is in the order of a few miniseconds. Figure 2 shows a typical
crash waveform of a toy car having a stiff bumper.
50
PEAK IMPACT PULSE
40
30
DECELERATION (G)
Freescale Semiconductor, Inc...
20
10
0
–10
–20
–30
–40
0
10
20
30
40
50
60
TIME (ms)
Figure 2. Typical Crash Pattern
2–66
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Freescale Semiconductor, Inc.
HARDWARE DESCRIPTION AND OPERATION
Since MMA2200W is fully signal–conditioned by its internal
op–amp and temperature compensation, the output of the
accelerometer can be directly interfaced with an analog–to–
digital (A/D) converter for digitization. A filter consists of one
RC network should be added if the connection between the
output of the accelerometer and the A/D converter is a long
track or cable. This stray capacitance may change the position
of the internal pole which would drive the output amplifier of the
accelerometer into oscillation or unstability. In this design, the
cut–off frequency is chosen to be 15.9 kHz which also acts as
an anti–alias filter for the A/D converter. The 3dB frequency
can be approximated by the following equation.
Freescale Semiconductor, Inc...
f –3dB
1
+ 2πRC
Referring to the schematic, Figure 3, the MMA2200W
accelerometer is connected to PORT D bit 5 and the output of
the amplifier is connected to PORT D bit 6 of the microcontroller. This port is an input to the on–chip 8–bit analog–to–
digital (A/D) converter. Typically, the accelerometer provides
a signal output to the microprocessor of approximately 0.3 Vdc
at –55g to 4.7 Vdc at +55g of acceleration. However, Motorola
only guarantees the accuracy within ±40g range. Using the
same reference voltage for the A/D converter and accelerometer minimizes the number of additional components, but does
sacrifice resolution. The resolution is defined by the following:
count
255
The count at 0g = [2.5/5]
255 ∝ 128
The count at +25g = [3.5/5]
255 ∝ 179
The count at –25g = [1.5/5]
255 ∝ 77
Therefore the resolution 0.5g/count
The output of the accelerometer is ratiometric to the voltage
applied to it. The accelerometer and the reference voltages
are connected to a common supply; this yields a system that
is ratiometric. By nature of this ratiometric system, variations
in the voltage of the power supplied to the system will have no
effect on the system accuracy.
The liquid crystal display (LCD) is directly driven from I/O
ports A, B, and C on the microcontroller. The operation of a
Motorola Sensor Device Data
LCD requires that the data and backplane (BP) pins must be
driven by an alternating signal. This function is provided by a
software routine that toggles the data and backplane at
approximately a 30 Hz rate. Other than the LCD, one light
emitting diode (LED) are connected to the pulse length
converter (PLM) of the microcontroller. This LED will lights up
for 3 seconds when an impact greater or equal to 7g is
detected.
The microcontroller section of the system requires certain
support hardware to allow it to function. The MC34064P–5
provides an undervoltage sense function which is used to
reset the microprocessor at system power–up. The 4 MHz
crystal provides the external portion of the oscillator function
for clocking the microcontroller and provides a stable base for
time bases functions, for instance calculation of pulse rate.
SOFTWARE DESCRIPTION
Upon power–up the system, the LCD will display CAL for
approximately 4 seconds. During this period, the output of the
accelerometer are sampled and averaged to obtain the zero
offset voltage or zero acceleration. This value will be saved in
the RAM which is used by the equation below to calculate the
impact in term of g–force. One point to note is that the
accelerometer should remain stationary during the zero
calibration.
Impact
+ Vout
5
AN1611
+ [count * countoffset ]
resolution
In this software program, the output of the accelerometer is
calculated every 650µs. During an impact, the peak deceleration is measured and displayed on the LCD for 3 seconds
before resetting it to zero. In the mean time, if a higher impact
is detected, the value on the LCD will be updated accordingly.
However, when a low g is detected (e.g. 1.0g), the value will
not be displayed. Instead, more samples will be taken for
further averaging to eliminate the random noise and high
frequency component. Due to the fact that tilting is a low g and
low frequency signal, large number of sampling is preferred to
avoid unstable display. Moreover, the display value is not hold
for 3 seconds as in the case of an impact.
Figure 4 is a flowchart for the program that controls the
system.
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Freescale Semiconductor, Inc.
AN1611
MC34064
+5.0 V
G4
F4
A4
B4
C4
D4
E4
1
L
R1
LCD5657
Freescale Semiconductor, Inc...
+5.0 V
R5
R6
R7
JUMPER
OPEN
JUMPER
12
27
26
25
24
15
14
13
16
23
22
21
20
19
18
17
DP1
G1
F1
A1
4
B1
C1
D1 DP
E1
3
4.7 k
DP L
+5.0 V
8
DP3
DP2 2
32
G2
G3
31
F2 DP E
F F3 30
A2
A3
29
B2 D 1
G
A B3 11
C2
C3
10
C
B
D3
D2
9
E2
E3
3
/RESET
28
L
40
BP
1
BP
GND
37
36
35
34
7
6
5
INPUT
2
39
38
37
36
35
34
33
32
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
31
30
29
28
27
26
25
24
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
8
7
VRH
VRL
60
ROI
TCAP1
TCAP2
PD0/AN0
PD1/AN1
PD2/AN2
PD3/AN3
PD4/AN4
PD5/AN5
PD6/AN6
PD7/AN7
14
13
12
11
9
5
4
3
PC0
PC1
PC2/ECLK
PC3
PC4
PC5
PC6
PC7
49
48
47
46
45
44
43
42
PLMA
PLMB
20
21
TDO
SCLK
52
51
18
19
/RESET
/IRQ
OSC1
22
23
TCMP1
TCMP2
C3
MC68HC05B16CFN
2
1
4.0 MHz
10 M
VDD
22 p
17
R2
X1
OSC2
C4
10
16
+5.0 V
22 p
R4
J2
10 k
R3
C1
10 k
100 m
J1
+5.0 V
C2
100 n
+5.0 V
1
5.0 V REGULATOR
OUTPUT
GND
MC78L05ACP
C2′
R8
2
270 R
INPUT
10 n
D1
REWORK
3
5
MMA2200W
3
+5.0 V
4
OUTPUT
ON/OFF SWITCH
9.0 V BATTERY
1.0 k
SELF–TEST
VS
GND
BYPASS
C3′
2
6
C1′
0.1 m
Figure 3. Impact Measurement Schematic Drawing
2–68
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0.1 m
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
AN1611
START
INITIALIZATION CLEAR I/O PORTS
DISPLAY “CAL” FOR
4 SECONDS
AUTO–ZERO
Freescale Semiconductor, Inc...
READ ACCELEROMETER
CURRENT
VALUE > 2.0 g?
N
ACCUMULATE THE DATA
Y
IS THE NUMBER
OF SAMPLES ACCUMULATED
= 128?
IS THE IMPACT
> 7.0 g?
N
Y
Y
ACTIVATE THE
BUZZER / LED
IS THE CURRENT
VALUE > PEAK VALUE?
N
TAKE THE AVERAGE
OF THE DATA
Y
IS THE 3 SECOND
FOR THE PEAK VALUE
DISPLAY OVER?
N
N
Y
N
IS THE PEAK
VALUE BEEN DISPLAY >
3 SECOND?
OUTPUT THE CURRENT
VALUE TO LCD
Y
PEAK VALUE = CURRENT VALUE
SET 3 SECOND FOR THE TIMER INTERRUPT
OUTPUT PEAK VALUE
TO LCD
Motorola Sensor Device Data
Figure 4. Main Program Flowchart
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2–69
AN1611
Freescale Semiconductor, Inc.
Freescale Semiconductor, Inc...
SOFTWARE SOURCE/ASSEMBLY PROGRAM CODE
******************************************************************************
*
*
*
Accelerometer Demo Car Version 2.0
*
*
*
*
The following code is written for MC68HC705B16 using MMDS05 software
*
*
Version 1.01
*
*
CASM05 – Command line assembler Version 3.04
*
*
P & E Microcomputer Systems, Inc.
*
*
*
*
Written by : C.S. Chua
*
*
29 August 1996
*
*
*
*
*
*
Copyright Motorola Electronics Pte Ltd 1996
*
*
All rights Reserved
*
*
*
*
This software is the property of Motorola Electronics Pte Ltd.
*
*
*
*
Any usage or redistribution of this software without the express
*
*
written consent of Motorola is strictly prohibited.
*
*
*
*
Motorola reserves the right to make changes without notice to any
*
*
products herein to improve reliability, function, or design. Motorola
*
*
does not assume liability arising out of the application or use of any
*
*
product or circuit described herein, neither does it convey license
*
*
under its patents rights nor the rights of others. Motorola products are *
*
not designed, intended or authorised for use as component in systems
*
*
intended to support or sustain life or for any other application in
*
*
which the failure of the Motorola product could create a situation
*
*
a situation where personal injury or death may occur. Should the buyer
*
*
shall indemnify and hold Motorola products for any such unintended or
*
*
unauthorised application, buyer shall indemnify and hold Motorola and
*
*
its officers, employees, subsidiaries, affiliates, and distributors
*
*
harmless against all claims, costs, damages, expenses and reasonable
*
*
attorney fees arising out of, directly or indirectly, any claim of
*
*
personal injury or death associated with such unintended or unauthorised *
*
use, even if such claim alleges that Motorola was negligent regarding
*
*
the design or manufacture of the part.
*
*
*
*
Motorola and the Motorola logo are registered trademarks of Motorola Inc.*
*
*
*
Motorola Inc. is an equal opportunity/affirmative action employer.
*
*
*
******************************************************************************
******************************************************************************
*
*
*
Software Description
*
*
*
*
This software is used to read the output of the accelerometer MMA2200W
*
*
and display it to a LCD as gravity force. It ranges from –55g to +55g
*
*
with 0g as zero acceleration or constant velocity. The resolution is
*
*
0.5g.
*
*
*
*
The program will read from the accelerometer and hold the maximum
*
*
deceleration value for about 3.0 seconds before resetting. At the same
*
*
time, the buzzer/LED is activated if the impact is more than 7.0g.
*
*
However, if the maximum deceleration changes before 3.0 seconds, it
*
*
will update the display using the new value. Note that positive value
*
*
implies deceleration whereas negative value implies acceleration
*
*
*
******************************************************************************
******************************************
*
*
*
Initialisation
*
*
*
******************************************
PORTA
EQU
$00
; Last digit
PORTB
EQU
$01
; Second digit (and negative sign)
PORTC
EQU
$02
; First digit (and decimal point)
ADDATA
EQU
$08
; ADC Data
ADSTAT
EQU
$09
; ADC Status
PLMA
EQU
$0A
; Pulse Length Modulator (Output to Buzzer)
MISC
EQU
$0C
; Miscellaneous Register (slow/fast mode)
TCONTROL
EQU
$12
; Timer control register
TSTATUS
EQU
$13
; Timer Status Register
OCMPHI1
EQU
$16
; Output Compare Register 1 High Byte
2–70
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Freescale Semiconductor, Inc...
Freescale Semiconductor, Inc.
AN1611
OCMPLO1
EQU
$17
; Output Compare Register 1 Low Byte
TCNTHI
EQU
$18
; Timer Count Register High Byte
TCNTLO
EQU
$19
; Timer Count Register Low Byte
OCMPHI2
EQU
$1E
; Output Compare Register 2 High Byte
OCMPLO2
EQU
$1F
; Output Compare Register 2 Low Byte
******************************************
*
*
*
User–defined RAM
*
*
*
******************************************
SIGN
EQU
$54
; Acceleration (–) or deceleration (+)
PRESHI2
EQU
$55
; MSB of accumulated acceleration
PRESHI
EQU
$56
PRESLO
EQU
$57
; LSB of accumulated acceleration
PTEMPHI
EQU
$58
; Acceleration High Byte (Temp storage)
PTEMPLO
EQU
$59
; Acceleration Low Byte (Temp storage)
ACCHI
EQU
$5A
; Temp storage of acc value (High byte)
ACCLO
EQU
$5B
;
(Low byte)
ADCOUNTER
EQU
$5C
; Sampling Counter
AVERAGE_H
EQU
$5D
; MSB of the accumulated data of low g
AVERAGE_M
EQU
$5E
AVERAGE_L
EQU
$5F
; LSB of the accumulated data of low g
SHIFT_CNT
EQU
$60
; Counter for shifting the accumulated data
AVE_CNT1
EQU
$61
; Number of samples in the accumulated data
AVE_CNT2
EQU
$75
TEMPTCNTHI
EQU
$62
; Temp storage for Timer count register
TEMPTCNTLO
EQU
$63
; Temp storage for Timer count register
DECHI
EQU
$64
; Decimal digit high byte
DECLO
EQU
$65
; Decimal digit low byte
DCOFFSETHI
EQU
$66
; DC offset of the output (high byte)
DCOFFSETLO
EQU
$67
; DC offset of the output (low byte)
MAXACC
EQU
$68
; Maximum acceleration
TEMPHI
EQU
$69
TEMPLO
EQU
$6A
TEMP1
EQU
$6B
; Temporary location for ACC during delay
TEMP2
EQU
$6C
; Temporary location for ACC during ISR
DIV_LO
EQU
$6D
; No of sampling (low byte)
DIV_HI
EQU
$6E
; No of sampling (high byte)
NO_SHIFT
EQU
$6F
; No of right shift to get average value
ZERO_ACC
EQU
$70
; Zero acceleration in no of ADC steps
HOLD_CNT
EQU
$71
; Hold time counter
HOLD_DONE
EQU
$72
; Hold time up flag
START_TIME
EQU
$73
; Start of count down flag
RSHIFT
EQU
$74
; No of shifting required for division
ORG
$300
; ROM space 0300 to 3DFE (15,104 bytes)
DB
$FC
; Display ”0”
DB
$30
; Display ”1”
DB
$DA
; Display ”2”
DB
$7A
; Display ”3”
DB
$36
; Display ”4”
DB
$6E
; Display ”5”
DB
$EE
; Display ”6”
DB
$38
; Display ”7”
DB
$FE
; Display ”8”
DB
$7E
; Display ”9”
HUNDREDHI
DB
$00
; High byte of hundreds
HUNDREDLO
DB
$64
; Low byte of hundreds
TENHI
DB
$00
; High byte of tens
TENLO
DB
$0A
; Low byte of tens
******************************************
*
*
*
Program starts here upon hard reset *
*
*
******************************************
RESET
CLR
PORTC
; Port C = 0
CLR
PORTB
; Port B = 0
CLR
PORTA
; Port A = 0
LDA
#$FF
STA
$06
; Port C as output
STA
$05
; Port B as output
STA
$04
; Port A as output
LDA
TSTATUS
; Dummy read the timer status register
CLR
OCMPHI2
; so as to clear the OCF
CLR
OCMPHI1
LDA
OCMPLO2
JSR
COMPRGT
CLR
START_TIME
Motorola Sensor Device Data
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2–71
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AN1611
Freescale Semiconductor, Inc...
IDLE
REPEAT
SHIFTING
2–72
LDA
STA
CLI
LDA
STA
LDA
STA
LDA
STA
LDA
JSR
DECA
BNE
LDA
STA
LDA
STA
LDA
STA
JSR
LDX
LDA
STA
MUL
STA
TXA
STA
CLR
LDA
STA
LDA
STA
LDA
STA
LDA
STA
JSR
CLR
CLR
CLR
CLR
CLR
CLR
CLR
JSR
LDA
ADD
CMP
BLO
LDA
ADD
STA
CLRA
ADC
STA
CLRA
ADC
STA
LDA
ADD
STA
CLRA
ADC
STA
CMP
BNE
LDA
CMP
BNE
INC
LSR
ROR
ROR
LDA
CMP
BLO
LDA
#$40
TCONTROL
#$CC
PORTC
#$BE
PORTB
#$C4
PORTA
#16
DLY20
IDLE
#$00
DIV_LO
#$80
DIV_HI
#!15
NO_SHIFT
READAD
#5
PTEMPLO
ZERO_ACC
DCOFFSETLO
DCOFFSETHI
HOLD_CNT
#$10
DIV_LO
#$00
DIV_HI
#$4
NO_SHIFT
ZERO_ACC
MAXACC
ADTOLCD
START_TIME
AVE_CNT1
AVE_CNT2
SHIFT_CNT
AVERAGE_L
AVERAGE_M
AVERAGE_H
READAD
ZERO_ACC
#$04
PTEMPLO
CRASH
PTEMPLO
AVERAGE_L
AVERAGE_L
; Enable the output compare interrupt
; Interrupt begins here
; Port C = 1100 1100
Letter ”C”
; Port B = 1011 1110
Letter ”A”
; Port A = 1100 0100
Letter ”L”
;
;
;
;
;
;
;
;
Idling for a while (16*0.125 = 2 sec)
for the zero offset to stabilize
before perform auto–zero
Sample the data 32,768 times and take
the average 8000 H = 32,768
Right shift of 15 equivalent to divide
by 32,768
Overall sampling time = 1.033 s)
; Zero acceleration calibration
; Calculate the zero offset
; DC offset = PTEMPLO * 5
; Save the zero offset in the RAM
;
;
;
;
;
Sample the data 16 times and take
the average 0100 H = 16
Right shift of 4 equivalent to divide
by 16
Overall sampling time = 650 us
; Display 0.0g at the start
; Read acceleration from ADC
;
;
;
;
;
If the acceleration < 2.0g
Accumulate the averaged results
for 128 times and take the averaging
again to achieve more stable
reading at low g
AVERAGE_M
AVERAGE_M
AVERAGE_H
AVERAGE_H
#$01
AVE_CNT1
AVE_CNT1
AVE_CNT2
AVE_CNT2
#$04
REPEAT
AVE_CNT1
#$00
REPEAT
SHIFT_CNT
AVERAGE_H
AVERAGE_M
AVERAGE_L
SHIFT_CNT
#$0A
SHIFTING
AVERAGE_L
; Take the average of the 128 samples
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Freescale Semiconductor, Inc.
AN1611
STA
PTEMPLO
LDA
HOLD_CNT
; Check if the hold time of crash data
CMP
#$00
; is up
BNE
NON–CRASH
LDA
PTEMPLO
; If yes, display the current acceleration
STA
MAXACC
; value
JSR
ADTOLCD
BRA
NON–CRASH
CRASH
LDA
ZERO_ACC
ADD
#$0E
; If the crash is more than 7g
CMP
PTEMPLO
; 7g = 0E H * 0.5
BHS
NO_INFLATE
LDA
#$FF
; activate the LED
STA
PLMA
NO_INFLATE
JSR
MAXVALUE
; Display the peak acceleration
JSR
ADTOLCD
NON–CRASH
CLR
SHIFT_CNT
CLR
AVE_CNT1
CLR
AVE_CNT2
CLR
AVERAGE_L
CLR
AVERAGE_M
CLR
AVERAGE_H
BRA
REPEAT
; Repeat the whole process
******************************************
*
*
*
Delay Subroutine
*
*
(162 * 0.7725 ms = 0.125 sec)
*
*
*
******************************************
DLY20
STA
TEMP1
LDA
#!162
; 1 unit = 0.7725 ms
OUTLP
CLRX
INNRLP
DECX
BNE
INNRLP
DECA
BNE
OUTLP
LDA
TEMP1
RTS
******************************************
*
*
*
Reading the ADC data X times
*
*
and take the average
*
*
X is defined by DIV_HI and DIV_LO
*
*
*
******************************************
READAD
LDA
#$25
STA
ADSTAT
; AD status = 25H
CLR
PRESHI2
CLR
PRESHI
; Clear the memory
CLR
PRESLO
CLRX
CLR
ADCOUNTER
LOOP128
TXA
CMP
#$FF
BEQ
INC_COUNT
BRA
CONT
INC_COUNT
INC
ADCOUNTER
CONT
LDA
ADCOUNTER
; If ADCOUNTER = X
CMP
DIV_HI
; Clear bit = 0
BEQ
CHECK_X
; Branch to END100
BRA
ENDREAD
CHECK_X
TXA
CMP
DIV_LO
BEQ
END128
ENDREAD
BRCLR
7,ADSTAT,ENDREAD ; Halt here till AD read is finished
LDA
ADDATA
; Read the AD register
ADD
PRESLO
; PRES = PRES + ADDATA
STA
PRESLO
CLRA
ADC
PRESHI
STA
PRESHI
CLRA
ADC
PRESHI2
STA
PRESHI2
INCX
; Increase the AD counter by 1
BRA
LOOP128
; Branch to Loop128
END128
CLR
RSHIFT
; Reset the right shift counter
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DIVIDE
INC
RSHIFT
; Increase the right counter
LSR
PRESHI2
ROR
PRESHI
; Right shift the high byte
ROR
PRESLO
; Right shift the low byte
LDA
RSHIFT
CMP
NO_SHIFT
; If the right shift counter >= NO_SHIFT
BHS
ENDDIVIDE
; End the shifting
JMP
DIVIDE
; otherwise continue the shifting
ENDDIVIDE
LDA
PRESLO
STA
PTEMPLO
RTS
******************************************
*
*
*
Timer service interrupt
*
*
Alternates the Port data and
*
*
backplane of LCD
*
*
*
******************************************
TIMERCMP
STA
TEMP2
; Push Accumulator
COM
PORTC
; Port C = – (Port C)
COM
PORTB
; Port B = – (Port B)
COM
PORTA
; Port A = – (Port A)
LDA
START_TIME
; Start to count down the hold time
CMP
#$FF
; if START_TIME = FF
BNE
SKIP_TIME
JSR
CHECK_HOLD
SKIP_TIME
BSR
COMPRGT
; Branch to subroutine compare register
LDA
TEMP2
; Pop Accumulator
RTI
******************************************
*
*
*
Check whether the hold time
*
*
of crash impact is due
*
*
*
******************************************
CHECK_HOLD
DEC
HOLD_CNT
LDA
HOLD_CNT
CMP
#$00
; Is the hold time up?
BNE
NOT_YET
LDA
#$00
; If yes,
STA
PLMA
; stop buzzer
LDA
#$FF
; Set HOLD_DONE to FF indicate that the
STA
HOLD_DONE
; hold time is up
CLR
START_TIME
; Stop the counting down of hold time
NOT_YET
RTS
******************************************
*
*
*
Subroutine reset
*
*
the timer compare register
*
*
*
******************************************
COMPRGT
LDA
TCNTHI
; Read Timer count register
STA
TEMPTCNTHI
; and store it in the RAM
LDA
TCNTLO
STA
TEMPTCNTLO
ADD
#$4C
; Add 1D4C H = 7500 periods
STA
TEMPTCNTLO
; with the current timer count
LDA
TEMPTCNTHI
; 1 period = 2 us
ADC
#$1D
STA
TEMPTCNTHI
; Save the next count to the register
STA
OCMPHI1
LDA
TSTATUS
; Clear the output compare flag
LDA
TEMPTCNTLO
; by access the timer status register
STA
OCMPLO1
; and then access the output compare
RTS
; register
******************************************
*
*
*
Determine which is the next
*
*
acceleration value to be display
*
*
*
******************************************
MAXVALUE
LDA
PTEMPLO
CMP
MAXACC
; Compare the current acceleration with
BLS
OLDMAX
; the memory, branch if it is <= maxacc
BRA
NEWMAX1
OLDMAX
LDA
HOLD_DONE
; Decrease the Holdtime when
CMP
#$FF
; the maximum value remain unchanged
2–74
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AN1611
BEQ
NEWMAX1
; Branch if the Holdtime is due
LDA
MAXACC
; otherwise use the current value
BRA
NEWMAX2
NEWMAX1
LDA
#$C8
; Hold time = 200 * 15 ms = 3 sec
STA
HOLD_CNT
; Reload the hold time for the next
CLR
HOLD_DONE
; maximum value
LDA
#$FF
STA
START_TIME
; Start to count down the hold time
LDA
PTEMPLO
; Take the current value as maximum
NEWMAX2
STA
MAXACC
RTS
******************************************
*
*
*
This subroutine is to convert
*
*
the AD data to the LCD
*
*
Save the data to be diaplayed
*
*
in MAXACC
*
*
*
******************************************
ADTOLCD
SEI
; Disable the Timer Interrupt !!
LDA
#$00
; Load 0000 into the memory
STA
DECHI
LDA
#$00
STA
DECLO
LDA
MAXACC
LDX
#5
MUL
; Acceleration = AD x 5
ADD
DECLO
; Acceleration is stored as DECHI
STA
DECLO
; and DECLO
STA
ACCLO
; Temporary storage
LDA
#$00
; Assume positive deceleration
STA
SIGN
; ”00” positive ; ”01” negative
CLRA
TXA
ADC
DECHI
STA
DECHI
STA
ACCHI
; Temporary storage
LDA
DECLO
SUB
DCOFFSETLO
; Deceleration = Dec – DC offset
STA
DECLO
LDA
DECHI
SBC
DCOFFSETHI
STA
DECHI
BCS
NEGATIVE
; Branch if the result is negative
BRA
SEARCH
NEGATIVE
LDA
DCOFFSETLO
; Acceleration = DC offset – Dec
SUB
ACCLO
STA
DECLO
LDA
DCOFFSETHI
SBC
ACCHI
STA
DECHI
LDA
#$01
; Assign a negative sign
STA
SIGN
SEARCH
CLRX
; Start the search for hundred digit
LOOP100
LDA
DECLO
; Acceleration = Acceleration – 100
SUB
HUNDREDLO
STA
DECLO
LDA
DECHI
SBC
HUNDREDHI
STA
DECHI
INCX
; X = X + 1
BCC
LOOP100
; if acceleration >= 100, continue the
DECX
; loop100, otherwise X = X – 1
LDA
DECLO
; Acceleration = Acceleration + 100
ADD
HUNDREDLO
STA
DECLO
LDA
DECHI
ADC
HUNDREDHI
STA
DECHI
TXA
; Check if the MSD is zero
AND
#$FF
BEQ
NOZERO
; If MSD is zero, branch to NOZERO
LDA
$0300,X
; Output the first second digit
STA
PORTC
BRA
STARTTEN
NOZERO
LDA
#$00
; Display blank if MSD is zero
STA
PORTC
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STARTTEN
LOOP10
CLRX
; Start to search for ten digit
LDA
DECLO
; acceleration = acceleration – 10
SUB
TENLO
STA
DECLO
LDA
DECHI
SBC
TENHI
STA
DECHI
INCX
BCC
LOOP10
; if acceleration >= 10 continue the
DECX
; loop, otherwise end
LDA
DECLO
; acceleration = acceleration + 10
ADD
TENLO
STA
DECLO
LDA
DECHI
ADC
TENHI
STA
DECHI
LDA
$0300,X
; Output the last second digit
EOR
SIGN
; Display the sign
STA
PORTB
CLRX
; Start to search for the last digit
LDA
DECLO
; declo = declo – 1
TAX
LDA
$0300,X
; Output the last digit
EOR
#$01
; Add a decimal point in the display
STA
PORTA
CLI
; Enable Interrupt again !
RTS
******************************************
*
*
*
This subroutine provides services
*
*
for those unintended interrupts
*
*
*
******************************************
SWI
RTI
; Software interrupt return
IRQ
RTI
; Hardware interrupt
TIMERCAP
RTI
; Timer input capture
TIMERROV
RTI
; Timer overflow
SCI
RTI
; Serial communication Interface
; Interrupt
ORG
$3FF2
; For 68HC05B16, the vector location
FDB
SCI
; starts at 3FF2
FDB
TIMERROV
; For 68HC05B5, the address starts
FDB
TIMERCMP
; 1FF2
FDB
TIMERCAP
FDB
IRQ
FDB
SWI
FDB
RESET
2–76
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MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
AN1612
Shock and Mute Pager Applications
Using Accelerometer
INTRODUCTION
30
In the current design, whenever there is an incoming page,
the buzzer will “beep” until any of the buttons is depressed. It
can be quite annoying or embarrassing sometime when the
button is not within your reach. This application note describes
the concept of muting the “beeping” sound by tapping the
pager lightly, which could be located in your pocket or handbag. This demo board uses an accelerometer, microcontroller
hardware/software and a piezo audio transducer. Due to the
wide frequency response of the accelerometer from d.c. to
400Hz, the device is able to measure both the static acceleration from the Earth’s gravity and the shock or vibration from an
impact. This design uses a 40G accelerometer (Motorola P/N:
MMA1201P) which yields a minimum acceleration range of
–40G to +40G.
20
ACCELEROMETER OUTPUT (G)
Freescale Semiconductor, Inc...
Prepared by: C.S. Chua
Sensor Application Engineering
Singapore, A/P
10
0
– 10
– 20
– 30
TAPPING OF
ACCELEROMETER
– 40
– 50
– 60
– 70
– 0.05
– 0.03
– 0.01
0
0.01
0.03
0.05
TIME (seconds)
CONCEPT OF TAP DETECTION
To measure the tapping of a pager, the accelerometer must
be able to respond in the range of hundreds of hertz. During the
tapping of a pager at the top surface, which is illustrated in
Figure 1, the accelerometer will detect a negative shock level
between –15g to –50g of force depending on the intensity.
Similarly, if the tapping action comes from the bottom of the
accelerometer, the output will be a positive value. Normally, the
peak impact pulse is in the order of a few milliseconds. Figure 2
shows a typical waveform of the accelerometer under shock.
TAPPING ACTION
FRONT VIEW
PCB
Figure 1. Tapping Action of Accelerometer
Figure 2. Typical Waveform of Accelerometer Under
Tapping Action
Therefore, we could set a threshold level, either by hardware circuitry or software algorithm, to determine the tapping
action and mute the “beeping”. In this design, a hardware
solution is used because there will be minimal code added to
the existing pager software. However, if a software solution is
used, the user will be able to program the desire shock level.
HARDWARE DESCRIPTION AND OPERATION
Since MMA1201P is fully signal–conditioned by its internal
op–amp and temperature compensation, the output of the accelerometer can be directly interfaced with a comparator. To
simplify the hardware, only one direction (tapping on top of the
sensor) is monitored. The comparator is configured in such a
way that when the output voltage of the accelerometer is less
than the threshold voltage or Vref (refer to Figure 3), the output
of the comparator will give a logic “1” which is illustrated in
Figure 4. To decrease the Vref voltage or increase the threshold
impact in magnitude, turn the trimmer R2 anti–clockwise.
REV 3
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AN1612
For instance, if the threshold level is to be set to –20g, this
will correspond to a Vref voltage of 1.7 V.
+5.0 V
VREF
8
3
VIN
2
VREF
R1
VOUT
7
6
1 5
100 k
2
+
100 k
R2
C3
1.0 m
OFFSET
THRESHOLD
Ǔ
Under normal condition, Vin (which is the output of the
accelerometer) is at about 2.5V. Since Vin is higher than Vref,
the output of the comparator is at logic “0”. During any shock
or impact which is greater than –20g in magnitude, the output
voltage of the accelerometer will go below Vref. In this case,
the output logic of the comparator changes from “0” to “1”.
When the pager is in silence mode, the vibrator produces an
output of about ±2g. This will not trigger the comparator.
Therefore, even in silence mode, the user can also tap the
pager to stop the alert. Refer to Figure 5 for the vibrator
waveform.
1
Figure 3. Comparator Circuitry
6.0
2.0
1.5
VIBRATOR MOVEMENT (G)
5.0
4.0
V OUT (V)
Freescale Semiconductor, Inc...
U1
+
4
+5.0 V
LM311N
–
ǒ
+ V ) DDGV G
+ 2.5 ) (0.04 [* 20])
+ 1.7 V
3.0
2.0
1.0
0.5
0
– 0.5
–1.0
1.0
–1.5
0
– 0.05
– 0.03
– 0.01
0
0.01
0.03
0.05
– 2.0
– 0.025
– 0.015
– 0.005
TIME (seconds)
0.005
0.015
0.025
TIME (seconds)
Figure 4. Comparator Output Waveform
2–78
0
Figure 5. Vibrator Waveform
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Figure 6 is a schematic drawing of the whole demo and
Figures 7, 8, and 9 show the printed circuit board and compo-
AN1612
nent layout for the shock and mute pager. Table 1 is the corresponding part list.
R4
MC78L05ACP
3
J2
INPUT
1
2
C10
OUTPUT
GND
2
0.33 m
+5.0 V
1
10 M
+5.0 V
C9
X1
C3
0.1 m
16
10 k
18
19
+5.0 V
S1
C5
41
0.1 m
U1
8
C7
VS
OUTPUT
6
C1
0.1 m
8
R8
5
3
1.0 k
BYPASS
SELF–TEST
MMA1201P
2
C8
4
0.1 m
10 n
R3
10 k
LM311N
–
U2
+
4
6
1 5
7
+5.0 V
GND
7
R7
+5.0 V
R1
10 k
J1
100 k
R6
2
R2
1
180 R
100 k
+
C12
OSC1
/RESET
/IRQ
22
TCAP1
23
TCAP2
10 n
+5.0 V
C2
C4
22 p
U5
R5
Freescale Semiconductor, Inc...
4 MHz
22 p
1.0 m
D1
VSS
8
VRH
7
VRL
31
PA0
30
PA1
29
PA2
28
PA3
27
PA4
26
PA5
25
PA6
24
PA7
39
38
37
36
35
34
33
32
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
+5.0 V
R9
10 k
OSC2
VDD
17
+5.0 V
10
2
TCMP1
1
TCMP2
C6
10 n
C11 +
47 m
52
TDO
51
SCLK
20
PLMA
21
PLMB
PC0
PC1
PC2/ECLK
PC3
PC4
PC5
PC6
PC7
PD0/AN0
PD1/AN1
PD2/AN2
PD3/AN3
PD4/AN4
PD5/AN5
PD6/AN6
PD7/AN7
49
48
47
46
45
44
43
42
U4
PIEZO
TRANSDUCER
14
13
12
11
9
5
4
3
MC68HC705B16CFN
U3
S2
Figure 6. Overall Schematic Diagram of the Demo
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AN1612
SHOCK & MUTE
PAGER
9V
D1
U4
GND
J2
C9
U5
R6
R3
R1
C10
U2
U1
C7 C8 C2 C1
C12
C6
R2
R4
C3
X1
S1
C11
R8
S2
C4
R5
R7
J1
U3
Freescale Semiconductor, Inc...
R9
C5
Figure 7. Silk Screen of the PCB
Figure 8. Solder Side of the PCB
Table 1. Bill of Material for the Shock and Mute Pager
Device Type
Qty.
Value
References
Ceramic Capacitor
4
0.1µ
C1, C2, C7, C9
Ceramic Capacitor
2
22p
C3, C4
Ceramic Capacitor
3
10n
C5, C6, C8
Solid Tantalum
1
0.33µ
C10
Electrolytic Capacitor
1
47µ
C11
Electrolytic Capacitor
1
1µ
C12
LED
1
5mm
D1
Header
1
2 way
J1
PCB Terminal Block
1
2 way
J2
Resistor
1
100k
R1
Single Turn Trimmer
1
100k
R2
Resistor
4
10k
R3, R5, R7, R9
1
10M
R4
1
180R
R6
1
1k
R8
Push Button
2
6mm
S1, S2
MMA1201P
1
—
U1
LM311N
1
—
U2
MC68HC705B16CFN
1
—
U3
Piezo Transducer
1
—
U4
MC78L05ACP
1
—
U5
Crystal
1
4MHz
X1
"5% 0.25W
"5% 0.25W
Resistor "5% 0.25W
Resistor "5% 0.25W
Resistor "5% 0.25W
2–80
Figure 9. Component Side of the PCB
SOFTWARE DESCRIPTION
Upon powering up the system, the piezo audio transducer
is activated simulating an incoming page, if the pager is in
sound mode (jumper J1 in ON). Then, the accelerometer is
powered up and the output of the comparator is sampled to
obtain the logic level. The “beeping” will continue until the
accelerometer senses an impact greater than the threshold
level. Only then the alert is muted. However when the pager
is in silence mode (jumper J1 is OFF), which is indicated by the
blinking red LED, the accelerometer is not activated. To stop
the alert, press the push–button S2.
To repeat the whole process, simply push the reset switch S1.
Figure 10 is a flowchart for the program that controls the
system.
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AN1612
RECEIVE A PAGE
Y
IS IT IN
SILENCE MODE?
N
TURN ON THE
SHOCK SENSOR
Freescale Semiconductor, Inc...
N
IS BUTTON
ACTIVATED?
Y
IS SHOCK
SENSOR ACTIVATED
OR BUTTON
ACTIVATED?
N
Y
TURN OFF THE
SHOCK SENSOR
TURN OFF THE
BUZZER OR VIBRATOR
END
Figure 10. Main Program Flowchart
CONCLUSION
The shock and mute pager design uses a comparator to
create a logic level output by comparing the accelerometer
output voltage and a user–defined reference voltage. The
Motorola Sensor Device Data
flexibility of this minimal component, high performance design
makes it compatible with many different applications, e.g. hard
disk drive knock sensing, etc. The design presented here uses
a comparator which yields excellent logic–level outputs and
output transition speeds for many applications.
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AN1612
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Freescale Semiconductor, Inc...
SOFTWARE SOURCE/ASSEMBLY PROGRAM CODE
******************************************************************************
*
*
*
Pager Shock & Mute Detection Version 1.0
*
*
*
*
The following code is written for MC68HC705B16 using MMDS05 software
*
*
Version 1.01
*
*
CASM05 – Command line assembler Version 3.04
*
*
P & E Microcomputer Systems, Inc.
*
*
*
*
Written by : C.S. Chua
*
*
9th January 1997
*
*
*
*
Software Description
*
*
*
*
J1 ON – Sound mode
*
*
Buzzer will turn off if the accelerometer is tapped or switch S2 is
*
*
depressed.
*
*
*
*
J1 OFF – Silence mode
*
*
LED will turn off if and only if S2 is depressed
*
*
*
******************************************************************************
******************************************
*
*
*
I/O Declaration
*
*
*
******************************************
PORTB
EQU
$01
; Port B
PLMA
EQU
$0A
; D/A to control buzzer
TCONTROL
EQU
$12
; Timer control register
TSTATUS
EQU
$13
; Timer Status Register
OCMPHI1
EQU
$16
; Output Compare Register 1 High Byte
OCMPLO1
EQU
$17
; Output Compare Register 1 Low Byte
TCNTHI
EQU
$18
; Timer Count Register High Byte
TCNTLO
EQU
$19
; Timer Count Register Low Byte
OCMPHI2
EQU
$1E
; Output Compare Register 2 High Byte
OCMPLO2
EQU
$1F
; Output Compare Register 2 Low Byte
******************************************
*
*
*
RAM Area ($0050 – $0100)
*
*
*
******************************************
ORG
$50
STACK
RMB
4
; Stack segment
TEMPTCNTLO
RMB
1
; Temp. storage of timer result (LSB)
TEMPTCNTHI
RMB
1
; Temp. storage of timer result (MSB)
******************************************
*
*
*
ROM Area ($0300 – $3DFD)
*
*
*
******************************************
ORG
$300
******************************************
*
*
*
Program starts here upon hard reset *
*
*
******************************************
RESET
CLR
PORTB
; Initialise Ports
LDA
#%01001000
; Configure Port B
STA
$05
LDA
TSTATUS
; Dummy read the timer status register so as to clear the OCF
CLR
OCMPHI2
CLR
OCMPHI1
LDA
OCMPLO2
JSR
COMPRGT
LDA
#$40
; Enable the output compare interrupt
STA
TCONTROL
LDA
#10
; Idle for a while before ”beeping”
IDLE
JSR
DLY20
DECA
BNE
IDLE
CLI
; Interrupt begins here
BRSET
1,PORTB,SILENCE
; Branch if J1 is off
BSET
6,PORTB
; Turn on accelerometer
JSR
DLY20
; Wait till the supply is stable
TEST
BRSET
5,PORTB,MUTE
; Sample shock sensor for tapping
BRCLR
7,PORTB,MUTE
; Sample switch S2 for muting
JMP
TEST
MUTE
BCLR
6,PORTB
; Turn off accelerometer
SEI
CLR
PLMA
; Turn off buzzer
2–82
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DONE
SILENCE
JMP
DONE
; End
BRSET
7,PORTB,SILENCE
; Sample switch S2 for stopping LED
SEI
BCLR
3,PORTB
; Turn off LED
JMP
DONE
; End
******************************************
*
*
*
Timer service interrupt
*
*
Alternates the PLMA data
*
*
and bit 3 of Port B
*
*
*
******************************************
TIMERCMP
BSR
COMPRGT
; Branch to subroutine compare register
BRSET
1,PORTB,SKIPBUZZER ; Branch if J1 is OFF
LDA
PLMA
EOR
#$80
; Alternate the buzzer
STA
PLMA
RTI
SKIPBUZZER
BRSET
3,PORTB,OFF_LED
; Alternate LED supply
BSET
3,PORTB
RTI
OFF_LED
BCLR
3,PORTB
RTI
******************************************
*
*
*
Subroutine reset
*
*
the timer compare register
*
*
*
******************************************
COMPRGT
LDA
TCNTHI
; Read Timer count register
STA
TEMPTCNTHI
; and store it in the RAM
LDA
TCNTLO
STA
TEMPTCNTLO
ADD
#$50
; Add C350 H = 50,000 periods
STA
TEMPTCNTLO
; with the current timer count
LDA
TEMPTCNTHI
; 1 period = 2 us
ADC
#$C3
STA
TEMPTCNTHI
; Save the next count to the register
STA
OCMPHI1
LDA
TSTATUS
; Clear the output compare flag
LDA
TEMPTCNTLO
; by access the timer status register
STA
OCMPLO1
; and then access the output compare register
RTS
******************************************
*
*
*
Delay Subroutine for 0.20 sec
*
*
*
*
Input: None
*
*
Output: None
*
*
*
******************************************
DLY20
STA
STACK+2
STX
STACK+3
LDA
#!40
; 1 unit = 0.7725 mS
OUTLP
CLRX
INNRLP
DECX
BNE
INNRLP
DECA
BNE
OUTLP
LDX
STACK+3
LDA
STACK+2
RTS
******************************************
*
*
*
This subroutine provides services
*
*
for those unintended interrupts
*
*
*
******************************************
SWI
RTI
; Software interrupt return
IRQ
RTI
; Hardware interrupt
TIMERCAP
RTI
; Timer input capture
TIMERROV
RTI
; Timer overflow interrupt
SCI
RTI
; Serial communication Interface Interrupt
ORG
$3FF2
; For 68HC05B16, the vector location
FDB
SCI
; starts at 3FF2
FDB
TIMERROV
; For 68HC05B5, the address starts at 1FF2
FDB
TIMERCMP
FDB
TIMERCAP
FDB
IRQ
FDB
SWI
FDB
RESET
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MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
AN1632
MMA1201P Product Overview
and Interface Considerations
Freescale Semiconductor, Inc...
Prepared by: Carlos Miranda
Systems and Applications Engineer
and
Gary O’Brien
New Product Development Engineer
INTRODUCTION
Silicon micromachined accelerometers designed for a variety of applications including automotive airbag deployment
systems must meet stringent performance requirements and
still remain low cost. Achieving the requisite enhanced functionality encompasses overcoming challenges in both transducer micromachining and subsequent signal conditioning.
Motorola’s accelerometer architecture includes two separate
elements in a single package to achieve overall functionality:
a sensing element (“g–cell”) and a signal conditioning element
(“control ASIC”).
Figure 1 shows a functional block diagram of Motorola’s
new MMA1201P. The transducer is a surface micromachined
differential capacitor with two fixed plates and a third movable plate. The movable plate is attached to an inertial mass.
When acceleration is applied to the device, the inertial mass
is displaced causing a change in capacitance. The second
die is a CMOS control ASIC which acts as a capacitance to
voltage converter and conditions the signal to provide a high
level output. The output signal has an offset voltage nominally equivalent to VDD/2 so that both positive and negative
acceleration can be measured.
G–Cell
This document describes Motorola’s new MMA1201P
accelerometer, which uses a new control ASIC architecture.
It explains important new features that have been incorporated into the ASIC, and presents an overview of the key
performance characteristics of the new accelerometer. The
document also details the minimum supporting circuitry
needed to operate a Motorola accelerometer and interface it
to an MCU. Finally, the power supply rejection ratio (PSRR)
characteristics and an aliasing gain model are presented.
MMA1201P FEATURES
Several design enhancements have been implemented into
the new MMA1201P. The oscillator circuit, which is the heart
of the ASIC, has been redesigned to improve stability over
temperature. A filter has been added to the power supply line
for internally generated biases. A new sensing scheme is used
to sample the differential capacitor transducer and condition
the signal. Finally, the temperature compensation stage has
been redesigned to be trimmable. A block diagram representation of the new accelerometer, in a 16 pin DIP package, is
shown in Figure 1. For simplicity, the EPROM trim and the
self–test circuit blocks have been omitted.
CMOS Control ASIC
Capacitance
to Voltage
Converter
VDD
Filter
ST
Trimmable
Gain
Stage
Trimmable
Switched
Capacitor
Filter
Trimmable
Temp. Comp.
Output Stage
Oscillator
VOUT
VSS
VDD
Figure 1. Block Diagram Representing the MMA1201P
REV 2
2–84
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• Oscillator
The oscillator has been redesigned to center the nominal
frequency within the trimming range and to have better
temperature compensation. As shown in Figure 1, the
oscillator controls three switched capacitor circuit sub–
blocks within the ASIC, thus having direct impact on their
performance. The trimmable oscillator enhances the control of other performance parameters and enables the part
to meet tighter specification tolerances. Additionally, the
placement of the oscillator on the silicon die has changed,
contributing to a 50% reduction in the noise of the part.
• Power Supply Filter
An internal capacitor has been added between the VDD and
VSS pins to provide some de–coupling of the power supply.
Also, a lowpass filter has been added to the circuitry that
supplies power to the transducer element and that sets the
DC level of the capacitance–to–voltage converter stage.
The filter response suppresses high frequency noise, but
maintains a ratiometric output.
• New Sensing Scheme
The capacitance–to–voltage converter employs innovative
circuit techniques (at the time of this writing, patents are
pending) to improve signal ratiometricity. Amplification is
achieved using an EPROM trimmable gain stage, providing capability for both coarse and fine tuning. As in the
previous version of the control ASIC, the second gain stage
is cascaded by a switched capacitor four pole Bessel lowpass filter, with a unity gain response and –3 dB frequency
at 400 Hz.
• Temperature Compensation
The final stage in the ASIC performs temperature compensation of gain. Thus, the temperature coefficient for
sensitivity is set using EPROM trim.
PERFORMANCE ENHANCEMENTS
Motorola’s new MMA1201P accelerometer provides performance enhancements in a number of areas, including ratiometric output, signal–to–noise ratio, output filter response,
and temperature compensation. For complete details, refer to
the MMA1201P data sheet.
• Ratiometric Output
The offset voltage and the sensitivity of the part are ratiometric with supply voltage. Typical error values are less
than 0.5%.
• Signal to Noise Ratio
The noise has been reduced by 50% and is specified at
3.5 mV RMS maximum. Typical values are about
2.0 mV RMS . As a result, the signal to noise ratio of the
part is about 50 dB.
• Lowpass Filter Response
The frequency response of the four pole Bessel lowpass
filter has the –3 dB frequency at 400 Hz. The tolerance has
been narrowed by 60% and is specified at 40 Hz.
"
• Temperature Compensation
The sensitivity is very uniform over temperature, with typical errors of about 1% over the specified temperature
range. Also, although the spec allows for the equivalent of
"
Motorola Sensor Device Data
AN1632
5 mV/°C for the temperature coefficient of offset, typical
values are actually less than 2 mV/°C, at VDD equal to 5 V.
INTERFACE CONSIDERATIONS
With only four active pin connections, Motorola’s accelerometers are very easy to use. There are only a few simple
considerations to be taken into account to ensure reliable
operation and attain the high level of performance that the can
part offer.
• Power Supply
Power is applied to the accelerometer through the VDD pin.
For optimum performance, it is recommended that the part
be powered with a voltage regulator such as the Motorola
MC78L05. An optional 0.1 µF capacitor can be placed on
the VDD pin to complement the accelerometer’s internal
capacitor and provide additional de–coupling of the supply.
The capacitor should be physically located as close as
possible to the accelerometer.
• Ground
Ground is applied through the VSS pin. Whenever possible it is recommended that a solid ground plane be used
so that the impedance of the ground path is minimized. If
this is not possible, it is strongly recommended that a low
impedance trace (no additional components should be
connected to it) be used to directly connect the VSS pin to
the power supply ground.
• Self–test
The ST pin is an active, high logic level input pin that provides a way for the user to verify proper operation of the
part. It is pulled down internally. Therefore, for normal
operation, the user could apply a logic level “0” or leave it
unconnected. Applying a logic level “1” to the ST pin will
apply the equivalent of a 25 g acceleration to the transducer, and the user should see a change in the output
equivalent to 25 times the part’s rated sensitivity.
• Output
The accelerometer’s output is measured at the VOUT pin.
As shown in Figure 1, the ASIC’s oscillator controls the
switched capacitor lowpass filter, with a nominal operating
frequency of 65 kHz. As a result, a clock noise component
of about 2 mVpeak may be present at 65 kHz. Therefore, it
is recommended that the user place a simple RC lowpass
filter on the VOUT pin to reduce the clock noise present in
the output signal. Recommended values are a 1 kΩ resistor
and a 0.01 µF capacitor. These values produce a filter with
a –3 dB frequency at about 16 kHz, which will not interfere
with the response of the internal Bessel filter, yet will provide sufficient attenuation (approximately –12 dB) of the
clock noise.
Placing a filter on the output is especially recommended for
applications where the signal will be fed into a stand–alone
A/D converter, and in cases where the signal will be amplified to a level where the amplified clock noise may begin to
contribute significantly to the noise floor of the system.
However, if using an MCU or microprocessor in the system,
the user may choose to use a software algorithm to digitally
filter the signal, instead of using the analog RC filter. This
option would have to be evaluated based on the system
performance requirements.
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AN1632
• Connection to the A/D on an MCU
When using the accelerometer with the analog to digital
converter on an MCU, it is important to connect the supply
and ground pins of the accelerometer and the VRH and VRL
pins of the MCU to the same supply and ground traces,
respectively. This will maximize the ratiometricity of the
system by avoiding voltage differences that may result
from trace impedances.
Figure 2 shows the recommended supporting circuitry for
operating the new accelerometer. Part (a) shows the16 pin
DIP package version, the MMA1201P, while part (b) shows the
6 pin Wingback package version, the MMA2200W. For the
MMA1201P, pins 1, 2, 3, 6, 14, 15, and 16 have no internal
connections, and pins 9 through 13 are used for calibration
and trimming in the factory. These pins should all be left unconnected. For the MMA2200W, pins 1 and 4, and the wings
(supporting pins) should be left unconnected.
MMA1201P
VCC
LOGIC INPUT
4 ST
R1
8 VDD
C1
5
11 TRIM 3
0.1 m F
Freescale Semiconductor, Inc...
VOUT
1k
W
OUTPUT SIGNAL
C2
m
0.01 F
7 VSS
(a)
MMA2200W
VCC
LOGIC INPUT
2 ST
R1
6 VDD
C1
m
0.1 F
VOUT
3
1k
W
OUTPUT SIGNAL
C2
m
0.01 F
5 VSS
(b)
Figure 2. Accelerometers with Recommended Supporting Circuitry
PSRR AND ALIASING GAIN MODEL
Although the operational amplifiers in the MMA1201P’s
control ASIC have a high power supply rejection ratio with a
fairly wide bandwidth, because the accelerometer is in reality
a sampled analog system using switched capacitor technology, it is possible that when powered with a switching power
supply, noise from the supply will appear in the output signal.
This is known as aliasing, the result being a signal with frequency equal to the difference between the frequency of the
power supply noise and the accelerometer’s sampling frequency. Aliasing gain is defined as the power of the output
signal relative to an injected sinusoid on the VDD line powering
the accelerometer.
Typical switching power supplies have operating frequencies between 50 and 100 kHz. The operating frequency of the
accelerometer’s switching capacitor circuitry is roughly 65
kHz. Should the fundamental frequency of the switching
power supply, or its harmonics, fall within 400 Hz of the ASIC’s
fundamental frequency (or its harmonics), then any noise
present in the power supply will be aliased into the passband
of the accelerometer. As will be explained later in this section,
there are several simple ways to avoid aliasing.
2–86
As shown in Figure 1, there are many different signal processing stages in the ASIC. As a result, the aliasing gain
characteristics of the part are a little bit more complex than
explained in the previous paragraph. An analysis was done to
characterize the worst case aliasing gain of the accelerometer. Devices from three production lots were used. The parts
were tested at 105_C with 5.25 V on VDD. The gain code was
set to the nominal value plus 4σ. Thus, the parts had a sensitivity that was approximately twice that of standard parts.
Figure 3, shows a plot of the aliasing gain model that was
developed. The model is based on the worst case results;
typical parts should perform much better having much lower
aliasing gain.
The following equation was used to fit the data and generate
the model:
Aliasing Gain = 1.6965 + 0.0029 * Freq. (kHz) + HRC1
* Freq. (kHz) + HRC2
where HRC1 and HRC2 are coefficients used in the model.
Their values vary for each harmonic. Figure 4 lists the values
of HRC1 and HRC2 for the fundamental frequency and the first
5 harmonics.
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AN1632
3.5
3
ALIASING GAIN (V/V)
2.5
2
1.5
Freescale Semiconductor, Inc...
1
0.5
0
0
Fundamental
1st
2nd
3rd
4th
5th
SAMPLING FREQUENCY AND HARMONICS
Figure 3. Worst Case Aliasing Gain Model Derived from Characterization Data
Harmonic
Freq. (kHz)
Fundamental
65
HRC1
HRC2
*2.1120
*1.4881
*4.1572
*0.2919
0.0101
1st
130
*0.0016
2nd
195
0.0237
3rd
260
4th
325
5th
390
*0.0060
*0.0098
*0.0164
Aliasing Gain
0.4242
0.3674
2.7116
0.6007
3.7439
3.2017
4.3054
0.7361
Figure 4. Values for Worst Case Aliasing Gain Model
The aliasing gain model can be used to estimate the amount
of noise that can be expected on the output due to noise in the
switching power supply. As an example, consider a switching
power supply operating at 65.05 kHz, with peak–to–peak
noise levels of 10, 6, 3.3, 2.5, 2, and 1.4 mV for the fundamental and the first five harmonics, respectively. Assume the worst
case scenario, an almost perfect match of power supply fundamental frequency with the fundamental of the ASIC and all
noise signals in phase. The power supply noise that would be
seen at the output due to each harmonic would be calculated
as follows:
Harmonic
Aliasing Gain
P.S. Noise
Output Noise
Fundamental
0.4242
10.00 mV
4.24 mV
1st
0.3674
6.00 mV
2.20 mV
2nd
2.7116
3.33 mV
9.04 mV
3rd
0.6007
2.50 mV
1.50 mV
4th
3.2017
2.00 mV
6.40 mV
5th
0.7361
1.40 mV
1.03 mV
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The total output noise would be the sum of the individual
components:
Total Output Noise = (4.24 + 2.20 + 9.04 + 1.50 + 6.40
+ 1.03) mV
Total Output Noise = 24.41 mV peak–to–peak.
If this output signal were fed into an 8 bit A/D converter,
referenced to 5 V full scale, the worst case error due to power
supply noise would be equivalent to 1 bit count.
The error that can occur in the output due to aliasing gain
can be avoided very easily. The easiest method is to power the
part with a voltage regulator. Since the voltage regulator provides a clean, steady supply, the possibility of aliasing is eliminated. If the accelerometer is powered with a switching supply,
a filter should be placed on the power supply output to eliminate the noise of the harmonics. If placing a filter on the switching supply is not feasible, the user must ensure that the
operating frequency of the switching power supply is outside
the frequency ranges of the peaks shown in Figure 3. The plot
shown is a superposition of the response of the internal four
pole Bessel lowpass filter, scaled by the corresponding aliasing gain for each harmonic. The Bessel filter has the –3 dB
frequency at 400 Hz and, being of fourth order, has a very
steep roll–off outside the passband, with approximately
Freescale Semiconductor, Inc...
"
2–88
–80 dB of attenuation at 4 kHz. If a switching power supply
must be used, its operating frequency should be at least 800
Hz from the accelerometer’s sampling frequency. Any switching noise present will be aliased to 800 Hz or higher, where the
attenuation will be approximately –24 dB or lower, thus reducing the power supply induced noise below the part’s noise floor.
CONCLUSION
The MMA1201P accelerometer demonstrates Motorola’s
commitment to continuous product improvement. A new oscillator lowers the noise in the part and enables tighter control of
the –3 dB bandwidth of the internal lowpass filter. The supply
voltage is routed to the transducer and the DC level reference
of the capacitance–to–voltage converter stage through a
newly added filter, thus reducing the part’s susceptibility to
power supply noise. The capacitance–to–voltage converter
stage uses new signal conditioning methods, which virtually
eliminate ratiometric errors. The temperature compensation
for sensitivity is improved, producing a very flat response over
temperature. Overall the part offers much enhanced performance and is simpler to use. Equally important, Motorola’s
MMA1201P accelerometer has remained very price competitive, making it ideal for most applications requiring acceleration sensors.
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MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
Baseball Pitch Speedometer
AN1635
Prepared by: Carlos Miranda, Systems and Applications Engineer and
David Heeley, Systems and Applications Mechanical Engineer
Freescale Semiconductor, Inc...
INTRODUCTION
The Baseball Pitch Speedometer, in its simplest form, consists of a target with acceleration sensors mounted on it, an
MCU to process the sensors’ outputs and calculate the ball
speed, and a display to show the result. The actual implementation, shown in Figure 1, resembles a miniature pitching
cage, that can be used for training and/or entertainment. The
cage is approximately 6 ft. tall by 3 ft. wide by 6 ft. deep. The
upper portion is wrapped in a nylon net to retain the baseballs
as they rebound off the target. A natural rubber mat, backed
by a shock resistant acrylic plate, serve as the target. Accelerometers, used to sense the ball impact, and buffers, used to
drive the signal down the transmission line, are mounted on
the back side of the target. The remainder of the electronics
is contained in a display box on the top front side of the cage.
Accelerometers are sensors that measure the acceleration exerted on an object. They convert a physical quantity
into an electrical output signal. Because acceleration is a
vector quantity, defined by both magnitude and direction, an
accelerometer’s output signal typically has an offset voltage
and can swing positive and negative relative to the offset,
to account for both positive and negative acceleration. An
example acceleration profile is shown in Figure 2. Because
acceleration is defined as the rate of change of velocity with
respect to time, the integration of acceleration as a function
of time will yield a net change in velocity. By digitizing and
numerically integrating the output signal of an accelerometer
through the use of a microcontroller, the “area under the
curve” could be computed. The result corresponds to the net
change in velocity of the object under observation. This is the
basic principle behind the Baseball Pitch Speedometer.
Figure 1. David Heeley, mechanical designer of the Baseball Pitch Speedometer Demo,
tests his skills at Sensors Expo Boston ’97.
REV 1
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AN1635
CAPTURE
WINDOW
POINT
OF
IMPACT
THRESHOLD
LEVEL
Freescale Semiconductor, Inc...
A
B
OSCILLATIONS THAT RESULT
AS ENERGY IS DISSIPATED
SYSTEM AT STEADY RATE
Figure 2. Typical Crash Pattern for the Baseball Pitch Speedometer Demo
THEORY OF OPERATION
When a ball is thrown against the target, the accelerometer
senses the impact and produces an analog output signal,
proportional to the acceleration measured, resulting in a crash
signature. The amplitude and duration of the crash signature
is a function of the velocity of the ball. How can this crash
signature be correlated to the velocity of the baseball? By
making use of the principle of conservation of momentum (see
Equation 1). The principle of conservation of momentum
states that the total momentum within a closed system
remains constant. In our case, the system consists of the
thrown ball and the target.
mball *Vball,initial + mtarget *Vtarget,initial =
mball *Vball,final + mtarget *Vtarget,final
Eq. 1
When the ball is thrown, it has a momentum equivalent to
mball *Vball,initial. The target initially has zero momentum
since it is stationary. When the ball collides with the target,
part of the momentum of the ball is transferred to the target,
and the target will momentarily experience acceleration,
velocity, and some finite, though small, displacement before
dissipating the momentum and returning to a rest state. The
2–90
other portion of momentum is retained by the ball as it bounces
off the target, due to the elastic nature of the collision. By
measuring the acceleration imparted on the target, its velocity
is computed through integration. Ideally, if the mass of the ball,
the mass of the target, and the final velocity of the ball are
known, then the problem could be solved analytically and the
initial velocity of the baseball determined.
The analysis of the crash phenomenon is, however, actually
quite complex. Some factors that must be taken into account
and that complicate the analysis greatly, are the spring
constant and damping coefficient of the target. The target will
be displaced during impact because it is anchored to the frame
by a thick rubber mat. This action effectively causes the
system to have a certain amount of spring. Also, though the
mat is very dense, it will deform somewhat during impact and
will act as shock absorber. In addition, the ball itself also has
a spring constant and damping coefficient associated with it,
since it bounces off the target and, though not noticeable by
the naked eye, will deform during the impact. Finally, and of
even greater significance, the mass of the ball, the mass of the
target, and the final velocity of the ball are neither known nor
measured. So how can the system work?
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AN1635
repeatable. It also eliminated potential error caused by the
variability of location of impact on the target that would inevitably result from several manual throws. Figure 3 shows a
linear regression plot of the response of the system as a function of incident velocity. As is indicated by the plot, just a simple
constant of proportionality could be used to correlate the measured acceleration response to the incident velocity of the ball,
with fairly accurate results.
The Baseball Pitch Speedometer works by exploiting the
fact that the final velocity of the target will be, according to
Eq. 1, linearly proportional to the initial velocity of the thrown
ball. Therefore, by measuring the acceleration response of the
system to various ball velocities, which can be measured by
independent means such as a radar gun, the system could be
calibrated and a linear model developed. To facilitate the characterization and calibration of the system, a pitching machine
was used to ensure that the incident ball speed would be
14000
GRAND TOTAL AS RECORDED BY MCU
Freescale Semiconductor, Inc...
12000
10000
8000
Y
PREDICTED Y
6000
4000
2000
0
0
10
20
30
40
50
60
BASEBALL SPEED AS RECORDED BY RADAR GUN (mph)
Figure 3. Baseball Pitch Speedometer Characterization Data
IMPLEMENTATION — HARDWARE
The target mat of the Baseball Pitch Speedometer has an
area of approximately 9 ft2 (3 by 3). Even though the rubber
material used to construct the target is quite dense and
heavy, the transmission of an impact is very poor if the ball
strikes the target too far from the sensor. Therefore, to cover
Motorola Sensor Device Data
such a relatively large area it is necessary to use at least
four devices; one centered in each quadrant of the square
target. In addition, a shock resistant plate about a quarter
inch thick is mounted behind the rubber mat. These features
help make the response of the system more uniform and
reduce errors that result from the variability of where the ball
strikes the target.
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The bulk of the circuit hardware is contained in a display box
mounted on the top front side of the cage. Since the accelerometers are physically located far away from the mother
board (about 10 feet of wiring), op–amps were used to buffer
the accelerometers’ output and drive the transmission line.
The four accelerometer signals are then simultaneously fed
into a comparator network and four of the ADC inputs on an
MC68HC11 microcontroller. The MC68HC11 was selected
because it has the capability of converting four A/D channels
in one conversion sequence and operates at a higher clock
speed. These two features reduce the overall time interval
between digitizations of the analog signal (that result from the
minimum required time for proper A/D conversion and from
software latency) thus allowing a more accurate representation of the acceleration waveform to be captured. The
comparator network serves a similar purpose by eliminating
the additional software algorithm and execution time that
would be required to continually monitor the outputs of all four
accelerometers and determine whether impact has occurred
or not. By minimizing this delay (some is still present since the
output signal must exceed a threshold, and a finite amount of
time is required for this) more of the initial and more significant
part of the signal is captured.
The comparator network employs four LM311’s configured
to provide an OR function, and a single output is fed into an
input capture pin on the MCU. A potentiometer and filter
capacitor are used to provide a stable reference threshold
voltage to the comparator network. The threshold voltage is
set as close as possible to the accelerometers’ offset voltage
to minimize the delay between ball impact and the triggering
of the conversion sequence, but enough clearance must be
provided to prevent false triggering due to noise. Because the
comparator network is wired such that any one of the accelerometer outputs can trigger it, the threshold voltage must be
higher than the highest accelerometer offset voltage. Hysteresis is not necessary for the comparator network, because
2–92
once the MCU goes into the conversion sequence it ignores
the input capture pin.
The system is powered using a commercially available 9 V
supply. A Motorola MC7805 voltage regulator is used to provide a steady 5 Volt supply for the operation of the MCU, the
accelerometers, the comparator network, and the op–amp
buffers. The 9 V supply is directly connected to the common
anode 8–segment LED displays. Each segment can draw as
much as 30 mA of current. Therefore, to ensure proper operation, the power supply selected to build this circuit should be
capable of supplying at least 600 mA. Ports B and C on the
MCU are used to drive the LED displays. Each port output pin
is connected via a resistor to the base of a BJT, which has the
emitter tied to ground. A current limiting resistor is connected
between the collector of each BJT and the cathode of the
corresponding segment on the display. To minimize the
amount of board space consumed by the output driving circuitry, MPQ3904s (quad packaged 2N3904s) were selected
instead of the standard discrete 2N3904s. The zero bit on Port
C is connected to a combination BJT and MOSFET circuit that
drives the “Your Speed” and “Best Speed” LED’s. The circuit
is wired so that the LED’s toggle, and only one can be ON at
a time.
Figure 4 shows a schematic of the circuit used. Part (a)
shows the accelerometers, the op–amps used to buffer the
outputs and drive the transmission lines, the comparator network and the potentiometer used to set the detection threshold. Part (b) shows the MCU, with its minimal required
supporting circuitry. Part (c) shows the voltage regulator, a
mapping of the cathodes to the corresponding segments on
the LED displays, the BJT switch circuitry used to drive the
seven segment display LEDs (although not shown on the
schematic, this circuit block is actually repeated 15 times), and
finally, the circuitry used to drive the “Your Speed”/“Best
Speed” LEDs.
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AN1635
VCC
VCC
U1
VCC
ACCELEROMETER
VCC
4 ST
8 VDD
C1
0.1 mF
VOUT 5
R1
1 kΩ
C5
0.01 mF
7 VSS
3
2
+
R5
10 kΩ
6
U5
–
4
8
2 +
7
3 –
7
U9
1
4
MC33201
LM311
PA2/IC1
R6
1 kΩ
C9
0.01 mF
PE4/AN4
VCC
U2
VCC
ACCELEROMETER
Freescale Semiconductor, Inc...
VCC
C2
0.1 mF
4
ST
8
VDD
VOUT 5
R2
1 kΩ
C6
0.01 mF
7 VSS
3
2
+
6
U6
–
4
8
2 +
7
3 –
7
U10
1
4
MC33201
LM311
PE5/AN5
VCC
U3
VCC
ACCELEROMETER
VCC
C3
0.1 mF
4
ST
8
VDD
VOUT 5
R3
1 kΩ
C7
0.01 mF
7 VSS
3
2
+
6
U7
–
4
8
2 +
7
3 –
7
U11
1
4
MC33201
LM311
PE6/AN6
VCC
U4
VCC
ACCELEROMETER
VCC
C4
0.1 mF
4
ST
8
VDD
7 VSS
VOUT 5
R4
1 kΩ
C8
0.01 mF
3
2
+
6
U8
–
4
8
2 +
7
MC33201
3 –
7
U12
1
4
LM311
VCC
R7
20 kΩ
PE7/AN7
C10
1 mF
Figure 4a. Accelerometers, Buffer Op–Amps, and Comparator Network
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AN1635
U14
MC68HC11E9
VCC
E
26
VDD
C13
0.1 µF
C12
4.7 µF
1
7
10 M Ω
R11
8
VSS
EXTAL
XTAL
Freescale Semiconductor, Inc...
8 MHz
C15
C14
VCC
18 pF
18 pF
VCC
PA0/IC3
PA1/IC2
PA2/IC1
PA3/IC4/OC5/OC1
PA4/OC4/OC1
PA5/OC3/OC1
PA6/OC2/OC1
PA7/PAI/OC1
PB0/A8
PB1/A9
PB2/A10
PB3/A11
PB4/A12
PB5/A13
PB6/A14
PB7/A15
STRB/R/W*
R10
R8
4.7 k Ω
17
RESET*
4.7 kΩ
U13
VCC
MC34164P
2
IN
RST*
1
R12
GND
R13
4.7 k Ω
18
4.7 k Ω
19
3
4.7 k Ω
R14
R9
200 k Ω
C11
1 µF
2
3
RESET
XIRQ*
IRQ*
MODB/VSTBY
MODA/LIR*
VCC
R15
1 kΩ
52
C16
1 µF
51
VRH
VRL
STRA/AS
PC0/AD0
PC1/AD1
PC2/AD2
PC3/AD3
PC4/AD4
PC5/AD5
PC6/AD6
PC7/AD7
PD0/RxD
PD1/TxD
PD2/MISO
PD3/MOSI
PD4/SCK
PD5/SS*
PE0/AN0
PE1/AN1
PE2/AN2
PE3/AN3
PE4/AN4
PE5/AN5
PE6/AN6
PE7/AN7
5
34
33
32
31
30
29
28
27
42
41
40
39
38
37
36
35
PA2/IC1
“Your’’ / “Best’’
F
G
E
D
Ones Digit
C
LED Display
B
A
6
4
9
10
11
12
13
14
15
16
DP
F
G
E
D
C
B
A
Tens Digit
LED Display
20
21
22
23
24
25
43
45
47
49
44
46
48
50
PE4/AN4
PE5/AN5
PE6/AN6
PE7/AN7
Figure 4b. MC68HC11E9 MCU with Supporting Circuitry
2–94
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B+
U15
3
+9 VDC P.S.
MC78L05ACP
VIN
C17
1µF
1
VOUT
VCC
C18
1µF
GND
2
GND P.S.
B+
A
1/8 LED Display
Freescale Semiconductor, Inc...
F
B
R32 – R46
180 Ω
G
E
R16 – R30
10 k Ω
C
D
U16–U19 MPQ3904
From PB or PC
DP
VCC
“Best Speed’’
VCC
“Your Speed’’
R48
1 kΩ
R47
1 kΩ
U20 VN0300L
R31
10 k Ω
PB0
1/4 MPQ3094
Figure 4c. Voltage Regulator, LED Segment Mapping, and LED Driving Circuitry
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Freescale Semiconductor, Inc...
IMPLEMENTATION — SOFTWARE
The operation of the Baseball Pitch Speedometer is very
simple. Upon power on reset, the output LEDs are initialized
to display “00” and “Best Speed.” The analog to digital converter is turned on and the offset voltages of the accelerometers are measured and stored. Finally, all the variables are
initialized and the MCU goes into a dormant state, where it will
wait for a negative edge input capture pulse to trigger it to
begin processing the crash signal.
Once the input capture flag is set, the MCU will immediately
begin the analog to digital conversion sequence. As it digitizes
the crash signature, it will calculate the absolute difference
between the current value and the stored offset voltage value.
It will integrate by summing up all the differences. Figure 2
shows a typical crash signature of the Baseball Pitch
Speedometer. As illustrated, starting at the point of impact (A),
the acceleration will initially ramp up, reaching a maximum,
then decrease as the target is displaced. Because the target
is constrained to the frame structure, the acceleration will
continue to decrease until it reaches a minimum (point B),
which correspond to the travel stop of the target. It is difficult
to determine exactly when point B will occur, because the
amplitude and duration of the initial acceleration pulse will vary
with ball speed. Therefore, the capture window duration is set
so that it will encompass most typical crash signatures, while
rejecting most of the secondary ripples that result as the
energy is dissipated by the system.
After integrating the four signals, the results are added
together to produce an overall sum. This procedure averages
out the individual responses and reduces measurement error
due to the variability of where the ball lands on the target. The
MCU then divides the grand sum by an empirically predetermined constant of proportionality. The result will then go
through a binary to BCD conversion algorithm. A look–up table
is used to match the BCD numbers to their corresponding
7–segment display codes. The calculated speed is displayed
on the two digit 8–segment displays (one segment corresponds to the decimal point), and the “Your Speed” LED is
2–96
turned on while the “Best Speed” LED is turned off. After a
duration of approximately five seconds, the LEDs are toggled
and stored best speed is redisplayed. The five second delay
is used to provide enough time for the user to check his/her
speed and also to allow the target to return to a rest state. The
system is now ready for another pitch. A complete listing of the
software is presented in the Appendix.
CONCLUSION
The Baseball Pitch Speedometer works fairly well, with an
accuracy of +/– 5 mph. The dynamic range of the system is
also worthy of note, measuring speeds from less than 10 mph
up to well above the 70 mph range. One key point to emphasize, is that the system is empirically calibrated, and so to
maintain good accuracy the system should only be used with
balls of mass equal to those used during calibration.
Although intended mainly for training and recreational purposes, the Baseball Pitch Speedometer demonstrates a very
important concept concerning the use of accelerometers.
Accelerometers can be used not only to detect that an event
such as impact or motion has occurred, but more importantly
they measure the intensity of such events. They can be used
to discern between different crash levels and durations. This
is very useful in applications where it is desired to have the
system respond in accord with the magnitude of the input
being monitored. An example application would be a smart
air bag system, where the speed at which the bag inflates is
proportional to the severity of the crash. The deployment rate
of the airbag would be controlled so that it does not throw the
occupant back against the seat, thus minimizing the possibility of injury to the occupant. Another application where this
concept may be utilized is in car alarms, where the response
may range from an increased state of readiness and monitoring, to a full alarm sequence depending on the intensity of the
shock sensed by the accelerometer. This could be used to
prevent unnecessary firing of the alarm in the event that an
animal or person were to inadvertently bump or brush against
the automobile.
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AN1635
APPENDIX — ASSEMBLY CODE LISTING FOR BASEBALL PITCH SPEEDOMETER
Freescale Semiconductor, Inc...
* Baseball Pitch Speedometer – Rev. 1.0
*
* Program waits for detection of impact via the input capture pin and then reads four A/D channels.
* The area under the Acceleration vs. Time curve is found by subtracting the steady state offsets
* from the digitized readings and summing the results. The sum is then divided by an empirically
* determined constant of proportionality, and the speed of the ball is displayed.
*
* Written by Carlos Miranda
* Systems and Applications
* Sensor Products Division
* Motorola Semiconductor Products Sector
* May 6, 1997
*
*
********************************************************************************************************
*
Although the information contained herein, as well as any information provided relative
*
*
thereto, has been carefully reviewed and is believed accurate, Motorola assumes no
*
*
liability arising out of its application or use, neither does it convey any license under
*
*
its patent rights nor the rights of others.
*
********************************************************************************************************
* These equates assign memory addresses to variables.
EEPROM
EQU
$B600
CODEBGN
EQU
$B60D
REGOFF
EQU
$1000
;Offset to access registers beyond direct addressing range.
PORTC
EQU
$03
PORTB
EQU
$04
DDRC
EQU
$07
TCTL2
EQU
$21
TFLG1
EQU
$23
ADCTL
EQU
$30
ADR1
EQU
$31
ADR2
EQU
$32
ADR3
EQU
$33
ADR4
EQU
$34
OPTION
EQU
$39
STACK
EQU
$01FF
;Starting address for the Stack Pointer.
RAM
EQU
$0000
* These equates assign specific masks to variables to facilitate bit setting, clearing, etc.
ADPU
EQU
$80
;Power up the analog to digital converter circuitry.
CSEL
EQU
$40
;Select the internal system clock.
CCF
EQU
$80
;Conversion complete flag.
IC1F
EQU
$04
;Input Capture 1 flag.
IC1FLE
EQU
$20
;Configure Input Capture 1 to detect falling edges only.
IC1FCLR
EQU
$FB
;Clear the Input Capture 1 flag.
CHNLS47
EQU
$14
;Select channels 4 through 7 with MULT option ON.
SAMPLES
EQU
$0200
;Number of A/D samples taken.
OC1F
EQU
$80
;Output Compare 1 flag.
OC1FCLR
EQU
$7F
;Clear the Output Compare flag.
CURDLY
EQU
$0098
;Timer cycles to create delay for displaying ”Your Speed.”
RAMBYTS
EQU
$19
;Number of RAM variables to clear during initialization.
ALLONES
EQU
$FF
YOURSPD
EQU
$01
PRPFCTR
EQU
$00AD
;This constant of proportionality was empirically determined.
* Variables used for computation.
ORG
RAM
OFFSET1
RMB
1
;One for each accelerometer.
OFFSET2
RMB
1
OFFSET3
RMB
1
OFFSET4
RMB
1
SUM1
RMB
2
;Area under the acceleration vs. time curve.
SUM2
RMB
2
SUM3
RMB
2
SUM4
RMB
2
GRNDSUM
RMB
2
COUNT
RMB
2
CURBIN
RMB
1
TEMPBIN
RMB
1
BCD
RMB
2
CURDSPL
RMB
2
MAXBIN
RMB
1
MAXDSPL
RMB
2
* LED seven segment display patterns table.
ORG
EEPROM
JMP
START
SEVSEG
FCB
%11111010
FCB
%01100000
FCB
%11011100
FCB
%11110100
FCB
%01100110
FCB
%10110110
FCB
%10111110
FCB
%11100000
FCB
%11111110
FCB
%11100110
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Freescale Semiconductor, Inc.
* This is the main program loop.
ORG
CODEBGN
START
LDS
#STACK
LDX
#REGOFF
JSR
LEDINIT
JSR
ADCINIT
JSR
VARINIT
MAIN
JSR
CAPTURE
JSR
COMPUTE
JSR
BINTBCD
JSR
OUTPUT
BRA
MAIN
* This subroutine initializes ports B & C, and the LED display.
LEDINIT
PSHX
PSHA
LDX
#REGOFF
BSET
DDRC,X,ALLONES
;Configure port C as an output.
LDAA
SEVSEG
STAA
PORTB,X
STAA
PORTC,X
PULA
PULX
RTS
* This subroutine initializes the analog to digital converter.
ADCINIT
PSHX
PSHA
LDX
#REGOFF
BSET
OPTION,X,ADPU
;Turn on A/D converter via ADPU bit.
BCLR
OPTION,X,CSEL
;Select system e clock via CSEL bit.
CLRA
DELAY
INCA
BNE
DELAY
PULA
PULX
RTS
* This subroutine clears all the memory variables.
VARINIT
PSHX
LDX
#$0000
CLRVAR
CLR
OFFSET1,X
INX
CPX
#RAMBYTS
;Number of RMB bytes.
BLO
CLRVAR
DONECLR
LDX
#REGOFF
LDAA
#CHNLS47
;Measure the offset.
STAA
ADCTL,X
OFSWAIT
BRCLR
ADCTL,X,CCF,OFSWAIT
LDD
ADR1,X
STD
OFFSET1
LDD
ADR3,X
STD
OFFSET3
PULX
RTS
* This subroutine waits for impact and computes the area under the curve.
CAPTURE
PSHX
PSHA
PSHB
LDX
#REGOFF
BSET
TCTL2,X,IC1FLE
;Set IC1 to detect falling edge only.
BCLR
TFLG1,X,IC1FCLR
MONITOR
BRCLR
TFLG1,X,IC1F,MONITOR
ADCREAD
LDAA
#CHNLS47
;Select channels 4 – 7 for conversion.
STAA
ADCTL,X
ADCWAIT
BRCLR
ADCTL,X,CCF,ADCWAIT
CALDLT1
LDAB
ADR1,X
SUBB
OFFSET1
BPL
ADDSUM1
COMB
INCB
ADDSUM1
CLRA
ADDD
SUM1
STD
SUM1
CALDLT2
LDAB
ADR2,X
SUBB
OFFSET2
BPL
ADDSUM2
COMB
INCB
ADDSUM2
CLRA
ADDD
SUM2
STD
SUM2
CALDLT3
LDAB
ADR3,X
SUBB
OFFSET3
BPL
ADDSUM3
COMB
INCB
2–98
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ADDSUM3
CLRA
ADDD
SUM3
STD
SUM3
CALDLT4
LDAB
ADR4,X
SUBB
OFFSET4
BPL
ADDSUM4
COMB
INCB
ADDSUM4
CLRA
ADDD
SUM4
STD
SUM4
LDD
COUNT
ADDD
#$0001
STD
COUNT
CPD
#SAMPLES
BLO
ADCREAD
PULB
PULA
PULX
RTS
* This subroutine computes the ball speed by dividing the overall sum by a constant.
COMPUTE
PSHX
PSHA
PSHB
LDD
SUM1
ADDD
SUM2
ADDD
SUM3
ADDD
SUM4
STD
GRNDSUM
LDX
#PRPFCTR
IDIV
XGDX
STAB
CURBIN
PULB
PULA
PULX
RTS
* This subroutine converts from binary to BCD. (Limited to number up to 99 decimal.)
BINTBCD
PSHX
PSHA
PSHB
LDX
#$0000
LDAA
CURBIN
STAA
TEMPBIN
CLRA
CLRB
BINSHFT
LSL
TEMPBIN
ROLB
LSLA
CMPB
#$10
BLO
CHKDONE
INCA
ANDB
#$0F
CHKDONE
INX
CPX
#$0008
BEQ
RAILAT9
CHKFIVE
CMPB
#$05
BLO
BINSHFT
ADDB
#$03
BRA
BINSHFT
RAILAT9
CMPA
#$09
;Force the display to “99” if speed > 100 mph.
BLS
DONE
LDD
#$0909
DONE
STD
BCD
LDX
#SEVSEG
;This part finds the seven segment display codes.
XGDX
ADDB
BCD
XGDX
LDAA
$00,X
STAA
CURDSPL
LDX
#SEVSEG
XGDX
ADDB
BCD+1
XGDX
LDAA
$00,X
STAA
CURDSPL+1
PULB
PULA
PULX
RTS
* This subroutine displays the current speed for 5 seconds & then displays the maximum.
OUTPUT
PSHX
PSHA
PSHB
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AN1635
OLDMAX
LEDWAIT
DSPLDLY
Freescale Semiconductor, Inc...
RECLEAR
2–100
LDX
LDAA
CMPA
BLS
STAA
LDD
STD
LDD
STD
BSET
LDD
BCLR
BRCLR
ADDD
CPD
BLO
LDX
CLR
INX
CPX
BLO
LDX
LDD
STD
PULB
PULA
PULX
RTS
#REGOFF
CURBIN
MAXBIN
OLDMAX
MAXBIN
CURDSPL
MAXDSPL
CURDSPL
PORTC,X
PORTB,X,YOURSPD
;Toggle the ”YOUR”/“BEST” LEDs.
#$0000
TFLG1,X,OC1FCLR
;Clear output compare 1 flag.
TFLG1,X,OC1F,DSPLDLY
#$0001
#CURDLY
;Decimal 152. (152 * 33ms = 5.0 sec)
LEDWAIT
#$0000
SUM1,X
;Clear 12 RAM bytes beginning at address ”SUM1”.
;Clears SUM1 thru SUM4, GRNDSUM, and COUNT.
#$000C
RECLEAR
#REGOFF
MAXDSPL
PORTC,X
;The ”YOUR”/“BEST” LEDS are automatically toggled.
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Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
AN1640
Reducing Accelerometer Susceptibility to BCI
Freescale Semiconductor, Inc...
Prepared by Brandon Loggins
Automobile manufacturers require all system electronics to
pass stringent electromagnetic compatibility (EMC) tests.
Airbag systems are one of the systems that must perform
adequately under EMC tests. There are different types of tests
for EMC, one of which is testing the tolerance of the system
to high frequency conducted emissions. One of the most
stringent methods for EMC evaluation is the Bulk Current
Injection (BCI) test. The entire airbag system must continue to
function normally throughout the BCI test. This application
note will discuss how to reduce susceptibility to BCI for the
Motorola accelerometer but the information presented here
can be applied to other electronic components in the system.
BCI TEST SETUP
The BCI test procedure follows a published SAE engineering
standard, “Immunity to Radiated Electric Fields ~ Bulk Current
Injection (BCI)”, or SAE J 1113/401. For an airbag module, this
involves injecting the desired current into the wiring harness by
controlling current in the injection probe. The test frequency can
vary from one to several hundred MHz. There are at least 20
frequency steps per octave required for the test, but as many
as 50 steps per octave can be used. The injection probe is
placed on the harness in one of three distances from the airbag
module connector: 120, 450 and 750 mm. There is a monitor
pickup probe present to measure the amount of current being
injected. It is placed 50 mm from the airbag module. This feeds
back to the system to ensure that the desired test current is
being injected on to the wiring harness. Figure 1 shows the
setup for the BCI test. (For more details, see the SAE J
1113/401 Test Procedure).
70, 450, or 750 mm
ANECHOIC CHAMBER WALL
50 mm
AIRBAG
MODULE
WIRING HARNESS
PC
LOAD BOX
PICKUP
PROBE
INJECTION
PROBE
BASEPLATE CONNECTED
TO GROUND
Figure 1. BCI Test Setup
The harness connects the airbag module to a load box. This
load box provides simulated loads for terminating the
remainder of the airbag system (firing ignitors, etc.). The data
coming back is translated from J1850 to RS232 to be
communicated to a dummy terminal on a PC. For safety
reasons, this test is typically performed inside an anechoic
chamber to shield high frequency emissions from equipment
and humans.
BCI TEST PROCEDURE FOR THE
MMA2202D ACCELEROMETER
The accelerometer is evaluated in the following manner. In
an airbag system, the microcontroller’s A/D converter digitizes
the accelerometer output. The microcontroller sends this
value to the communication ASIC which translates the logic
from board level logic to RS232, then sends the value back
REV 2
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AN1640
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along the wiring harness. Once through the chamber wall, the
data is translated to RS232 and fed to a dummy terminal. On
the terminal screen, the A/D codes for the accelerometer can
be monitored for unexpected performance.
Ideally, when the accelerometer is at rest (no acceleration
applied), the output should be at 0g, regardless of what EMC
testing the system may be subjected to. Depending on the
crash algorithm of the airbag module software, there is some
allowable offset shift that can be tolerated. Higher shift in
output could create errors in the crash analysis software,
perhaps causing the airbags to unnecessarily deploy when
there is not a crash or not deploy when there is a crash.
The Motorola accelerometer must be able to meet the
airbag system requirements throughout BCI exposure. It has
a sensitivity of 40 mV/g and an offset (0g output) of 2.50 V.
During the BCI test, the accelerometer output should be
2.50 V at 0g with as little drift as possible. A typical airbag
system may have software that can tolerate from as little as
0.5 g up to 2.0 g. of deviation from the offset. The system would
then expect the accelerometer output to be within 40 mV of the
offset during the entire BCI test. Therefore, at any given
frequency of the BCI test, if the output deviates outside this
expected window of drift, it fails the test.
MMA2202D ACCELEROMETER BCI TEST
RESULTS
If a system has not been well designed for electromagnetic
compatibility, the accelerometer, as well as other devices, can
have performance problems. What has been found for the
accelerometer is that in some system applications, it suffers
from an offset shift when certain frequencies of BCI are
applied. For example, in one airbag system being tested at a
certain frequency, with the desired BCI current applied, the
offset is found to shift down by 60 mV. This would equate to an
error of 1.5 g. See Figure 2. At other frequencies, this shift is
even higher. This DC shift plot was taken with an oscilloscope
using a 20 MHz filter to remove the high frequency component
of the signal. Probes are placed at the accelerometer in the
system application. The plot shows the accelerometer output
before and after BCI was applied (before and after the RF
generator creating the high frequency signal was turned on).
ACCELEROMETER VOUT
w/o BCI
ACCELEROMETER VOUT
w/BCI
VCC
Figure 2. Accelerometer Tested Under High Frequency BCI
This phenomenon has been determined to be system level
related. PCB layout and grounding for the accelerometer will
affect its performance. This was found by testing the
accelerometer outside of the airbag module. The device was
put on a test board by itself with only the supply decoupling
capacitor of 0.1 µF connected to it. To simulate the effect of
BCI on Vcc, a frequency generator was used to inject a known
high frequency sinusoid that caused BCI failure on to the 5.0 V
supply voltage. The device was first tested in small test board
with ground provided by one wire back to the supply. This
grounding reproduced the failure due to BCI seen at the
2–102
module level. The test board was then mounted down to a
ground plane provided by a copper plate and the
accelerometer ground was soldered to the plate (providing a
low impedance path to ground). With this setup, the offset shift
did not occur.
If a system does not incorporate a good PCB layout
providing a low impedance to ground, the accelerometer
output may shift at certain high frequencies. This output offset
shift was caused by a shift in the 0–5 V supply window.
Because the accelerometer has a ratiometric output, its offset
is dependent on the supply voltage. Any change in the supply
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voltage will result in the same proportional change in the
output. For example, if the 5 V supply were to change by 10%,
from 5.0 V to 5.5 V, the accelerometer offset will change by
10% also, from 2.5 V to 2.75 V. This phenomena would also
occur if the ground were to shift. A 100 mV change in ground
would result in a 50 mV change in the output. If the
accelerometer does not have low impedance path to ground
and parasitics from a poor ground are present as a result, the
ground seen by the accelerometer may change over
frequency. So, during a BCI test, if the 5.0 V supply does not
shift but the output of the accelerometer does, the ground to
the accelerometer may be moving.
It was found with some experimentation that the offset shift
can be eliminated with proper board layout techniques as
described below.
Freescale Semiconductor, Inc...
PROPER LAYOUT TECHNIQUES
Since the Motorola accelerometer is a sensitive analog
device that relies on a clean supply to function within
established parameters, there are some techniques that can
be employed to minimize the effects of BCI on the
accelerometer performance. PCB layout is paramount to
reducing susceptibility to BCI.
• A low impedance path to ground will provide shunting of the
high frequency interference and minimize its effect on the
accelerometer. The best way to provide a good path is by
putting a solid, unbroken ground plane in the PCB. This
ground plane should be shunted to chassis ground at the
module connector. This will ensure that the high frequency
BCI will be shunted before interfering with accelerometer
performance.
• All accelerometer pins that require ground connection
should be tied together to a common ground.
• Traces attached directly to the connector pins can receive
high RF noise, which can couple to nearby traces and components. Increasing series impedance of the traces helps
reduce the couple or conducted noise. High frequency filters on the supply line and other susceptible lines may be
required to filter out high frequency interference introduced
by the BCI test. Signal lines that carry low current can tolerate series resistances of 100–200 Ω.
• Decoupling capacitors on every input line to the common
ground plane will help shunt the high frequency away from
the system. These should be placed near the connector.
Motorola Sensor Device Data
AN1640
• Signal trace lengths to and from the accelerometer should
be kept at a minimum. The shorter the trace, the less
chance it has of picking up high frequency BCI signals as
it crosses the board. Trace lengths can be reduced by placing the accelerometer and the microcontroller as close
together as possible. Signal and ground traces looping
should be minimized.
• A decoupling capacitor on the accelerometer Vcc pin will
also help minimize BCI effects. The recommended value is
0.1 µF. This capacitor should be placed as close as possible to the accelerometer to achieve the best results.
• To maximize ratiometricity, the accelerometer Vcc and the
microcontroller A/D reference pin should be on the same
trace. The accelerometer ground and the microcontroller
ground should also share the same ground point. Therefore, when there is signal interference due to BCI, the A/D
converter and the accelerometer will see the interference
at the same level. This will result in the same digital code
representation of acceleration without signal interference.
• A clean power supply to both the accelerometer and the
microcontroller should be provided. Supply traces should
avoid high current traces that might carry high RF currents
during the BCI test. The traces should be as short as
possible.
• The accelerometer should be placed on the opposite end
of the PCB away from the connector. The farther the distance, the lower the chance high frequency RF from BCI
will interfere with the accelerometer.
• The accelerometer should be placed away from high current paths that may carry high RF currents during the BCI
test.
Automotive customers will continue to require airbag
systems to have high standards for EMC. One way to test for
EMC is perform the Bulk Current Injection test. Because of the
high current involved, BCI is one of the most difficult EMC tests
to pass. Being part of the airbag system, the accelerometer
must continue to function normally under application of high
frequency BCI. The accelerometer is highly sensitive to
placement on the board and its connection to ground. Poor
design will caused the device to fail the BCI test. The practice
of good PCB layout, device placement and good grounding
will allow the accelerometer to function within specification
and pass the BCI test.
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MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
AN1925
Using the Motorola Accelerometer
Evaluation Board
Prepared by: Leticia Gomez and Raul Figueroa
Sensor Products Division
Systems and Applications Engineering
Freescale Semiconductor, Inc...
INTRODUCTION
This application note describes the Motorola Accelerometer
Evaluation Board (Figure 1). The Accelerometer Evaluation
Board is a small circuit board intended to serve as an aid in
system design with the capability for mounting the following
devices: MMA1220D, MMA1201P, MMA1200D, MMA2201D.
This evaluation board is useful for quickly evaluating any of
these three devices. It also provides a means for
understanding the best mounting position and location of an
accelerometer in your product.
CIRCUIT DESCRIPTION
Figure 2 is a circuit schematic of the evaluation board. The
recommended decoupling capacitor at the power source and
recommended RC filter at the output, are included on the
evaluation board. This RC filter at the output of the
accelerometer minimizes clock noise that may be present
from the switched capacitor filter circuit. No additional
components are necessary to use the evaluation board.
Refer to the respective datasheet of the device being used
for specifications and technical operation of the
accelerometer.
The evaluation board has a 4–pin header (J1 in Figure 1) for
interfacing to a 5 volt power source or a 9 to 15 volt power
Jumper (JP1)
Mounting
Hole (1 of 4)
source (for example, 9 V battery). Jumper JP1 (see Figure 1)
must have the following placement: on PS if a 5 V supply is
being used or on BATT if a 9 V to 15 V supply is used. A 5 V
regulator (U1 in figure 1) supplies the necessary power for the
accelerometer in the BATT option.
The power header also provides a means for connecting to
the accelerometer analog output through a wire to another
breadboard or system. Four through–hole sockets are
included to allow access to the following signals: VDD, GND,
ST and STATUS. These sockets can be used as test points or
as means for connecting to other hardware.
The ON/OFF switch (S1) provides power to the
accelerometer and helps preserve battery life if a battery is
being used as the power source. S1 must be set towards the
“ON” position for the accelerometer to function. The green
LED (D1) is lit when power is supplied to the accelerometer.
A self–test pushbutton (S2) on the evaluation board is a
self–test feature that provides verification of the mechanical
and electrical integrity of the accelerometer. The STATUS pin
is an output from the fault latch and is set high if one of the fault
conditions exists. A second pressing of the pushbutton (S2)
resets the fault latch, unless of course one or more fault
conditions continue to exist.
5 V Regulator
(U1)
PS
Power Header
(J1)
MMA Device
Accelerometer Output
(Vout)
STATUS
On/Off Switch
(S1)
Self–Test
Pushbutton (S2)
BATT
Test Points
Power LED (D1)
Figure 1. Motorola Accelerometer Evaluation Board
REV 0
2–104
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Freescale Semiconductor, Inc.
AN1925
VDD
MMA1220D
S2
MC78L05
4
3
9 V to 15 V
J1
1
IN
.1 F
C1
OUT
GND
2
ST
VOUT
.33 F
C2
ON
VDD
+5 V
J1
PS
S1
JP1
VDD
.01 F
C3
750
R1
5
STATUS
VOUT
1K
R2
8
BATT
OFF
VOUT
J1
.01 F
C4
TP3
6 STATUS
TP2
VSS
7
D1
Green LED
Freescale Semiconductor, Inc...
Figure 2. Evaluation Board Circuit Schematic
SOIC
MMA Device
Unused pins
20–pin
Test Socket
Bottom Lid Snap
Pin 1
Figure 3. Motorola Accelerometer Evaluation Board with Test Socket
The board allows for direct mounting of a 16–pin DIP or
SOIC package. For the SOIC device, a 20–pin test socket is
used to allow for evaluation of more than one device without
soldering directly to the board and potentially damaging the
PCB. Care must be taken in placing the device correctly in the
socket as four pins of the socket will not be used. With the
board oriented as shown in Figure 3, Pin 1 should face
downward and the device should be positioned toward the top
of the test socket, thereby exposing the bottom four pins of the
test socket. The socket is marked to help identify the 4 unused
socket pins. Lids to secure the device in the socket are
included with the board and delicately snap into place. The lids
Motorola Sensor Device Data
can be removed by applying pressure to the sides of the lid or
by lifting the top and bottom snaps of the lid.
PIN OUT DESCRIPTION
Pin
Name
Description
4
ST
5
VOUT
6
STATUS
7
VSS
Power supply ground
8
VDD
Power supply input
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Logic input pin to initiate self–test
Output voltage of the accelerometer
Logic output pin to indicate fault
2–105
AN1925
Freescale Semiconductor, Inc.
Figures 4 and 5 show the layout used on the evaluation
board. Through–hole mounting components have been
selected to facilitate component replacement.
It is important to maintain a secure mounting scheme to
capture the true motion.
Orientation of the sensor is also crucial. For best results,
align the sensitive axis of the accelerometer to the axis of
vibration. In the case of the MMA1220D, the sensitive axis is
perpendicular to the plane of the evaluation board.
MOUNTING CONSIDERATIONS
SUMMARY
System design and sensor mounting can affect the
response of a sensor system. The placement of the sensor
itself is critical to obtaining the desired measurements. It is
important that the sensor be mounted as rigidly as possible to
obtain accurate results. Since the thickness and mounting of
the board varies, parasitic resonance may distort the sensor
measurement. Hence, it is vital to fasten and secure to the
largest mass structure of the system, i.e. the largest truss, the
largest mass, the point closest to source of vibration. On the
other hand, dampening of the sensor device can absorb much
of the vibration and give false readings as well. The evaluation
board has holes on the four corners of the board for mounting.
The Accelerometer Evaluation Board is a design–in tool for
customers seeking to quickly evaluate an accelerometer in
terms of output signal, device orientation, and mounting
considerations. Both through–hole and surface mount
packages can be evaluated. With the battery supply option
and corner perforations, the board can easily be mounted on
the end product; such as a motor or a piece of equipment.
Easy access to the main pins allows for effortless interfacing
to a microcontroller or other system electronics. The simplicity
of this evaluation board provides reduced development time
and assists in selecting the best accelerometer for the
application.
Freescale Semiconductor, Inc...
BOARD LAYOUT AND CONTENT
Figure 4. Board Layout (Component Side)
2–106
Figure 5. Board Layout (Back Side)
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Case Outlines
A
A
G/2
2 PLACES, 16 TIPS
G
16
NOTES:
1. ALL DIMENSIONS ARE IN MILLIMETERS.
2. INTERPRET DIMENSIONS AND TOLERANCES
PER ASME Y14.5M, 1994.
3. DIMENSIONS ”A” AND ”B” DO NOT INCLUDE
MOLD FLASH OR PROTRUSIONS. MOLD FLASH
OR PROTRUSIONS SHALL NOT EXCEED 0.15
PER SIDE.
4. DIMENSION ”D” DOES NOT INCLUDE DAMBAR
PROTRUSION. PROTRUSIONS SHALL NOT
CAUSE THE LEAD WIDTH TO EXCEED 0.75
0.15 T A B
9
B
P
1
B
8
16X
D
0.13
T A B
M
Freescale Semiconductor, Inc...
R
X 45 _
J
C
0.1
K
T
DIM
A
B
C
D
F
G
J
K
M
P
R
M
F
SEATING
PLANE
CASE 475–01
ISSUE B
16 LEAD SOIC
–A–
20
11
P10 PL
0.13 (0.005)
–B–
1
M
T A
M
B
M
10
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETER.
3. DIMENSIONS A AND B DO NOT INCLUDE MOLD
PROTRUSION.
4. MAXIMUM MOLD PROTRUSION 0.15 (0.006) PER
SIDE.
5. DIMENSION D DOES NOT INCLUDE DAMBAR
PROTRUSION. ALLOWABLE DAMBAR
PROTRUSION SHALL BE 0.13 (0.005) TOTAL IN
EXCESS OF D DIMENSION AT MAXIMUM
MATERIAL CONDITION.
D 16 PL
0.13 (0.005)
M
T A
M
B
M
R
X 45 _
J
C
–T–
SEATING
PLANE
MILLIMETERS
MIN
MAX
10.15
10.45
7.40
7.60
3.30
3.55
0.35
0.49
0.76
1.14
1.27 BSC
0.25
0.32
0.10
0.25
0_
7_
10.16
10.67
0.25
0.75
K
G
F
M
DIM
A
B
C
D
F
G
J
K
M
P
R
MILLIMETERS
MIN
MAX
12.67
12.96
7.40
7.60
3.30
3.55
0.35
0.49
0.76
1.14
1.27 BSC
0.25
0.32
0.10
0.25
0_
7_
10.16
10.67
0.25
0.75
INCHES
MIN
MAX
0.499
0.510
0.292
0.299
0.130
0.140
0.014
0.019
0.030
0.045
0.050 BSC
0.010
0.012
0.004
0.009
0_
7_
0.400
0.420
0.010
0.029
CASE 475A–01
ISSUE O
20 LEAD SOIC
Motorola Sensor Device Data
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A
B
A
12
C
Y
7
NOTES:
1. DIMENSIONS ARE IN INCHES.
2. INTERPRET DIMENSIONS AND TOLERANCES
PER ASME Y14.5M–1994.
3. PLANE –X– AND PLANE –Y– SHOULD BE
ALIGNED WITHIN 0.0015”.
B
1
8X
8X
J
D
T A M
6X
U
0.005
G
M
DIM
A
B
C
D
G
H
J
K
L
M
N
P
S
U
L
K
U
H
M
"
Y
6
S
B
N
M
T
CASE 456–06
ISSUE J
WB PACKAGE
A
C
N
F
T
E
G
16X
0.005 (0.13)
2–108
M
SEATING
PLANE
0.005 (0.13)
J
8
16X
1
L
9
B
16
M
M
T B
B
A
K
Freescale Semiconductor, Inc...
P
INCHES
MIN
MAX
0.618
0.638
0.240
0.260
0.127
0.133
0.015
0.021
0.100 BSC
0.050 BSC
0.009
0.012
0.125
0.140
0.063
0.070
0.015
0.025
0.036
0.044
0.095
0.110
0.025
0.035
0.088
0.108
NOTES:
1. DIMENSIONING AND TOLERANCING PER ASME
Y14.5M, 1994.
2. CONTROLLING DIMENSION: INCH.
3. DIMENSION L TO CENTER OF LEADS WHEN
FORMED PARALLEL.
4. DIMENSION B DOES NOT INCLUDE MOLD FLASH.
DIM
A
B
C
D
E
F
G
J
K
L
M
N
INCHES
MIN
MAX
0.744
0.783
0.240
0.260
0.145
0.185
0.015
0.021
0.050 BSC
0.040
0.70
0.100 BSC
0.008
0.015
0.115
0.135
0.300 BSC
0_
10_
0.015
0.040
MILLIMETERS
MIN
MAX
18.90
19.90
6.10
6.60
3.69
4.69
0.38
0.53
1.27 BSC
1.02
1.78
2.54 BSC
0.20
0.38
2.92
3.43
7.62 BSC
0_
10_
0.39
1.01
D
T A
CASE 648C–04
ISSUE D
DIP PACKAGE
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Accelerometer Glossary of Terms
Acceleration
Change in velocity per unit time.
Acceleration Vector
Vector describing the net acceleration acting upon the device.
Frequency Bandwidth
The accelerometer output frequency range.
g
A unit of acceleration equal to the average force of gravity occurring at the earth’s surface.
A g is approximately equal to 32.17 ft/s2 or 9.807 m/s2.
Nonlinearity
The maximum deviation of the accelerometer output from a point–to–point straight line
fitted to a plot of acceleration vs. output voltage. This is determined as the percentage of
the full–scale output (FSO) voltage at full–scale acceleration (40g).
Ratiometric
The variation of the accelerometer’s output offset and sensitivity linearly proportional to
the variation of the power supply voltage.
Sensitivity
The change in output voltage per unit g of acceleration applied. This is specified in mV/g.
Sensitive Axis
The most sensitive axis of the accelerometer. On the DIP package, acceleration is in the
direction perpendicular to the top of the package (positive acceleration going into the
device). On the SIP package, acceleration is in the direction perpendicular to the pins.
Transverse Acceleration
Any acceleration applied 90° to the axis of sensitivity.
Transverse Sensitivity Error
The percentage of a transverse acceleration that appears at the output. For example, if
the transverse sensitivity is 1%, then a +40 g transverse acceleration will cause a 0.4 g
signal to appear on the output. Transverse sensitivity can result from sensitivity of the
g–cell to transverse forces.
Motorola Sensor Device Data
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2–110
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Section Three
Pressure
Sensor Products
Mini Selector Guide . . . . . . . . . . . . . . . . . . . . . . . . . 3–2
General Information:
Device Numbering System . . . . . . . . . . . . . . . . . . 3–4
Package Offerings . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–5
Pressure Sensor Overview
Motorola’s pressure sensors are silicon micromachined, electromechanical devices featuring device uniformity and consistency, high reliability, accuracy and repeatability at
competitively low costs. With more than 20 years in pressure
sensor engineering, technology development and manufacturing, these pressure sensors have been designed into automotive, industrial, healthcare, commercial and consumer
products worldwide.
Pressure sensors operate in pressures up to 150psi (1000
kPa). For maximum versatility, Motorola pressure sensors are
single silicon, piezoresistive devices with three levels of device sophistication. The basic sensor device provides uncompensated sensing, the next level adds device compensation
and the third and most value added pressure sensors are the
integrated devices. Compensated sensors are available in
temperature compensated and calibrated configurations; integrated devices are available in temperature compensated,
calibrated and signal conditioned (or amplified) configurations. Each sensor family is available in gauge, absolute and
differential pressure references in a variety of packaging and
porting options.
Motorola Sensor Device Data
Orderable Part Numbers . . . . . . . . . . . . . . . . . . . . . 3–6
Pressure Sensor Overview
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–7
Motorola Pressure Sensors . . . . . . . . . . . . . . . . . . . . 3–8
Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–12
Sensor Applications . . . . . . . . . . . . . . . . . . . . . . . . . 3–13
Pressure Sensor FAQ’s . . . . . . . . . . . . . . . . . . . . . . 3–14
Data Sheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–15
Application Notes . . . . . . . . . . . . . . . . . . . . . . . . . 3–188
Case Outlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–423
Reference Information
Reference Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–439
Mounting and Handling Suggestions . . . . . . . . . . 3–441
Standard Warranty Clause . . . . . . . . . . . . . . . . . . . 3–442
Glossary of Terms . . . . . . . . . . . . . . . . . . . . . . . . . 3–443
Symbols, Terms and Definitions . . . . . . . . . . . 3–446
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Freescale Semiconductor, Inc.
Mini Selector Guide
PRESSURE SENSORS
Uncompensated Pressure Sensors
Product
Family
Pressure
Rating
Maximum
(psi)
Pressure
Rating
Maximum
(kPa)
Pressure
Rating
Maximum
(in H2O)
Pressure
Rating
Maximum
(cm H20)
Pressure
Rating
Maximum
(mm Hg)
Offset
(Typ)
(mV)
Full Scale
Span
(Typ)
(mV)
Sensitivity
(mV/kPa)
MPX10
1.45
10
40
102
75
20
35
3.5
MPX12
1.45
10
40
102
75
20
55
3.5
MPX53
7
50
200
510
375
20
60
Pressure
Rating
Maximum
(in H2O)
Pressure
Rating
Maximum
(cm H20)
Pressure
Rating
Maximum
(mm Hg)
Offset
(mV)
Pressure
Type Note
A
D
G
1.2
D
D
D
D
D
D
Full Scale
Span
(Typ)
(mV)
Sensitivity
(mV/kPa)
Pressure
Type Note
Note: A = Absolute, D = Differential, G = Gauge, V = Vacuum
Freescale Semiconductor, Inc...
Compensated Pressure Sensors
Product
Family
Pressure
Rating
Maximum
(psi)
Pressure
Rating
Maximum
(kPa)
MPX2010
1.45
10
40
102
75
±1.0
25
2.5
MPX2053
7
50
201
510
375
±1.0
40
0.8
MPX2102
14.5
14.5
100
100
400
400
1020
750
750
±2.0
±1.0
40
40
0.4
0.4
D
MPX2202
29
29
200
200
800
800
2040
1500
1500
±1.0
±1.0
40
40
0.2
0.2
D
MPX2050
7
50
201
510
375
±1.0
40
0.8
MPX2100
14.5
14.5
100
100
400
400
1020
750
750
±2.0
±1.0
40
40
0.4
0.4
D
29
29
200
200
800
800
2040
1500
1500
±1.0
±1.0
40
40
0.2
0.2
D
MPX2200
A
D
G
D
D
V
D
V
D
V
D
D
D
V
D
V
D
Note: A = Absolute, D = Differential, G = Gauge, V = Vacuum
Compensated Medical Grade Pressure Sensors
Product
Family
Pressure
Rating
Maximum
(psi)
Pressure
Rating
Maximum
(kPa)
Pressure
Rating
Maximum
(in H2O)
Pressure
Rating
Maximum
(cm H20)
Pressure
Rating
Maximum
(mm Hg)
Supply
Voltage
(Typ)
(Vdc)
Offset
Maximum
(mV)
Sensitivity
(mV/kPa)
MPXC2011
1.45
10
40
102
75
10.0
1.0
n/a
MPX2300
5.8
40
161
408
300
6.0
0.75
5.0
Pressure
Type Note
A
D
G
D
D
Note: A = Absolute, D = Differential, G = Gauge, V = Vacuum
3–2
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
PRESSURE SENSORS (continued)
Integrated Pressure Sensors
Freescale Semiconductor, Inc...
Product
Family
Pressure
Rating
Maximum
(psi)
Pressure
Rating
Maximum
(kPa)
Pressure
Rating
Maximum
(in H2O)
Pressure
Rating
Maximum
(cm H2O)
Pressure
Rating
Maximum
(mm Hg)
Full
Scale
Span
(Typ)
(Vdc)
Sensitivity
(mV/kPa)
Accuracy
0_C–85_C
(% of
VFSS)
MPX4080
11.6
80
321
815
600
4.3
54
±3.0
MPX4100
15.2
105
422
1070
788
4.6
54
±1.8
MPX4101
14.8
102
410
1040
765
4.6
54
±1.8
MPXH6101
14.8
102
410
1040
765
4.6
54
±1.8
MPX4105
15.2
105
422
1070
788
4.6
51
±1.8
MPX4115
16.7
115
462
1174
863
4.6
46
±1.5
16.7
115
462
1174
863
4
38
±1.5
MPX6115
16.7
115
462
1174
863
4.6
46
±1.5
MPX4200
29
200
803
2040
1500
4.6
26
±1.5
MPX4250
36
250
1000
2550
1880
4.7
20
±1.5
36
250
1000
2550
1880
4.7
19
±1.4
MPXV4006
0.87
6
24
61
45
4.6
766
±5.0
MPXV5004
0.57
4
16
40
29
3.9
1000
±2.5
MPX5010
1.45
10
40
102
75
4.5
450
±5.0
MPX5050
7.25
50
201
510
375
4.5
90
±2.5
MPX5100
14.5
100
401
1020
750
4.5
45
±2.5
16.7
115
462
1174
863
4.5
45
±2.5
MPX5500
72.5
500
2000
5100
3750
4.5
9
±2.5
MPX5700
102
700
2810
7140
5250
4.5
6
±2.5
MPX5999
150
1000
4150
10546
7757
4.5
5
±2.5
MPXH6300
44
300
1200
3060
2250
4.7
16
±1.8
Pressure
Type Note
A
D
G
D
D
D
D
D
D
V
D
D
D
D
D
D
D
D
D
D
V
V
V
D
D
D
D
D
D
D
D
D
D
Note: A = Absolute, D = Differential, G = Gauge, V = Vacuum
Motorola Sensor Device Data
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3–3
Freescale Semiconductor, Inc.
Device Numbering System for Pressure Sensors
M PX A 2 XXX A P X T1
PRESSURE SENSORS
LEADFORM OPTIONS
PACKAGE TYPE
CATEGORY
M Qualified standard
S Custom device
P,X Prototype device
None
A/V
AZ
Unibody
Small outline package (SOP)
Small outline media
resistant package
Chip pak
Super small outline
package (SSOP)
M–Pak
Super small outline
package (TPMP)
C
H
Freescale Semiconductor, Inc...
M
Y
NONE
No leadform
0
Open
1 thru 2
(Consult factory)
3 thru 5
Open
6 thru 7
SOP only
(6 = Gull wing/Surface mount)
(7 = 87 degrees/DIP)
FEATURES*
SHIPPING METHOD
None Trays
T1
Tape and reel
1 indicates
part orientation
in tape
U
Rail
PORTING STYLE
None Uncompensated
2
Temperature compensated/
calibrated
3
Open
4
Temperature compensated/
calibrated/signal conditioned
Automotive accuracy
5
Temperature compensated/
calibrated/signal conditioned
6
High temperature
7
Open
8
CMOS
Rated pressure in kPa,
except for MPX2300,
expressed in mmHg.
C
P
Axial port (small outline package)
Ported
Single port (AP, GP, GVP)
Dual port (DP)
S
Stovepipe port (unibody)
SX Axial port (unibody)
TYPE OF DEVICE
A
G
D
V
Absolute
Gauge
Differential
Vacuum/Gauge
Note: Actual product marking may be abbreviated due to space constraints but packaging label will reflect full part number.
*Only applies to qualified and prototype devices. This does not apply to custom devices.
Examples:
MPX10DP
10 kPa uncompensated, differential device in minibody package, ported, no leadform, shipped in trays.
MPXA4115A6T1
115 kPa automotive temperature compensated and calibrated device with signal conditioning, SOP surface mount with
gull wing leadform, shipped in tape and reel.
3–4
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
What Are the Pressure Packaging Options?
Freescale Semiconductor, Inc...
Pressure Sensor Packaging
(Sizes not to scale)
UNIBODY
BASIC ELEMENT
CASE 344
SUFFIX A / D
UNIBODY
SINGLE PORT
CASE 344B
SUFFIX AP / GP
UNIBODY
DUAL PORT
CASE 344C
SUFFIX DP
MEDICAL
CHIP PAK
CASE 423A
SUFFIX DT1
UNIBODY
STOVEPIPE PORT
CASE 344E
SUFFIX AS / GS
UNIBODY
BASIC ELEMENT
CASE 867
SUFFIX A / D
UNIBODY
SINGLE PORT
CASE 867B
SUFFIX AP / GP
UNIBODY
DUAL PORT
CASE 867C
SUFFIX DP
UNIBODY
AXIAL PORT
CASE 867F
SUFFIX ASX / GSX
UNIBODY
STOVEPIPE PORT
CASE 867E
SUFFIX AS / GS
Preferred Pressure Sensor Packaging Options
J
SOP
CASE 482
SUFFIX AG / G6
SOP AXIAL PORT
CASE 482A
SUFFIX AC6 / GC6
SOP SIDE PORT
CASE 1369
SUFFIX AP / GP
Motorola Sensor Device Data
SOP
CASE 482B
SUFFIX G7U
SOP DUAL PORT
CASE 1351
SUFFIX DP
SOP AXIAL PORT
CASE 482C
SUFFIX GC7U
SOP VACUUM PORT
CASE 1368
SUFFIX GVP
MPAK
CASE 1320
SUFFIX A / D
SSOP
CASE 1317
SUFFIX A6
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Information On This Product,
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MPAK AXIAL PORT
CASE 1320A
SUFFIX AS / GS
SSOP AXIAL PORT
CASE 1317A
SUFFIX AC6
3–5
Freescale Semiconductor, Inc.
Orderable Part Numbers
PRESSURE SENSOR ORDERABLE PART NUMBERS
Uncompensated
Freescale Semiconductor, Inc...
MPX4100A
MPX4250A
MPX10D
MPX2102GP
MPXV5004GC6T1
MPX4100AP
MPX4250AP
MPX10DP
MPX2102DP
MPXV5004GC6U
MPX4100AS
MPXA4250AC6T1
MPX10GP
MPX2102GSX
MPXV5004GC7U
MPXA4100AC6U
MPXA4250AC6U
MPX10GS
MPX2102GVP
MPXV5004G6T1
MPXA4100A6T1
MPXA4250A6T1
MPXV10GC6T1
MPXM2102D
MPXV5004G6U
MPXA4100A6U
MPXA4250A6U
MPXV10GC6U
MPXM2102DT1
MPXV5004G7U
MPXAZ4100AC6T1
MPXH6300ACGU
MPXV10GC7U
MPXM2102GS
MPXV5004GP
MPXAZ4100AC6U
MPXH6300AC6T1
MPX12D
MPXM2102GST1
MPXV5004DP
MPXAZ4100A6T1
MPXH6300A6U
MPX12DP
MPXV2102GP
MPXV5004GVP
MPXAZ4100A6U
MPXH6300A6T1
MPX12GP
MPXV2102DP
MPXV4006GC6T1
MPX4101A
MPX5700D
MPX53D
MPX2102A
MPXV4006GC6U
MPXA4101AC6U
MPX5700DP
MPX53DP
MPX2102AP
MPXV4006GC7U
MPXH6101A6T1
MPX5700GP
MPX53GP
MPX2102ASX
MPXV4006G6T1
MPXH6101A6U
MPX5700GS
MPXV53GC6T1
MPXM2102A
MPXV4006G6U
MPX4105A
MPXV6115VC6U
MPXV53GC6U
MPXM2102AT1
MPXV4006G7U
MPXV4115VC6U
MPXAZ6115A6U
MPXV53GC7U
MPXM2102AS
MPXV4006GP
MPXV4115V6T1
MPXAZ6115A6T1
MPXM2102AST1
MPXV4006DP
MPXV4115V6U
MPXAZ6115AC6U
MPX2300DT1
MPX2100D
MPX5010D
MPX5700A
MPXAZ6115AC6T1
MPX2301DT1
MPX2100GP
MPX5010DP
MPX5700AP
MPX2010D
MPX2100DP
MPX5010DP1
MPX5700AS
MPX2010GP
MPX2100GSX
MPX5010GP
MPX5999D
MPX2010DP
MPX2100GVP
MPX5010GS
MPX4115A
MPX2010GS
MPX2100A
MPX5010GSX
MPX4115AP
MPX2010GSX
MPX2100AP
MPXV5010GC6T1
MPX4115AS
MPXM2010D
MPX2100ASX
MPXV5010GC6U
MPXA4115AC6T1
MPXM2010DT1
MPX2202D
MPXV5010GC7U
MPXA4115AC6U
MPXM2010GS
MPX2202GP
MPXV5010G6U
MPXA4115A6T1
MPXM2010GST1
MPX2202DP
MPXV5010G7U
MPXA4115A6U
MPXC2011DT1
MPX2202GSX
MPXV5010GP
MPXA4115AP
MPXC2012DT1
MPX2202GVP
MPXV5010DP
MPXAZ4115AC6T1
MPXV2010GP
MPXM2202D
MPX5500D
MPXAZ4115AC6U
MPXV2010DP
MPXM2202DT1
MPX5500DP
MPXAZ4115A6T1
MPX2053D
MPXM2202GS
MPX5050D
MPXAZ4115A6U
MPX2053GP
MPXM2202GST1
MPX5050DP
MPXA6115AC6T1
MPX2053DP
MPXV2202GP
MPX5050GP1
MPXA6115AC6U
MPX2053GSX
MPXV2202DP
MPX5050GP
MPXA6115A6T1
MPX2053GVP
MPX2202A
MPXV5050GP
MPXA6115A6U
MPXM2053D
MPX2202AP
MPXV5050DP
MPXH6115A6T1
MPXM2053DT1
MPX2202ASX
MPX5100D
MPXH6115A6U
MPXM2053GS
MPXM2202A
MPX5100DP
MPXH6115AC6T1
MPXM2053GST1
MPXM2202AT1
MPX5100GP
MPXH6115AC6U
MPXV2053GP
MPXM2202AS
MPX5100GSX
MPX4200A
MPXV2053DP
MPXM2202AST1
MPX5100A
MPX4250D
MPX2050D
MPX2200D
MPX5100AP
MPX4250DP
MPX2050GP
MPX2200GP
MPX4080D
MPX4250GP
MPX2050DP
MPX2200DP
MPX2050GSX
MPX2200GSX
Compensated
MPX2102D
Integrated
MPX2200GVP
MPX2200A
MPX2200AP
3–6
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
General Product Information
PRESSURE SENSOR
APPLICATIONS VERSATILITY
For Motorola’s pressure sensors, new applications
emerge every day as engineers and designers realize that
they can convert their expensive mechanical pressure
sensors to Motorola’s lower–cost, semiconductor–based
devices. Applications include automotive and aviation,
industrial, healthcare and medical products and systems.
Choice of Packaging:
Available as a basic element for custom mounting, or in
conjunction with Motorola’s designed ports, printed circuit
board mounting is easy. Our Small Outline and Super Small
Outline packaging options provide surface mount, low
profile, and top piston fit package selections. Alternate
packaging material, which has been designed to meet
biocompatibility requirements, is also available.
70
VS = 3.0 Vdc
P1 > P2
60
+25°C
+125°C
40
30
OFFSET
(TYP)
20
10
PSI
kPa
0
0
2.0
10
20
4.0
30
ACCURACY
6.0 8.0
10
40 50 60 70
12
14
16
80 90 100
PRESSURE DIFFERENTIAL
Computer controlled laser trimming of on-chip calibration
and compensation resistors provide the most accurate
pressure measurement over a wide temperature range.
Temperature effect on span is typically ± 0.5% of full scale
over a temperature range from 0 to 85°C, while the effect on
offset voltage over a similar temperature range is a maximum
of only ±1 mV.
UNLIMITED VERSATILITY
Choice of Specifications:
Motorola’s pressure sensors are available in pressure
ranges to fit a wide variety of automotive, healthcare,
consumer and industrial applications.
Choice of Measurement:
Devices are available for differential, absolute, or gauge
pressure measurements.
Choice of Chip Complexity:
Motorola’s pressure sensors are available as the basic
sensing element, with temperature compensation and calibration, or with full signal conditioning circuitry included on
the chip. Uncompensated devices permit external compensation to any degree desired.
Motorola Sensor Device Data
– 40°C
50
OUTPUT (mVdc)
The performance of Motorola pressure sensors is based
on its patented strain gauge design. Unlike the more
conventional pressure sensors which utilize four closely
matched resistors in a distributed Wheatstone bridge configuration, the device uses only a single piezoresistive element
ion implanted on an etched silicon diaphragm to sense the
stress induced on the diaphragm by an external pressure.
The extremely linear output is an analog voltage that is
proportional to pressure input and ratiometric with supply
voltage. High sensitivity and excellent long-term repeatability
make these sensors suitable for the most demanding
applications.
Figure 1. Typical Output versus Pressure
Differential
SPAN ERROR (% FULL SCALE) OFFSET ERROR (mV)
Freescale Semiconductor, Inc...
PERFORMANCE
SPAN RANGE (TYP)
Performance, competitive price and application versatility
are just a few of the Motorola pressure sensor advantages.
ERROR BAND LIMIT
2
1.5
1
0.5
SPAN ERROR
0
OFFSET ERROR
– 0.5
–1
– 1.5
–2
ERROR BAND LIMIT
– 50
– 25
0
25
50
75
100
125
150
TEMPERATURE (°C)
Curves of span and offset errors indicate the accuracy resulting from
on-chip compensation and laser trimming.
Figure 2. Temperature Error Band Limit and
Typical Span and Offset Errors
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Freescale Semiconductor, Inc.
Motorola Pressure Sensors
INTRODUCTION
Freescale Semiconductor, Inc...
Motorola pressure sensors combine advanced piezoresistive sensor architecture with integrated circuit technology to offer a
wide range of pressure sensing devices for automotive, medical, consumer and industrial applications. Selection versatility
includes choice of:
Pressure Ranges in PSI
Application Measurements
0 to 1.45, 0 to 6, 0 to 7.3, 0 to 14.5, 0 to 29, 0 to 75, 0 to 100,
Absolute, Differential, Gauge
0 to 150 psi.
Sensing Options
Package Options
Uncompensated, Temperature Compensated/Calibrated,
and Signal Conditioned (with on–chip amplifiers)
• Basic Element, Ported Elements for specific measurements
• Surface Mount and Through Hole, Low Profile packages
THE BASIC STRUCTURE
MOTOROLA’S LOCALIZED SENSING ELEMENTS
The Motorola pressure sensor is designed utilizing a
monolithic silicon piezoresistor, which generates a changing
output voltage with variations in applied pressure. The
resistive element, which constitutes a strain gauge, is ion
implanted on a thin silicon diaphragm.
Applying pressure to the diaphragm results in a resistance
change in the strain gauge, which in turn causes a change in
the output voltage in direct proportion to the applied
pressure. The strain gauge is an integral part of the silicon
diaphragm, hence there are no temperature effects due to
differences in thermal expansion of the strain gauge and the
diaphragm. The output parameters of the strain gauge itself
are temperature dependent, however, requiring that the
device be compensated if used over an extensive temperature range. Simple resistor networks can be used for narrow
temperature ranges, i.e., 0°C to 85°C. For temperature
ranges from – 40°C to +125°C, more extensive compensation networks are necessary.
Excitation current is passed longitudinally through the
resistor (taps 1 and 3), and the pressure that stresses the
diaphragm is applied at a right angle to the current flow. The
stress establishes a transverse electric field in the resistor
that is sensed as voltage at taps 2 and 4, which are located
at the midpoint of the resistor (Figure 3a).
The transducer (Figure 3) uses a single element eliminating the need to closely match the four stress and temperature sensitive resistors that form a distributed Wheatstone
bridge design. At the same time, it greatly simplifies the
additional circuitry necessary to accomplish calibration and
temperature compensation. The offset does not depend on
matched resistors but instead on how well the transverse
voltage taps are aligned. This alignment is accomplished in
a single photolithographic step, making it easy to control,
and is only a positive voltage, simplifying schemes to zero
the offset.
ËËËË
ËËËË
ËËËË
ËËË
ËËËË
ËËË
ËËË
ËË
Ë
ËË
S–
ACTIVE
ELEMENT
ETCHED
DIAPHRAGM
BOUNDARY
S+
VOLTAGE
TAPS
TRANSVERSE
VOLTAGE STRAIN
GAUGE RESISTOR
1
4
2 3
PIN #
1. GROUND
2. +VOUT
3. VS
4. –VOUT
Figure 3. X–ducer Sensor Element — Top View
3–8
S–
ETCHED
DIAPHRAGM
BOUNDARY
S+
ACTIVE ELEMENT
HAS FOUR
P– RESISTORS
TRANSVERSE
VOLTAGE STRAIN
GAUGE RESISTOR
1
4
2 3
PIN #
1. GROUND
2. +VOUT
3. VS
4. –VOUT
Figure 3a. Localized Sensing Element
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
LINEARITY
LEAST SQUARES FIT
EXAGGERATED
PERFORMANCE
CURVE
RELATIVE VOLTAGE OUTPUT
Linearity refers to how well a transducer’s output follows
the equation: Vout = Voff + sensitivity x P over the operating
pressure range. There are two basic methods for calculating
nonlinearity: (1) end point straight line fit (see Figure 4) or
(2) a least squares best line fit. While a least squares fit gives
the “best case” linearity error (lower numerical value), the
calculations required are burdensome.
Conversely, an end point fit will give the “worst case” error
(often more desirable in error budget calculations) and the
calculations are more straightforward for the user. Motorola’s
specified pressure sensor linearities are based on the end
point straight line method measured at the midrange pressure.
STRAIGHT
LINE
DEVIATION
LEAST SQUARE
DEVIATION
END POINT
STRAIGHT LINE FIT
OFFSET
Freescale Semiconductor, Inc...
0
50
100
PRESSURE (% FULLSCALE)
Figure 4. Linearity Specification Comparison
NEGATIVE PRESSURE
VACUUM
OPERATION
ÉÉÉÉ
Motorola pressure sensors provide three types
of pressure measurement: Absolute Pressure,
Differential Pressure and Gauge Pressure.
Absolute Pressure Sensors measure an
external pressure relative to a zero–pressure
reference (vacuum) sealed inside the reference
chamber of the die during manufacture. This
corresponds to a deflection of the diaphragm
equal to approximately 14.5 psi (one atmosphere), generating a quiescent full–scale output
for the MPXH6101A6T1 (14.5 psi) sensor, and a
half–scale output for the MPX4200A (29 psi)
device. Measurement of external pressure is
accomplished by applying a relative negative
pressure to the “Pressure” side of the sensor.
Differential Pressure Sensors measure the
difference between pressures applied simultaneously to opposite sides of the diaphragm. A
positive pressure applied to the “Pressure” side
generates the same (positive) output as an equal
negative pressure applied to the “Vacuum” side.
Motorola Sensor Device Data
POSITIVE PRESSURE
NEGATIVE
PRESSURE
Absolute
Sensor
Differential
Sensor
VOFF
VOFF
1 ATM PMAX
INCREASING VACUUM
INCREASING PRESSURE
PMAX
DIFFERENTIAL PRESSURE
INCREASING
Motorola sensing elements can withstand pressure inputs as high as four times their rated
capacity, although accuracy at pressures exceeding the rated pressure will be reduced.
When excessive pressure is reduced, the previous linearity is immediately restored.
Figure 5. Pressure Measurements
Gauge Pressure readings are a special case of differential measurements in which the pressure applied to the “Pressure” side is measured
against the ambient atmospheric pressure applied to the “Vacuum” side
through the vent hole in the chip of the differential pressure sensor
elements.
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Freescale Semiconductor, Inc.
Typical Electrical Characteristic Curves
100
35
OUTPUT (mVdc)
30
25
90
80
TYP
MAX
20
15
10
MIN
5
0
kPa
PSI
–5
0
25
3.62
50
7.25
75
10.87
100
14.5
60
50
40
OUTPUT (Volts)
– 40°C
10
00
OFFSET
(TYP)
PSI
0
kPa
+ 125°C
UNCOMPENSATED
30
20
COMPENSATED
1
2
10
TA = – 40 TO + 125°C
3
4
5
6
20
30
40
PRESSURE DIFFERENTIAL
7
8
50
Figure 7. Typical–Output Voltage versus
Pressure and Temperature for Compensated
and Uncompensated Devices
Figure 6. Output versus Pressure Differential
Freescale Semiconductor, Inc...
COMPENSATED VS = 10 Vdc
UNCOMPENSATED VS = 3 Vdc
P1 > P2
+ 25°C
70
SPAN
RANGE
(TYP)
OUTPUT (mVdc)
VS = 10 Vdc
TA = 25°C
MPX2100
P1 > P2
40
5.0
MAX
TRANSFER FUNCTION:
4.5
Vout = Vs* (0.009*P – 0.04) ± error
4.0 Vs = 5.0 Vdc
3.5 TEMP = 0 to 85°C
3.0 MPX5100D
P1 > P2
2.5
TYP
2.0
1.5
1.0
MIN
0.5
0
0
10
20
30
40
50
60
70
80 90 100 110
DIFFERENTIAL PRESSURE (in kPa)
Figure 8. Signal Conditioned MPX5100
3–10
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
Unibody Cross–sectional Drawings
SILICONE GEL
DIE COAT
WIRE BOND
DIFFERENTIAL/GAUGE
STAINLESS STEEL
DIE
METAL COVER
P1
EPOXY
CASE
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
LEAD FRAME
DIFFERENTIAL/GAUGE ELEMENT
P2
DIE
BOND
SILICONE GEL ABSOLUTE
DIE COAT
DIE
P1
STAINLESS STEEL
METAL COVER
EPOXY
CASE
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
WIRE BOND
LEAD FRAME
ABSOLUTE ELEMENT
DIE
BOND
Freescale Semiconductor, Inc...
Figure 9. Cross–Sectional Diagrams (not to scale)
Figure 9 illustrates the absolute sensing configuration
(right) and the differential or gauge configuration in the basic
chip carrier (Case 344). A silicone gel isolates the die surface
and wire bonds from harsh environments, while allowing the
pressure signal to be transmitted to the silicon diaphragm.
The MPX series pressure sensor operating characteristics
and internal reliability and qualification tests are based on use
of dry air as the pressure media. Media other than dry air may
have adverse effects on sensor performance and long term
stability. Contact the factory for information regarding media
compatibility in your application.
STAINLESS STEEL
METAL COVER
DIE
FLUORO SILICONE
DIE COAT
P1
WIRE BONDS
EPOXY CASE
LEAD FRAME
Figure 10. Cross–Sectional Diagram (not to scale)
Figure 10 illustrates the differential/gauge die in the
basic chip carrier (Case 473). A silicone gel isolates the
die surface and wirebonds from the environment, while
Motorola Sensor Device Data
allowing the pressure signal to be transmitted to the
silicon diaphragm.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–11
Freescale Semiconductor, Inc.
Integration
+5 V
ON-CHIP SIGNAL CONDITIONING
Freescale Semiconductor, Inc...
To make the designer’s job even easier, Motorola’s
integrated devices carry sensor technology one step further.
In addition to the on-chip temperature compensation and
calibration offered currently on the 2000 series, amplifier
signal conditioning has been integrated on-chip in the 4000,
5000 and 6000 series to allow interface directly to any
microcomputer with an on-board A/D converter.
The signal conditioning is accomplished by means of a
four-stage amplification network, incorporating linear bipolar
processing, thin-film metallization techniques, and interactive laser trimming to provide the state-of-the-art in sensor
technology.
3
m
1.0 F
1
m
OUTPUT
470 pF
0.01 F
IPS
2
Recommended Power Supply Decoupling.
For output filtering recommendations, please refer
to Application Note AN1646.
Design Considerations for Different Levels of Sensor Integration
DESIGN ADVANTAGES
Uncompensated Sensors
DESIGN CONSIDERATIONS
High Sensitivity
Device–to–Device Variation in Offset
and Span
Lowest Device Cost
Temperature Compensation
Circuitry Required
Low–Level Output Allows Flexibility
of Signal Conditioning
Requires Signal Conditioning/
Amplification of Output Signal
Relatively Low Input Impedance
(400 Ω Typical)
Temperature Compensated &
Calibrated (2000 Series)
Reduced Device–to–Device
Variations in Offset and Span
Lower Sensitivity Due to Span
Compensation (Compared to
Uncompensated)
Reduced Temperature Drift in Offset
and Span
Priced Higher than Uncompensated
Device
Reasonable Input Impedance
(2K Ω Typical)
Requires Signal Conditioning/
Amplification of Output Signal
Low Level Output Allows Flexibility in
Signal Conditioning
Integrated Pressure Sensors
(4000, 5000 and 6000 Series)
No Amplification Needed
Direct Interface to MPU
Priced Higher than Compensated/
Uncompensated Device
Signal Conditioning, Calibration of
Span and Offset, Temperature
Compensation Included On–Chip
3–12
For www.motorola.com/semiconductors
More Information On This Product,
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
Sensor Applications
AUTOMOTIVE/AVIATION APPLICATIONS
INDUSTRIAL/COMMERCIAL APPLICATIONS
• Fuel Level Indicator
• Electronic Fire Fighting Control
• Altimeters
• Flow Control
• Air Speed Indicator
• Barometer
• Ejection Seat Control
• HVAC Systems
• Turbo Boost Control
• Tire Pressure Monitoring
• Manifold Vacuum Control
• Water Filtered Systems (Flow Rate Indicator)
• Fuel Flow Metering
• Air Filtered Systems (Flow Rate Indicator)
• Oil Filter Flow Indicator
• Tactile Sensing for Robotic Systems
• Oil Pressure Sensor
• Boiler Pressure Indicators
Freescale Semiconductor, Inc...
• Air Flow Measurement
• Anti–Start
• End of Tape Readers
• Breathalizer Systems
• Disc Drive Control/Protection Systems
• Smart Suspension Systems
• Ocean Wave Measurement
• Variometer–Hang glider & Sailplanes
• Diving Regulators
• Automotive Speed Control
• Oil Well Logging
HEALTHCARE APPLICATIONS
• Building Automation (Balancing, Load Control, Windows)
• Fluid Dispensers
• Blood Pressure
• Explosion Sensing — Shock Wave Monitors
• Esophagus Pressure
• Load Cells
• Heart Monitor
• Autoclave Release Control
• Interoccular Pressure
• Soil Compaction Monitor — Construction
• Saline Pumps
• Water Depth Finders (Industrial, Sport Fishing/Diving)
• Kidney Dialysis
• Pneumatic Controls — Robotics
• Blood Gas Analysis
• Pinch Roller Pressure — Paper Feed
• Blood Serum Analysis
• Blower Failure Safety Switch — Computer
• Seating Pressure (Paraplegic)
• Vacuum Cleaner Control
• Respiratory Control
• Intravenous Infusion Pump Control
• Electronic Drum
• Hospital Beds
• Pressure Controls Systems — Building, Domes
• Drug Delivery
• Engine Dynamometer
• IUPC
• Water Level Monitoring
• Patient Monitors
• Altimeters
Motorola has tested media tolerant sensor devices in selected solutions or environments and test results are based on particular conditions and
procedures selected by Motorola. Customers are advised that the results may vary for actual services conditions. Customers are cautioned that
they are responsible to determine the media compatibility of sensor devices in their applications and the foreseeable use and misuses of their
applications.
Motorola Sensor Device Data
www.motorola.com/semiconductors
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Information On This Product,
Go to: www.freescale.com
3–13
Freescale Semiconductor, Inc.
Pressure Sensor FAQ’s
We have discovered that many of our customers have
similar questions about certain aspects of our pressure
sensor technology and operation. Here are the most
frequently asked questions and answers that have been
explained in relatively non–technical terms.
Freescale Semiconductor, Inc...
Q. How do I calculate total pressure error for my
applications?
A. You can calculate total error in two fashions, worst case
error and most probable error. Worst case error is taking
all the individual errors and adding them up, while most
probable error sums the squares of the individual errors
and then take the square root of the total. In summary,
Error (Worst Case) = E1 + E2 + E3 + ... + En, while Error
(Most Probable) = SQRT[(E1)2 + (E2)2 + (E3)2 + ...
(En)2]; Please note that not all errors may apply in your
individual application.
Q. What is the media tolerance of our pressure sensors?
A. Most Motorola pressure sensors are specifically designed for dry air applications. However, Motorola now
offers an MPXAZ series specifically designed for improved media resistance. This series incorporates a
durable barrier that allows the sensor to operate reliably
in high humidity conditions as well as environments
containing common automotive media. NOTE: Applications exposing the sensor to media other than what has
been specified could potentially limit the lifetime of the
sensor. Please consult the Motorola factory for more
information regarding media compatibility in your specific
application.
Q. Can I pull a vacuum on P1?
A. Motorola pressure sensors are designed to measure
pressure in one direction and are not bi–directional. It is
3–14
possible to measure either a positive pressure OR a
negative pressure, but not both. For example, the sensor
can be designed to accept a ”positive” pressure on the
P1 port, providing that P1 is greater or equal to P2 while
staying with in the sensors specified pressure range. Or,
the sensor can measure ”negative” pressure (a vacuum)by applying the pressure to the P2 port, again while
P1 is greater or equal to P2 and staying within the
sensors specified range.
Our pressure sensors are based on a silicon diaphragm
and can not tolerate a pressure that alternates from
positive to negative without resulting damage. The
devices are rated for over pressure and burst but should
not be intentionally designed to operate in a bi–directional manner.
If you need to measure both a positive and negative
pressure within the same system, we suggest designing
with two separate sensors, one for each pressure type.
Or, a mechanical pressure transducer should be utilized.
Q. What will happen if I run the pressure sensor beyond
the rated operating pressure?
A. For bare elements (uncompensated and compensated
series devices), when you take the sensor higher than
the rated pressure, the part will still provide an output
increasing linearly with pressure. When you go below the
minimum rated pressure, the output of the sensor will
eventually go negative. Motorola, however, does not
guarantee electrical specifications beyond the rated
operating pressure range specified in the data sheet of
each device. The integrated series devices will not
function at all beyond the rated pressure of the part.
These series of parts will saturate at near 4.8 V and 0.2 V
and thus no further change in output will occur.
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
10 kPa Uncompensated
Silicon Pressure Sensors
The MPX10 and MPXV10GC series devices are silicon piezoresistive pressure sensors
providing a very accurate and linear voltage output — directly proportional to the applied
pressure. These standard, low cost, uncompensated sensors permit manufacturers to
design and add their own external temperature compensation and signal conditioning
networks. Compensation techniques are simplified because of the predictability of
Motorola’s single element strain gauge design. Figure 1 shows a schematic of the internal
circuitry on the stand–alone pressure sensor chip.
MPX10
MPXV10GC
SERIES
0 to 10 kPa (0 – 1.45 psi)
35 mV FULL SCALE SPAN
(TYPICAL)
Features
• Low Cost
SMALL OUTLINE PACKAGE
UNIBODY PACKAGE
Freescale Semiconductor, Inc...
• Patented Silicon Shear Stress Strain Gauge Design
• Ratiometric to Supply Voltage
• Easy to Use Chip Carrier Package Options
• Differential and Gauge Options
• Durable Epoxy Unibody Element or Thermoplastic
(PPS) Surface Mount Package
MPXV10GC6U
CASE 482A
Application Examples
MPX10D
CASE 344
• Air Movement Control
• Environmental Control Systems
• Level Indicators
• Leak Detection
• Medical Instrumentation
• Industrial Controls
• Pneumatic Control Systems
MPXV10GC7U
CASE 482C
• Robotics
3
PIN NUMBER
+ VS
2
+ Vout
SENSING
ELEMENT
4
– Vout
1
1
Gnd
5
N/C
2
+Vout
Vs
6
N/C
3
7
N/C
4
–Vout
8
N/C
NOTE: Pin 1 is noted by the notch in
the lead.
GND
MPX10DP
CASE 344C
PIN NUMBER
1
Gnd
3
VS
2
+Vout
4
–Vout
NOTE: Pin 1 is noted by the notch in
the lead.
Figure 1. Uncompensated Pressure
Sensor Schematic
VOLTAGE OUTPUT versus APPLIED DIFFERENTIAL PRESSURE
The output voltage of the differential or gauge sensor increases with increasing pressure
applied to the pressure side (P1) relative to the vacuum side (P2). Similarly, output voltage
increases as increasing vacuum is applied to the vacuum side (P2) relative to the pressure
side (P1).
REV 10
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–15
MPX10 MPXV10GC SERIESFreescale Semiconductor, Inc.
MAXIMUM RATINGS(NOTE)
Rating
Symbol
Value
Unit
Pmax
Pburst
Tstg
75
kPa
100
kPa
– 40 to +125
°C
Operating Temperature
TA
– 40 to +125
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
°C
Maximum Pressure (P1 > P2)
Burst Pressure (P1 > P2)
Storage Temperature
OPERATING CHARACTERISTICS (VS = 3.0 Vdc, TA = 25°C unless otherwise noted, P1 > P2)
Characteristic
Differential Pressure Range(1)
Supply Voltage(2)
Freescale Semiconductor, Inc...
Supply Current
Full Scale Span(3)
Offset(4)
Sensitivity
Linearity(5)
Symbol
Min
POP
VS
0
—
Typ
Max
Unit
—
10
kPa
3.0
6.0
Vdc
Io
VFSS
Voff
—
6.0
—
mAdc
20
35
50
mV
0
20
35
mV
∆V/∆P
—
3.5
—
mV/kPa
%VFSS
%VFSS
—
–1.0
—
1.0
Pressure Hysteresis(5) (0 to 10 kPa)
Temperature Hysteresis(5) (– 40°C to +125°C)
—
—
± 0.1
—
—
—
± 0.5
—
Temperature Coefficient of Full Scale Span(5)
Temperature Coefficient of Offset(5)
TCVFSS
TCVoff
– 0.22
—
– 0.16
—
±15
—
Temperature Coefficient of Resistance(5)
TCR
0.28
—
0.34
Input Impedance
Zin
Zout
400
—
550
750
—
1250
Ω
tR
—
—
1.0
—
ms
—
20
—
ms
—
—
± 0.5
—
%VFSS
Output Impedance
Response Time(6) (10% to 90%)
Warm–Up Time(7)
Offset Stability(8)
%VFSS
%VFSS/°C
µV/°C
%Zin/°C
Ω
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range. Operating the device above the specified excitation range may induce additional
error due to device self–heating.
3. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
4. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
5. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure, using end point method, over the specified
pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation at full rated pressure over the temperature range of 0 to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative
to 25°C.
• TCR:
Zin deviation with minimum rated pressure applied, over the temperature range of – 40°C to +125°C,
relative to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Warm–up Time is defined as the time required for the product to meet the specified output voltage after the pressure has been stabilized.
8. Offset Stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
3–16
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPX10 MPXV10GC SERIES
tion over both – 40 to +125°C and 0 to + 80°C ranges are
presented in Motorola Applications Note AN840.
TEMPERATURE COMPENSATION
Figure 2 shows the typical output characteristics of the
MPX10 and MPXV10GC series over temperature.
Because this strain gauge is an integral part of the silicon
diaphragm, there are no temperature effects due to differences in the thermal expansion of the strain gauge and the
diaphragm, as are often encountered in bonded strain gauge
pressure sensors. However, the properties of the strain
gauge itself are temperature dependent, requiring that the
device be temperature compensated if it is to be used over
an extensive temperature range.
Temperature compensation and offset calibration can be
achieved rather simply with additional resistive components,
or by designing your system using the MPX2010D series
sensor.
Several approaches to external temperature compensa-
LINEARITY
Linearity refers to how well a transducer’s output follows
the equation: Vout = Voff + sensitivity x P over the operating
pressure range (Figure 3). There are two basic methods for
calculating nonlinearity: (1) end point straight line fit or (2) a
least squares best line fit. While a least squares fit gives the
“best case” linearity error (lower numerical value), the calculations required are burdensome.
Conversely, an end point fit will give the “worst case” error
(often more desirable in error budget calculations) and the
calculations are more straightforward for the user. Motorola’s
specified pressure sensor linearities are based on the end
point straight line method measured at the midrange pressure.
70
70
60
– 40°C
50
SPAN
RANGE
(TYP)
+ 125°C
40
30
20
OFFSET
(TYP)
10
0
PSI 0
kPa
0.3
2.0
0.6
0.9
1.2
4.0
6.0
8.0
PRESSURE DIFFERENTIAL
1.5
50
ACTUAL
40
SPAN
(VFSS)
30
THEORETICAL
20
10
OFFSET
(VOFF)
MAX
POP
0
0
10
PRESSURE (kPA)
Figure 2. Output versus Pressure Differential
SILICONE
DIE COAT
Figure 3. Linearity Specification Comparison
STAINLESS STEEL
METAL COVER
EPOXY
CASE
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
DIE
P1
WIRE BOND
LINEARITY
60
+ 25°C
VS = 3 Vdc
P1 > P2
OUTPUT (mVdc)
OUTPUT (mVdc)
Freescale Semiconductor, Inc...
80
LEAD FRAME
P2
RTV DIE
BOND
Figure 4. Unibody Package — Cross–Sectional
Diagram (not to scale)
Figure 4 illustrates the differential or gauge configuration
in the basic chip carrier (Case 344). A silicone gel isolates
the die surface and wire bonds from the environment, while
allowing the pressure signal to be transmitted to the silicon
diaphragm.
The MPX10 and MPXV10GC series pressure sensor oper-
Motorola Sensor Device Data
ating characteristics and internal reliability and qualification
tests are based on use of dry air as the pressure media. Media other than dry air may have adverse effects on sensor performance and long term reliability. Contact the factory for
information regarding media compatibility in your application.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–17
MPX10 MPXV10GC SERIESFreescale Semiconductor, Inc.
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing silicone gel which
isolates the die from the environment. The Motorola pres-
Freescale Semiconductor, Inc...
Part Number
sure sensor is designed to operate with positive differential
pressure applied, P1 > P2.
The Pressure (P1) side may be identified by using the table
below:
Case Type
Pressure (P1) Side Identifier
MPX10D
344
Stainless Steel Cap
MPX10DP
344C
Side with Part Marking
MPX10GP
344B
Side with Port Attached
MPX10GS
344E
Side with Port Attached
MPXV10GC6U
482A
Side with Part Marking
MPXV10GC7U
482C
Side with Part Marking
ORDERING INFORMATION — UNIBODY PACKAGE
MPX10 series pressure sensors are available in differential and gauge configurations. Devices are available in the basic
element package or with pressure port fittings which provide printed circuit board mounting ease and barbed hose pressure
connections.
MPX Series
Device Type
Options
Case Type
Order Number
Device Marking
Basic Element
Differential
Case 344
MPX10D
MPX10D
Ported Elements
Differential
Case 344C
MPX10DP
MPX10DP
Gauge
Case 344B
MPX10GP
MPX10GP
Gauge
Case 344E
MPX10GS
MPX10D
ORDERING INFORMATION — SMALL OUTLINE PACKAGE (MPXV10GC SERIES)
No
Device Type/Order No.
Packing Options
Case Type
Device Marking
MPXV10GC6U
Rails
Case 482A
MPXV10G
MPXV10GC6T1
Tape and Reel
Case 482A
MPXV10G
MPXV10GC7U
Rails
Case 482C
MPXV10G
3–18
For www.motorola.com/semiconductors
More Information On This Product,
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Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
10 kPa Uncompensated
Silicon Pressure Sensors
The MPX12 series device is a silicon piezoresistive pressure sensor providing a very
accurate and linear voltage output — directly proportional to the applied pressure. This
standard, low cost, uncompensated sensor permits manufacturers to design and add
their own external temperature compensating and signal conditioning networks.
Compensation techniques are simplified because of the predictability of Motorola’s single
element strain gauge design.
Features
• Low Cost
MPX12
SERIES
0 to 10 kPa (0 – 1.45 psi)
55 mV FULL SCALE SPAN
(TYPICAL)
• Patented Silicon Shear Stress Strain Gauge Design
Freescale Semiconductor, Inc...
• Ratiometric to Supply Voltage
• Easy to Use Chip Carrier Package Options
• Differential and Gauge Options
• Durable Epoxy Package
Application Examples
• Air Movement Control
MPX12D
CASE 344
• Environmental Control Systems
• Level Indicators
• Leak Detection
• Medical Instrumentation
• Industrial Controls
• Pneumatic Control Systems
• Robotics
Figure 1 shows a schematic of the internal circuitry on the stand–alone pressure
sensor chip.
PIN 3
+ VS
MPX12DP
CASE 344C
PIN 2
+ Vout
SENSING
ELEMENT
PIN 4
– Vout
PIN 1
Figure 1. Uncompensated Pressure Sensor Schematic
PIN NUMBER
1
Gnd
3
VS
2
+Vout
4
–Vout
NOTE: Pin 1 is noted by the notch in
the lead.
VOLTAGE OUTPUT versus APPLIED DIFFERENTIAL PRESSURE
The output voltage of the differential or gauge sensor increases with increasing
pressure applied to the pressure side (P1) relative to the vacuum side (P2). Similarly,
output voltage increases as increasing vacuum is applied to the vacuum side (P2)
relative to the pressure side (P1).
REV 3
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–19
Freescale Semiconductor, Inc.
MPX12 SERIES
MAXIMUM RATINGS(NOTE)
Rating
Symbol
Value
Unit
Pmax
Pburst
Tstg
75
kPa
100
kPa
– 40 to +125
°C
Operating Temperature
TA
– 40 to +125
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
°C
Maximum Pressure (P1 > P2)
Burst Pressure (P1 > P2)
Storage Temperature
OPERATING CHARACTERISTICS (VS = 3.0 Vdc, TA = 25°C unless otherwise noted, P1 > P2)
Characteristic
Differential Pressure Range(1)
Supply Voltage(2)
Freescale Semiconductor, Inc...
Supply Current
Full Scale Span(3)
Offset(4)
Sensitivity
Linearity(5)
Symbol
Min
POP
VS
0
—
Typ
Max
Unit
—
10
kPa
3.0
6.0
Vdc
Io
VFSS
Voff
—
6.0
—
mAdc
45
55
70
mV
0
20
35
mV
∆V/∆P
—
5.5
—
mV/kPa
%VFSS
%VFSS
—
–0.5
—
5.0
Pressure Hysteresis(5) (0 to 10 kPa)
Temperature Hysteresis(5) (– 40°C to +125°C)
—
—
± 0.1
—
—
—
± 0.5
—
Temperature Coefficient of Full Scale Span(5)
Temperature Coefficient of Offset(5)
TCVFSS
TCVoff
– 0.22
—
– 0.16
%VFSS
%VFSS/°C
—
±15
—
µV/°C
Temperature Coefficient of Resistance(5)
TCR
0.28
—
0.34
Input Impedance
Zin
Zout
400
—
550
%Zin/°C
Ω
750
—
1250
Ω
tR
—
—
1.0
—
ms
—
20
—
ms
—
—
± 0.5
—
%VFSS
Output Impedance
Response Time(6) (10% to 90%)
Warm–Up Time(7)
Offset Stability(8)
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range. Operating the device above the specified excitation range may induce additional
error due to device self–heating.
3. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
4. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
5. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure, using end point method, over the specified
pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation at full rated pressure over the temperature range of 0 to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative
to 25°C.
• TCR:
Zin deviation with minimum rated pressure applied, over the temperature range of – 40°C to +125°C,
relative to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Warm–up Time is defined as the time required for the product to meet the specified output voltage after the pressure has been stabilized.
8. Offset Stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
3–20
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
tion over both – 40 to +125°C and 0 to + 80°C ranges are
presented in Motorola Applications Note AN840.
LINEARITY
Linearity refers to how well a transducer’s output follows
the equation: Vout = Voff + sensitivity x P over the operating
pressure range (Figure 3). There are two basic methods for
calculating nonlinearity: (1) end point straight line fit or (2) a
least squares best line fit. While a least squares fit gives the
“best case” linearity error (lower numerical value), the calculations required are burdensome.
Conversely, an end point fit will give the “worst case” error
(often more desirable in error budget calculations) and the
calculations are more straightforward for the user. Motorola’s specified pressure sensor linearities are based on the
end point straight line method measured at the midrange
pressure.
80
70
70
– 40°C
50
SPAN
RANGE
(TYP)
+ 125°C
40
30
20
OFFSET
(TYP)
10
0
PSI 0
kPa
0.3
2.0
0.6
0.9
1.2
4.0
6.0
8.0
PRESSURE DIFFERENTIAL
1.5
50
ACTUAL
40
SPAN
(VFSS)
30
THEORETICAL
20
10
OFFSET
(VOFF)
0
0
10
MAX
POP
PRESSURE (kPA)
Figure 2. Output versus Pressure Differential
SILICONE
DIE COAT
Figure 3. Linearity Specification Comparison
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
DIE
P1
WIRE BOND
LINEARITY
60
+ 25°C
VS = 3 Vdc
P1 > P2
OUTPUT (mVdc)
OUTPUT (mVdc)
Freescale Semiconductor, Inc...
TEMPERATURE COMPENSATION
Figure 2 shows the typical output characteristics of the
MPX12 series over temperature.
Because this strain gauge is an integral part of the silicon
diaphragm, there are no temperature effects due to differences in the thermal expansion of the strain gauge and the
diaphragm, as are often encountered in bonded strain gauge
pressure sensors. However, the properties of the strain
gauge itself are temperature dependent, requiring that the
device be temperature compensated if it is to be used over
an extensive temperature range.
Temperature compensation and offset calibration can be
achieved rather simply with additional resistive components,
or by designing your system using the MPX2010D series
sensor.
Several approaches to external temperature compensa-
60
MPX12 SERIES
LEAD FRAME
P2
STAINLESS STEEL
METAL COVER
EPOXY
CASE
RTV DIE
BOND
Figure 4. Cross–Sectional Diagram (not to scale)
Figure 4 illustrates the differential or gauge configuration
in the basic chip carrier (Case 344). A silicone gel isolates
the die surface and wire bonds from the environment, while
allowing the pressure signal to be transmitted to the silicon
diaphragm.
The MPX12 series pressure sensor operating characteris-
Motorola Sensor Device Data
tics and internal reliability and qualification tests are based
on use of dry air as the pressure media. Media other than
dry air may have adverse effects on sensor performance and
long term reliability. Contact the factory for information regarding media compatibility in your application.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–21
Freescale Semiconductor, Inc.
MPX12 SERIES
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing silicone gel which
isolates the die from the environment. The Motorola MPX
Part Number
pressure sensor is designed to operate with positive differential pressure applied, P1 > P2.
The Pressure (P1) side may be identified by using the table
below:
Case Type
Pressure (P1) Side Identifier
MPX12D
344
Stainless Steel Cap
MPX12DP
344C
Side with Part Marking
MPX12GP
344B
Side with Port Attached
Freescale Semiconductor, Inc...
ORDERING INFORMATION
MPX12 series pressure sensors are available in differential and gauge configurations. Devices are available in the basic
element package or with pressure port fittings which provide printed circuit board mounting ease and barbed hose pressure
connections.
MPX Series
Device Type
Options
Case Type
Order Number
Device Marking
Basic Element
Differential
Case 344
MPX12D
MPX12D
Ported Elements
Differential
Case 344C
MPX12DP
MPX12DP
Gauge
Case 344B
MPX12GP
MPX12GP
3–22
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
10 kPa On-Chip Temperature
Compensated & Calibrated
Silicon Pressure Sensors
UNIBODY PACKAGE
Freescale Semiconductor, Inc...
The MPX2010/MPXV2010G series silicon
piezoresistive pressure sensors provide a very
ac c ur at e and l i n e a r v o l ta g e o u tp u t — d i r ec tl y
proportional to the applied pressure. These sensors
house a single monolithic silicon die with the strain
gauge and thin–film resistor network integrated on
each chip. The sensor is laser trimmed for precise
span, offset calibration and temperature
compensation.
MPX2010
MPXV2010G
SERIES
Motorola Preferred Device
COMPENSATED
PRESSURE SENSOR
0 to 10 kPa (0 to 1.45 psi)
FULL SCALE SPAN: 25 mV
MPX2010D
CASE 344
Features
SMALL OUTLINE PACKAGE
SURFACE MOUNT
• Temperature Compensated over 0°C to + 85°C
• Ratiometric to Supply Voltage
• Differential and Gauge Options
Application Examples
• Respiratory Diagnostics
• Air Movement Control
MPX2010GP
CASE 344B
• Controllers
MPXV2010GP
CASE 1369
• Pressure Switching
Figure 1 shows a block diagram of the internal
circuitry on the stand–alone pressure sensor chip.
VS
3
THIN FILM
TEMPERATURE
COMPENSATION
AND
CALIBRATION
CIRCUITRY
SENSING
ELEMENT
2
4
MPX2010DP
CASE 344C
Vout+
MPXV2010DP
CASE 1351
Vout–
PIN NUMBER
1
GND
MPX2010GS
CASE 344E
Figure 1. Temperature Compensated and Calibrated
Pressure Sensor Schematic
1
Gnd
5
N/C
2
6
N/C
3
+Vout
VS
7
N/C
4
–Vout
8
N/C
NOTE: Pin 1 is noted by the notch in
the lead.
VOLTAGE OUTPUT versus
APPLIED DIFFERENTIAL PRESSURE
The output voltage of the differential or gauge sensor
increases with increasing pressure applied to the
pressure side (P1) relative to the vacuum side (P2).
Similarly, output voltage increases as increasing vacuum is applied to the vacuum side (P2) relative to the
pressure side (P1).
MPX2010GSX
CASE 344F
PIN NUMBER
Preferred devices are Motorola recommended choices for future use and
best overall value.
REV 9
Motorola Sensor Device Data
1
Gnd
3
VS
2
+Vout
4
–Vout
NOTE: Pin 1 is noted by the notch in
the lead.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–23
Freescale Semiconductor, Inc.
MPX2010 MPXV2010G SERIES
MAXIMUM RATINGS(NOTE)
Rating
Maximum Pressure (P1 > P2)
Storage Temperature
Operating Temperature
Symbol
Value
Unit
Pmax
75
kPa
Tstg
– 40 to +125
°C
TA
– 40 to +125
°C
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 10 Vdc, TA = 25°C unless otherwise noted, P1 > P2)
Characteristic
Symbol
Min
Typ
Max
Unit
Pressure Range(1)
POP
0
—
10
kPa
Supply Voltage(2)
VS
—
10
16
Vdc
Supply Current
Io
—
6.0
—
mAdc
VFSS
24
25
26
mV
Voff
–1.0
—
1.0
mV
Sensitivity
∆V/∆P
—
2.5
—
mV/kPa
Linearity(5)
—
–1.0
—
1.0
%VFSS
Pressure Hysteresis(5) (0 to 10 kPa)
—
—
± 0.1
—
%VFSS
Full Scale Span(3)
Freescale Semiconductor, Inc...
Offset(4)
Temperature Hysteresis(5) (– 40°C to +125°C)
Temperature Effect on Full Scale Span(5)
Temperature Effect on Offset(5)
Input Impedance
—
—
± 0.5
—
%VFSS
TCVFSS
–1.0
—
1.0
%VFSS
TCVoff
–1.0
—
1.0
mV
Zin
1000
—
2550
Ω
Zout
1400
—
3000
Ω
Response Time(6) (10% to 90%)
tR
—
1.0
—
ms
Warm–Up
—
—
20
—
ms
Offset Stability(7)
—
—
± 0.5
—
%VFSS
Output Impedance
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range. Operating the device above the specified excitation range may induce additional
error due to device self–heating.
3. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
4. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
5. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure, using end point method, over the specified
pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation at full rated pressure over the temperature range of 0 to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative
to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Offset stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
3–24
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, MPX2010
Inc.
MPXV2010G SERIES
ON–CHIP TEMPERATURE COMPENSATION and CALIBRATION
VS = 10 Vdc
TA = 25°C
P1 > P2
OUTPUT (mVdc)
30
25
20
aMAX
15
TYP
SPAN
RANGE
(TYP)
10
MIN
5
0
–5
kPa
PSI
2.5
0.362
5
0.725
7.5
1.09
10
1.45
OFFSET
(TYP)
Freescale Semiconductor, Inc...
Figure 2. Output versus Pressure Differential
This performance over temperature is achieved by having
both the shear stress strain gauge and the thin–film resistor
circuitry on the same silicon diaphragm. Each chip is dynamically laser trimmed for precise span and offset calibration
and temperature compensation.
Figure 2 shows the output characteristics of the
MPX2010/MPXV2010G series at 25°C. The output is directly proportional to the differential pressure and is essentially a
straight line.
The effects of temperature on full scale span and offset are
very small and are shown under Operating Characteristics.
SILICONE
DIE COAT
STAINLESS STEEL
METAL COVER
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
DIE
P1
EPOXY
CASE
WIRE BOND
LEAD FRAME
P2
RTV DIE
BOND
Figure 3. Unibody Package — Cross–Sectional
Diagram (not to scale)
Figure 3 illustrates the differential/gauge die in the basic
chip carrier (Case 344). A silicone gel isolates the die surface
and wire bonds from the environment, while allowing the pressure signal to be transmitted to the silicon diaphragm.
The MPX2010/MPXV2010G series pressure sensor oper-
Motorola Sensor Device Data
ating characteristics and internal reliability and qualification
tests are based on use of dry air as the pressure media. Media other than dry air may have adverse effects on sensor
performance and long term reliability. Contact the factory for
information regarding media compatibility in your application.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–25
Freescale Semiconductor, Inc.
MPX2010 MPXV2010G SERIES
LEAST
SQUARE
DEVIATION
LEAST SQUARES FIT
EXAGGERATED
PERFORMANCE
CURVE
RELATIVE VOLTAGE OUTPUT
LINEARITY
Linearity refers to how well a transducer’s output follows
the equation: Vout = Voff + sensitivity x P over the operating
pressure range. There are two basic methods for calculating
nonlinearity: (1) end point straight line fit (see Figure 5) or (2)
a least squares best line fit. While a least squares fit gives
the “best case” linearity error (lower numerical value), the
calculations required are burdensome.
Conversely, an end point fit will give the “worst case” error
(often more desirable in error budget calculations) and the calculations are more straightforward for the user. Motorola’s
specified pressure sensor linearities are based on the end
point straight line method measured at the midrange pressure.
STRAIGHT LINE
DEVIATION
END POINT
STRAIGHT LINE FIT
OFFSET
50
PRESSURE (% FULLSCALE)
Freescale Semiconductor, Inc...
0
100
Figure 4. Linearity Specification Comparison
PRESSURE (P1) / VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing silicone gel which
isolates the die from the environment. The Motorola MPX
Part Number
pressure sensor is designed to operate with positive differential pressure applied, P1 > P2.
The Pressure (P1) side may be identified by using the
table below:
Case Type
Pressure (P1) Side Identifier
MPX2010D
344
Stainless Steel Cap
MPX2010DP
344C
Side with Part Marking
MPX2010GP
344B
Side with Port Attached
MPX2010GS
344E
Side with Port Attached
MPX2010GSX
344F
Side with Port Attached
MPXV2010GP
1369
Side with Port Attached
MPXV2010DP
1351
Side with Part Marking
ORDERING INFORMATION — UNIBODY PACKAGE (MPX2010 SERIES)
MPX Series
Device Type
Options
Order Number
Case Type
Device Marking
Basic Element
Differential
344
MPX2010D
MPX2010D
Ported Elements
Differential, Dual Port
344C
MPX2010DP
MPX2010DP
Gauge
344B
MPX2010GP
MPX2010GP
Gauge, Axial
344E
MPX2010GS
MPX2010D
Gauge, Axial PC Mount
344F
MPX2010GSX
MPX2010D
ORDERING INFORMATION — SMALL OUTLINE PACKAGE (MPXV2010G SERIES)
Device Type
Ported Elements
3–26
Options
Case No.
MPX Series Order No.
Packing Options
Marking
Gauge, Side Port, SMT
1369
MPXV2010GP
Trays
MPXV2010G
Differential, Dual Port, SMT
1351
MPXV2010DP
Trays
MPXV2010G
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
50 kPa
On-Chip Temperature
Compensated & Calibrated
Silicon Pressure Sensors
The MPX2050 series device is a silicon piezoresistive pressure sensors providing a
highly accurate and linear voltage output — directly proportional to the applied pressure.
The sensor is a single, monolithic silicon diaphragm with the strain gauge and a thin–film
resistor network integrated on–chip. The chip is laser trimmed for precise span and offset
calibration and temperature compensation.
MPX2050
SERIES
0 to 50 kPa (0 to 7.25 psi)
40 mV FULL SCALE SPAN
(TYPICAL)
Features
Freescale Semiconductor, Inc...
• Temperature Compensated Over 0°C to + 85°C
• Unique Silicon Shear Stress Strain Gauge
• Easy to Use Chip Carrier Package Options
• Ratiometric to Supply Voltage
• Differential and Gauge Options
MPX2050D
CASE 344
• ± 0.25% Linearity (MPX2050)
Application Examples
• Pump/Motor Controllers
• Robotics
• Level Indicators
• Medical Diagnostics
• Pressure Switching
• Non–Invasive Blood Pressure Measurement
MPX2050GP
CASE 344B
Figure 1 shows a block diagram of the internal circuitry on the stand–alone pressure
sensor chip.
VS
3
THIN FILM
TEMPERATURE
COMPENSATION
AND
CALIBRATION
CIRCUITRY
SENSING
ELEMENT
2
4
Vout+
Vout–
MPX2050DP
CASE 344C
1
GND
Figure 1. Temperature Compensated Pressure Sensor Schematic
VOLTAGE OUTPUT versus APPLIED DIFFERENTIAL PRESSURE
The differential voltage output of the sensor is directly proportional to the differential
pressure applied.
The output voltage of the differential or gauge sensor increases with increasing
pressure applied to the pressure side (P1) relative to the vacuum side (P2). Similarly,
output voltage increases as increasing vacuum is applied to the vacuum side (P2)
relative to the pressure side (P1).
MPX2050GSX
CASE 344F
PIN NUMBER
1
Gnd
3
VS
2
+Vout
4
–Vout
NOTE: Pin 1 is noted by the notch in
the lead.
REV 8
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–27
Freescale Semiconductor, Inc.
MPX2050 SERIES
MAXIMUM RATINGS(NOTE)
Rating
Maximum Pressure (P1 > P2)
Storage Temperature
Operating Temperature
Symbol
Value
Unit
Pmax
200
kPa
Tstg
– 40 to +125
°C
TA
– 40 to +125
°C
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 10 Vdc, TA = 25°C unless otherwise noted, P1 > P2)
Symbol
Min
Typ
Max
Unit
Pressure Range(1)
POP
0
—
50
kPa
Supply Voltage(2)
VS
—
10
16
Vdc
Characteristic
Freescale Semiconductor, Inc...
Supply Current
Io
—
6.0
—
mAdc
Full Scale Span(3)
MPX2050
VFSS
38.5
40
41.5
mV
Offset(4)
MPX2050
Voff
–1.0
—
1.0
mV
∆V/∆P
—
0.8
—
mV/kPa
—
– 0.25
—
0.25
%VFSS
—
—
± 0.1
—
%VFSS
Sensitivity
Linearity(5)
MPX2050
Pressure Hysteresis(5) (0 to 50 kPa)
Temperature Hysteresis(5) (– 40°C to +125°C)
Temperature Effect on Full Scale Span(5)
Temperature Effect on Offset(5)
Input Impedance
—
—
± 0.5
—
%VFSS
TCVFSS
–1.0
—
1.0
%VFSS
TCVoff
–1.0
—
1.0
mV
Zin
1000
—
2500
Ω
Zout
1400
—
3000
Ω
Response Time(6) (10% to 90%)
tR
—
1.0
—
ms
Warm–Up
—
—
20
—
ms
Offset Stability(7)
—
—
± 0.5
—
%VFSS
Output Impedance
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range. Operating the device above the specified excitation range may induce additional
error due to device self–heating.
3. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
4. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
5. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure, using end point method, over the specified
pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation at full rated pressure over the temperature range of 0 to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative
to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Offset stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
3–28
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
LEAST SQUARES FIT
EXAGGERATED
PERFORMANCE
CURVE
RELATIVE VOLTAGE OUTPUT
LINEARITY
Linearity refers to how well a transducer’s output follows
the equation: Vout = Voff + sensitivity x P over the operating
pressure range. There are two basic methods for calculating
nonlinearity: (1) end point straight line fit (see Figure 2) or (2)
a least squares best line fit. While a least squares fit gives
the “best case” linearity error (lower numerical value), the
calculations required are burdensome.
Conversely, an end point fit will give the “worst case” error
(often more desirable in error budget calculations) and the
calculations are more straightforward for the user. Motorola’s
specified pressure sensor linearities are based on the end
point straight line method measured at the midrange pressure.
MPX2050 SERIES
LEAST
SQUARE
DEVIATION
STRAIGHT LINE
DEVIATION
END POINT
STRAIGHT LINE FIT
OFFSET
50
PRESSURE (% FULLSCALE)
100
Figure 2. Linearity Specification Comparison
ON–CHIP TEMPERATURE COMPENSATION and CALIBRATION
Figure 3 shows the minimum, maximum and typical output
characteristics of the MPX2050 series at 25°C. The output is
directly proportional to the differential pressure and is essentially a straight line.
VS = 10 Vdc
TA = 25°C
MPX2050
P1 > P2
40
35
OUTPUT (mVdc)
Freescale Semiconductor, Inc...
0
30
25
20
TYP
SPAN
RANGE
(TYP)
MAX
10
STAINLESS STEEL
METAL COVER
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
DIE
0
12.5
1.8
25
3.6
37.5
5.4
50
7.25
OFFSET
(TYP)
Figure 3. Output versus Pressure Differential
Figure 4 illustrates the differential or gauge configuration
in the basic chip carrier (Case 344). A silicone gel isolates
the die surface and wire bonds from the environment, while
allowing the pressure signal to be transmitted to the silicon
diaphragm.
The MPX2050 series pressure sensor operating charac-
Motorola Sensor Device Data
EPOXY
CASE
WIRE BOND
MIN
5
kPa
PSI
SILICONE
DIE COAT
P1
15
0
–5
The effects of temperature on Full–Scale Span and Offset
are very small and are shown under Operating Characteristics.
LEAD FRAME
P2
RTV DIE
BOND
Figure 4. Cross–Sectional Diagram (not to scale)
teristics and internal reliability and qualification tests are
based on use of dry air as the pressure media. Media other
than dry air may have adverse effects on sensor performance and long term reliability. Contact the factory for information regarding media compatibility in your application.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–29
Freescale Semiconductor, Inc.
MPX2050 SERIES
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing the silicone gel
which isolates the die. The Motorola MPX pressure sensor is
Part Number
designed to operate with positive differential pressure
applied, P1 > P2.
The Pressure (P1) side may be identified by using the
table below:
Case Type
Pressure (P1) Side Identifier
MPX2050D
344
Stainless Steel Cap
MPX2050DP
344C
Side with Part Marking
MPX2050GP
344B
Side with Port Attached
MPX2050GSX
344F
Side with Port Attached
Freescale Semiconductor, Inc...
ORDERING INFORMATION
MPX2050 series pressure sensors are available in differential and gauge configurations. Devices are available in the basic
element package or with pressure port fittings which provide printed circuit board mounting ease and barbed hose pressure
connections.
MPX Series
Device Type
Options
Case Type
Order Number
Device Marking
Basic Element
Differential
344
MPX2050D
MPX2050D
Ported Elements
Differential, Dual Port
344C
MPX2050DP
MPX2050DP
Gauge
344B
MPX2050GP
MPX2050GP
Gauge Axial PC Mount
344F
MPX2050GSX
MPX2050D
3–30
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
50 kPa On-Chip Temperature
Compensated & Calibrated
Silicon Pressure Sensors
The MPX2053/MPXV2053G device is a silicon piezoresistive pressure sensor
providing a highly accurate and linear voltage output — directly proportional to the
applied pressure. The sensor is a single, monolithic silicon diaphragm with the strain
gauge and a thin–film resistor network integrated on–chip. The chip is laser trimmed for
precise span and offset calibration and temperature compensation.
Features
• Temperature Compensated Over 0°C to + 85°C
UNIBODY PACKAGE
MPX2053
MPXV2053G
SERIES
Motorola Preferred Device
0 to 50 kPa (0 to 7.25 psi)
40 mV FULL SCALE SPAN
(TYPICAL)
Freescale Semiconductor, Inc...
• Easy–to–Use Chip Carrier Package Options
• Ratiometric to Supply Voltage
SMALL OUTLINE PACKAGE
SURFACE MOUNT
• Differential and Gauge Options
Application Examples
• Pump/Motor Controllers
MPX2053D
CASE 344
• Robotics
• Level Indicators
• Medical Diagnostics
• Pressure Switching
MPXV2053GP
CASE 1369
• Non–Invasive Blood Pressure Measurement
Figure 1 shows a block diagram of the internal
circuitry on the stand–alone pressure sensor chip.
VS
3
MPX2053GP
CASE 344B
THIN FILM
TEMPERATURE
COMPENSATION
AND
CALIBRATION
CIRCUITRY
SENSING
ELEMENT
2
4
Vout+
MPXV2053DP
CASE 1351
Vout–
PIN NUMBER
1
MPX2053DP
CASE 344C
GND
Figure 1. Temperature Compensated Pressure
Sensor Schematic
Replaces MPX2050/D
REV 3
Motorola Sensor Device Data
Gnd
5
N/C
2
6
N/C
3
+Vout
VS
7
N/C
4
–Vout
8
N/C
NOTE: Pin 1 is noted by the notch in
the lead.
VOLTAGE OUTPUT versus
APPLIED DIFFERENTIAL PRESSURE
The differential voltage output of the sensor is
directly proportional to the differential pressure applied.
The output voltage of the differential or gauge sensor
increases with increasing pressure applied to the
pressure side (P1) relative to the vacuum side (P2).
Similarly, output voltage increases as increasing vacuum is applied to the vacuum side (P2) relative to the
pressure side (P1).
Preferred devices are Motorola recommended choices for future use and
best overall value.
1
MPX2053GSX
CASE 344F
PIN NUMBER
1
Gnd
3
VS
2
+Vout
4
–Vout
MPX2053GVP
CASE 344D
NOTE: Pin 1 is noted by the notch in
the lead.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–31
Freescale Semiconductor, Inc.
MPX2053 MPXV2053G SERIES
MAXIMUM RATINGS(NOTE)
Rating
Maximum Pressure (P1 > P2)
Storage Temperature
Operating Temperature
Symbol
Value
Unit
Pmax
200
kPa
Tstg
– 40 to +125
°C
TA
– 40 to +125
°C
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 10 Vdc, TA = 25°C unless otherwise noted, P1 > P2)
Symbol
Min
Typ
Max
Unit
Pressure Range(1)
POP
0
—
50
kPa
Supply Voltage(2)
VS
—
10
16
Vdc
Characteristic
Supply Current
Io
—
6.0
—
mAdc
VFSS
38.5
40
41.5
mV
Voff
–1.0
—
1.0
mV
Sensitivity
∆V/∆P
—
0.8
—
mV/kPa
Linearity(5)
—
– 0.6
—
0.4
%VFSS
Pressure Hysteresis(5) (0 to 50 kPa)
—
—
± 0.1
—
%VFSS
Freescale Semiconductor, Inc...
Full Scale Span(3)
Offset(4)
Temperature Hysteresis(5) (– 40°C to +125°C)
Temperature Effect on Full Scale Span(5)
Temperature Effect on Offset(5)
Input Impedance
—
—
± 0.5
—
%VFSS
TCVFSS
–2.0
—
2.0
%VFSS
TCVoff
–1.0
—
1.0
mV
Zin
1000
—
2500
Ω
Zout
1400
—
3000
Ω
Response Time(6) (10% to 90%)
tR
—
1.0
—
ms
Warm–Up
—
—
20
—
ms
Offset Stability(7)
—
—
± 0.5
—
%VFSS
Output Impedance
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range. Operating the device above the specified excitation range may induce additional
error due to device self–heating.
3. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
4. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
5. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure, using end point method, over the specified
pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation at full rated pressure over the temperature range of 0 to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative
to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Offset stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
3–32
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, MPX2053
Inc.
MPXV2053G SERIES
LEAST
SQUARE
DEVIATION
LEAST SQUARES FIT
EXAGGERATED
PERFORMANCE
CURVE
RELATIVE VOLTAGE OUTPUT
LINEARITY
Linearity refers to how well a transducer’s output follows
the equation: Vout = Voff + sensitivity x P over the operating
pressure range. There are two basic methods for calculating
nonlinearity: (1) end point straight line fit (see Figure 2) or (2)
a least squares best line fit. While a least squares fit gives
the “best case” linearity error (lower numerical value), the
calculations required are burdensome.
Conversely, an end point fit will give the “worst case” error
(often more desirable in error budget calculations) and the calculations are more straightforward for the user. Motorola’s
specified pressure sensor linearities are based on the end
point straight line method measured at the midrange pressure.
STRAIGHT LINE
DEVIATION
END POINT
STRAIGHT LINE FIT
OFFSET
50
PRESSURE (% FULLSCALE)
100
Figure 2. Linearity Specification Comparison
ON–CHIP TEMPERATURE COMPENSATION and CALIBRATION
Figure 3 shows the minimum, maximum and typical output
characteristics of the MPX2053/MPXV2053G series at 25°C.
The output is directly proportional to the differential pressure
and is essentially a straight line.
VS = 10 Vdc
TA = 25°C
MPX2053
P1 > P2
40
35
OUTPUT (mVdc)
Freescale Semiconductor, Inc...
0
30
25
20
TYP
SPAN
RANGE
(TYP)
MAX
10
STAINLESS STEEL
METAL COVER
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
DIE
0
12.5
1.8
25
3.6
37.5
5.4
50
7.25
OFFSET
(TYP)
Figure 3. Output versus Pressure Differential
Figure 4 illustrates the differential or gauge configuration
in the basic chip carrier (Case 344). A silicone gel isolates
the die surface and wire bonds from the environment, while
allowing the pressure signal to be transmitted to the silicon
diaphragm.
The MPX2053/MPXV2053G series pressure sensor oper-
Motorola Sensor Device Data
EPOXY
CASE
WIRE BOND
MIN
5
kPa
PSI
SILICONE
DIE COAT
P1
15
0
–5
The effects of temperature on Full–Scale Span and Offset
are very small and are shown under Operating Characteristics.
LEAD FRAME
P2
RTV DIE
BOND
Figure 4. Cross–Sectional Diagram (not to scale)
ating characteristics and internal reliability and qualification
tests are based on use of dry air as the pressure media. Media other than dry air may have adverse effects on sensor
performance and long term reliability. Contact the factory for
information regarding media compatibility in your application.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–33
Freescale Semiconductor, Inc.
MPX2053 MPXV2053G SERIES
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing the silicone gel
which isolates the die. The Motorola MPX pressure sensor is
Freescale Semiconductor, Inc...
Part Number
designed to operate with positive differential pressure
applied, P1 > P2.
The Pressure (P1) side may be identified by using the
table below:
Case Type
Pressure (P1) Side Identifier
MPX2053D
344C
Stainless Steel Cap
MPX2053DP
344C
Side with Part Marking
MPX2053GP
344B
Side with Port Attached
MPX2053GSX
344F
Side with Port Attached
MPX2053GVP
344D
Stainless Steel Cap
MPXV2053GP
1369
Side with Port Attached
MPXV2053DP
1351
Side with Part Marking
ORDERING INFORMATION — UNIBODY PACKAGE (MPX2053 SERIES)
MPX Series
Device Type
Options
Order Number
Case Type
Device Marking
Basic Element
Differential
344
MPX2053D
MPX2053D
Ported Elements
Differential, Dual Port
344C
MPX2053DP
MPX2053DP
Gauge
344B
MPX2053GP
MPX2053GP
Gauge, Axial PC Mount
344F
MPX2053GSX
MPX2053D
Gauge, Vacuum
344D
MPX2053GVP
MPX2053GVP
ORDERING INFORMATION — SMALL OUTLINE PACKAGE (MPXV2053G SERIES)
Device Type
Ported Elements
3–34
Options
Case No.
MPX Series Order No.
Packing Options
Marking
Gauge, Side Port, SMT
1369
MPXV2053GP
Trays
MPXV2053G
Differential, Dual Port, SMT
1351
MPXV2053DP
Trays
MPXV2053G
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
Freescale Semiconductor, Inc...
100 kPa
On-Chip Temperature
Compensated & Calibrated
Silicon Pressure Sensors
The MPX2100 series device is a silicon piezoresistive pressure sensor providing a
highly accurate and linear voltage output — directly proportional to the applied pressure.
The sensor is a single, monolithic silicon diaphragm with the strain gauge and a thin–film
resistor network integrated on–chip. The chip is laser trimmed for precise span and offset
calibration and temperature compensation.
Features
• Temperature Compensated Over 0°C to + 85°C
• Easy–to–Use Chip Carrier Package Options
• Available in Absolute, Differential and Gauge Configurations
• Ratiometric to Supply Voltage
• ± 0.25% Linearity (MPX2100D)
Application Examples
• Pump/Motor Controllers
• Robotics
• Level Indicators
• Medical Diagnostics
• Pressure Switching
• Barometers
• Altimeters
MPX2100
SERIES
0 to 100 kPa (0 to 14.5 psi)
40 mV FULL SCALE SPAN
(TYPICAL)
UNIBODY PACKAGE
MPX2100A/D
CASE 344
Figure 1 illustrates a block diagram of the internal circuitry on the stand–alone
pressure sensor chip.
MPX2100AP/GP
CASE 344B
VS
3
THIN FILM
TEMPERATURE
COMPENSATION
AND
CALIBRATION
CIRCUITRY
SENSING
ELEMENT
2
4
Vout+
Vout–
MPX2100DP
CASE 344C
1
GND
Figure 1. Temperature Compensated Pressure Sensor Schematic
VOLTAGE OUTPUT versus APPLIED DIFFERENTIAL PRESSURE
The differential voltage output of the sensor is directly proportional to the differential
pressure applied.
The absolute sensor has a built–in reference vacuum. The output voltage will decrease
as vacuum, relative to ambient, is drawn on the pressure (P1) side.
The output voltage of the differential or gauge sensor increases with increasing
pressure applied to the pressure (P1) side relative to the vacuum (P2) side. Similarly,
output voltage increases as increasing vacuum is applied to the vacuum (P2) side
relative to the pressure (P1) side.
MPX2100ASX/GSX
CASE 344F
PIN NUMBER
1
Gnd
3
VS
2
+Vout
4
–Vout
NOTE: Pin 1 is noted by the notch in
the lead.
REV 9
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–35
Freescale Semiconductor, Inc.
MPX2100 SERIES
MAXIMUM RATINGS(NOTE)
Rating
Symbol
Value
Unit
Pmax
400
kPa
Tstg
– 40 to +125
°C
Operating Temperature
TA
– 40 to +125
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
°C
Maximum Pressure (P1 > P2)
Storage Temperature
OPERATING CHARACTERISTICS (VS = 10 Vdc, TA = 25°C unless otherwise noted, P1 > P2)
Symbol
Min
Typ
Max
Unit
Pressure Range(1)
POP
0
—
100
kPa
Supply Voltage(2)
VS
—
10
16
Vdc
Supply Current
Io
—
6.0
—
mAdc
VFSS
38.5
40
41.5
mV
Voff
–1.0
– 2.0
—
—
1.0
2.0
mV
∆V/∆P
—
0.4
—
mV/kPa
—
—
– 0.25
– 1.0
—
—
0.25
1.0
%VFSS
—
—
± 0.1
—
%VFSS
Freescale Semiconductor, Inc...
Characteristic
Full Scale Span(3)
MPX2100A, MPX2100D
Offset(4)
MPX2100D
MPX2100A Series
Sensitivity
Linearity(5)
MPX2100D Series
MPX2100A Series
Pressure Hysteresis(5) (0 to 100 kPa)
Temperature Hysteresis(5) (– 40°C to +125°C)
Temperature Effect on Full Scale Span(5)
Temperature Effect on Offset(5)
—
—
± 0.5
—
%VFSS
TCVFSS
–1.0
—
1.0
%VFSS
TCVoff
–1.0
—
1.0
mV
Zin
1000
—
2500
Ω
Zout
1400
—
3000
Ω
Response Time(6) (10% to 90%)
tR
—
1.0
—
ms
Warm–Up
—
—
20
—
ms
Offset Stability(7)
—
—
± 0.5
—
%VFSS
Input Impedance
Output Impedance
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range. Operating the device above the specified excitation range may induce additional
error due to device self–heating.
3. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
4. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
5. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure, using end point method, over the specified
pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation at full rated pressure over the temperature range of 0 to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative
to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Offset stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
3–36
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
LINEARITY
Linearity refers to how well a transducer’s output follows
the equation: Vout = Voff + sensitivity x P over the operating
pressure range. There are two basic methods for calculating
nonlinearity: (1) end point straight line fit (see Figure 2) or (2)
a least squares best line fit. While a least squares fit gives
the “best case” linearity error (lower numerical value), the
calculations required are burdensome.
Conversely, an end point fit will give the “worst case” error
(often more desirable in error budget calculations) and the
calculations are more straightforward for the user. Motorola’s
specified pressure sensor linearities are based on the end
point straight line method measured at the midrange
pressure.
MPX2100 SERIES
LEAST SQUARES FIT
RELATIVE VOLTAGE OUTPUT
EXAGGERATED
PERFORMANCE
CURVE
LEAST
SQUARE
DEVIATION
STRAIGHT LINE
DEVIATION
END POINT
STRAIGHT LINE FIT
OFFSET
50
PRESSURE (% FULLSCALE)
100
Figure 2. Linearity Specification Comparison
ON–CHIP TEMPERATURE COMPENSATION and CALIBRATION
The effects of temperature on Full Scale Span and Offset
are very small and are shown under Operating Characteristics.
Figure 3 shows the output characteristics of the MPX2100
series at 25°C. The output is directly proportional to the
differential pressure and is essentially a straight line.
40
VS = 10 Vdc
TA = 25°C
P1 > P2
35
30
OUTPUT (mVdc)
Freescale Semiconductor, Inc...
0
25
20
TYP
SPAN
RANGE
(TYP)
MAX
15
10
MIN
5
kPa
PSI
0
–5
0
25
3.62
50
7.25
75
10.87
100
14.5
OFFSET
(TYP)
Figure 3. Output versus Pressure Differential
SILICONE GEL
DIE COAT
WIRE BOND
DIFFERENTIAL/GAUGE
STAINLESS STEEL
DIE
METAL COVER
P1
EPOXY
CASE
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
LEAD FRAME
DIFFERENTIAL/GAUGE ELEMENT
P2
DIE
BOND
SILICONE GEL ABSOLUTE
DIE COAT
DIE
P1
STAINLESS STEEL
METAL COVER
EPOXY
CASE
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
WIRE BOND
LEAD FRAME
ABSOLUTE ELEMENT
P2
DIE
BOND
Figure 4. Cross–Sectional Diagrams (Not to Scale)
Figure 4 illustrates the absolute sensing configuration
(right) and the differential or gauge configuration in the basic
chip carrier (Case 344). A silicone gel isolates the die surface
and wire bonds from the environment, while allowing the
pressure signal to be transmitted to the silicon diaphragm.
The MPX2100 series pressure sensor operating charac-
Motorola Sensor Device Data
teristics and internal reliability and qualification tests are
based on use of dry air as the pressure media. Media other
than dry air may have adverse effects on sensor performance and long term reliability. Contact the factory for information regarding media compatibility in your application.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–37
Freescale Semiconductor, Inc.
MPX2100 SERIES
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing the silicone gel
which isolates the die. The differential or gauge sensor is
designed to operate with positive differential pressure
applied, P1 > P2. The absolute sensor is designed for
vacuum applied to P1 side.
The Pressure (P1) side may be identified by using the
table below:
Part Number
MPX2100A
Case Type
MPX2100D
Freescale Semiconductor, Inc...
MPX2100DP
Pressure (P1) Side Identifier
344
Stainless Steel Cap
344C
Side with Part Marking
MPX2100AP
MPX2100GP
344B
Side with Port Attached
MPX2100ASX
MPX2100GSX
344F
Side with Port Attached
ORDERING INFORMATION
MPX2100 series pressure sensors are available in absolute, differential and gauge configurations. Devices are available in
the basic element package or with pressure port fittings which provide printed circuit board mounting ease and barbed hose
pressure connections.
MPX Series
Device Type
Options
Case Type
Order Number
Device Marking
Basic Element
Absolute, Differential
344
MPX2100A
MPX2100D
MPX2100A
MPX2100D
Ported Elements
Differential, Dual Port
344C
MPX2100DP
MPX2100DP
Absolute, Gauge
344B
MPX2100AP
MPX2100GP
MPX2100AP
MPX2100GP
Absolute, Gauge Axial
344F
MPX2100ASX
MPX2100GSX
MPX2100A
MPX2100D
3–38
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
Freescale Semiconductor, Inc...
100 kPa On-Chip Temperature
Compensated & Calibrated
Silicon Pressure Sensors
The MPX2102/MPXV2102G series device is a silicon piezoresistive pressure sensor
providing a highly accurate and linear voltage output — directly proportional to the
applied pressure. The sensor is a single, monolithic silicon diaphragm with the strain
gauge and a thin–film resistor network integrated on–chip. The chip is laser trimmed for
precise span and offset calibration and temperature compensation.
Features
• Temperature Compensated Over 0°C to + 85°C
UNIBODY PACKAGE
• Easy–to–Use Chip Carrier Package Options
• Available in Absolute, Differential and Gauge Configurations
• Ratiometric to Supply Voltage
Application Examples
• Pump/Motor Controllers
MPX2102A/D
• Robotics
CASE 344
• Level Indicators
• Medical Diagnostics
• Pressure Switching
• Barometers
• Altimeters
MPX2102
MPXV2102G
SERIES
Motorola Preferred Device
0 to 100 kPa (0 to 14.5 psi)
40 mV FULL SCALE SPAN
(TYPICAL)
SMALL OUTLINE PACKAGE
SURFACE MOUNT
MPXV2102GP
CASE 1369
Figure 1 illustrates a block diagram of the internal
circuitry on the stand–alone pressure sensor chip.
VS
3
THIN FILM
TEMPERATURE
COMPENSATION
AND
CALIBRATION
CIRCUITRY
SENSING
ELEMENT
MPX2102AP/GP
CASE 344B
2
4
Vout+
MPXV2102DP
CASE 1351
Vout–
1
PIN NUMBER
GND
Figure 1. Temperature Compensated Pressure
Sensor Schematic
MPX2102DP
CASE 344C
VOLTAGE OUTPUT versus
APPLIED DIFFERENTIAL PRESSURE
The differential voltage output of the sensor is
directly proportional to the differential pressure applied.
The absolute sensor has a built–in reference vacuum. The output voltage will decrease as vacuum,
relative to ambient, is drawn on the pressure (P1) side.
The output voltage of the differential or gauge sensor
increases with increasing pressure applied to the
pressure (P1) side relative to the vacuum (P2) side.
Similarly, output voltage increases as increasing vacuum is applied to the vacuum (P2) side relative to the
pressure (P1) side.
Preferred devices are Motorola recommended choices for future use
and best overall value.
REV 2
Motorola Sensor Device Data
1
Gnd
5
N/C
2
+Vout
VS
6
N/C
3
7
N/C
4
–Vout
8
N/C
NOTE: Pin 1 is noted by the notch in
the lead.
MPX2102ASX/GSX
CASE 344F
PIN NUMBER
1
Gnd
3
VS
2
+Vout
4
–Vout
MPX2102GVP
CASE 344D
NOTE: Pin 1 is noted by the notch in
the lead.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–39
Freescale Semiconductor, Inc.
MPX2102 MPXV2102G SERIES
MAXIMUM RATINGS(NOTE)
Rating
Symbol
Value
Unit
Pmax
400
kPa
Tstg
– 40 to +125
°C
Operating Temperature
TA
– 40 to +125
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
°C
Maximum Pressure (P1 > P2)
Storage Temperature
OPERATING CHARACTERISTICS (VS = 10 Vdc, TA = 25°C unless otherwise noted, P1 > P2)
Symbol
Min
Typ
Max
Unit
Pressure Range(1)
POP
0
—
100
kPa
Supply Voltage(2)
VS
—
10
16
Vdc
Supply Current
Io
—
6.0
—
mAdc
VFSS
38.5
40
41.5
mV
Voff
–1.0
– 2.0
—
—
1.0
2.0
mV
∆V/∆P
—
0.4
—
mV/kPa
—
—
– 0.6
– 1.0
—
—
0.4
1.0
%VFSS
—
—
± 0.1
—
%VFSS
Characteristic
Full Scale Span(3)
Freescale Semiconductor, Inc...
Offset(4)
MPX2102D Series
MPX2102A Series
Sensitivity
Linearity(5)
MPX2102D Series
MPX2102A Series
Pressure Hysteresis(5) (0 to 100 kPa)
Temperature Hysteresis(5) (– 40°C to +125°C)
Temperature Effect on Full Scale Span(5)
Temperature Effect on Offset(5)
—
—
± 0.5
—
%VFSS
TCVFSS
–2.0
—
2.0
%VFSS
TCVoff
–1.0
—
1.0
mV
Zin
1000
—
2500
Ω
Zout
1400
—
3000
Ω
Response Time(6) (10% to 90%)
tR
—
1.0
—
ms
Warm–Up
—
—
20
—
ms
Offset Stability(7)
—
—
± 0.5
—
%VFSS
Input Impedance
Output Impedance
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range. Operating the device above the specified excitation range may induce additional
error due to device self–heating.
3. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
4. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
5. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure, using end point method, over the specified
pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation at full rated pressure over the temperature range of 0 to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative
to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Offset stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
3–40
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, MPX2102
Inc.
MPXV2102G SERIES
LINEARITY
Linearity refers to how well a transducer’s output follows
the equation: Vout = Voff + sensitivity x P over the operating
pressure range. There are two basic methods for calculating
nonlinearity: (1) end point straight line fit (see Figure 2) or (2)
a least squares best line fit. While a least squares fit gives
the “best case” linearity error (lower numerical value), the
calculations required are burdensome.
Conversely, an end point fit will give the “worst case” error
(often more desirable in error budget calculations) and the
calculations are more straightforward for the user.
Motorola’s specified pressure sensor linearities are based on
the end point straight line method measured at the midrange
pressure.
LEAST
SQUARE
DEVIATION
LEAST SQUARES FIT
RELATIVE VOLTAGE OUTPUT
EXAGGERATED
PERFORMANCE
CURVE
STRAIGHT LINE
DEVIATION
END POINT
STRAIGHT LINE FIT
OFFSET
50
PRESSURE (% FULLSCALE)
100
Figure 2. Linearity Specification Comparison
ON–CHIP TEMPERATURE COMPENSATION and CALIBRATION
The effects of temperature on Full Scale Span and Offset
are very small and are shown under Operating Characteristics.
Figure 3 shows the output characteristics of the
MPX2102/MPXV2102G series at 25°C. The output is
directly proportional to the differential pressure and is
essentially a straight line.
40
VS = 10 Vdc
TA = 25°C
P1 > P2
35
30
OUTPUT (mVdc)
Freescale Semiconductor, Inc...
0
25
20
TYP
SPAN
RANGE
(TYP)
MAX
15
10
MIN
5
kPa
PSI
0
–5
0
25
3.62
50
7.25
75
10.87
100
14.5
OFFSET
(TYP)
Figure 3. Output versus Pressure Differential
SILICONE GEL
DIE COAT
WIRE BOND
DIFFERENTIAL/GAUGE
STAINLESS STEEL
DIE
METAL COVER
P1
EPOXY
CASE
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
LEAD FRAME
DIFFERENTIAL/GAUGE ELEMENT
P2
DIE
BOND
SILICONE GEL ABSOLUTE
DIE COAT
DIE
P1
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
WIRE BOND
LEAD FRAME
ABSOLUTE ELEMENT
P2
STAINLESS STEEL
METAL COVER
EPOXY
CASE
DIE
BOND
Figure 4. Cross–Sectional Diagrams (Not to Scale)
Figure 4 illustrates the absolute sensing configuration
(right) and the differential or gauge configuration in the basic
chip carrier (Case 344). A silicone gel isolates the die
surface and wire bonds from the environment, while allowing
the pressure signal to be transmitted to the silicon
diaphragm.
Motorola Sensor Device Data
The MPX2102/MPXV2102G series pressure sensor operating characteristics and internal reliability and qualification
tests are based on use of dry air as the pressure media. Media other than dry air may have adverse effects on sensor
performance and long term reliability. Contact the factory for
information regarding media compatibility in your application.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–41
Freescale Semiconductor, Inc.
MPX2102 MPXV2102G SERIES
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing the silicone gel
which isolates the die. The differential or gauge sensor is
designed to operate with positive differential pressure
Part Number
MPX2102A
Case Type
MPX2102D
Pressure (P1) Side Identifier
344
Stainless Steel Cap
344C
Side with Part Marking
344B
Side with Port Attached
344D
Stainless Steel Cap
344F
Side with Port Attached
MPXV2102GP
1369
Side with Port Attached
MPXV2102DP
1351
Side with Part Marking
MPX2102DP
MPX2102AP
MPX2102GP
MPX2102GVP
MPX2102ASX
Freescale Semiconductor, Inc...
applied, P1 > P2. The absolute sensor is designed for
vacuum applied to P1 side.
The Pressure (P1) side may be identified by using the
table below:
MPX2102GSX
ORDERING INFORMATION — UNIBODY PACKAGE (MPX2102 SERIES)
MPX Series
Device Type
Options
Order Number
Case Type
Device Marking
Basic Element
Absolute, Differential
344
MPX2102A
MPX2102D
MPX2102A
MPX2102D
Ported Elements
Differential, Dual Port
344C
MPX2102DP
MPX2102DP
Absolute, Gauge
344B
MPX2102AP
MPX2102GP
MPX2102AP
MPX2102GP
Absolute, Gauge Axial
344F
MPX2102ASX
MPX2102GSX
MPX2102A
MPX2102D
Gauge, Vacuum
344D
MPX2102GVP
MPX2102GVP
ORDERING INFORMATION — SMALL OUTLINE PACKAGE (MPXV2102G SERIES)
Device Type
Ported Elements
3–42
Options
Case No.
MPX Series Order No.
Packing Options
Marking
Gauge, Side Port, SMT
1369
MPXV2102GP
Trays
MPXV2102G
Differential, Dual Port, SMT
1351
MPXV2102DP
Trays
MPXV2102G
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
Freescale Semiconductor, Inc...
200 kPa On-Chip Temperature
Compensated & Calibrated
Pressure Sensors
The MPX2200 series device is a silicon piezoresistive pressure sensor providing a
highly accurate and linear voltage output — directly proportional to the applied pressure.
The sensor is a single monolithic silicon diaphragm with the strain gauge and a thin–film
resistor network integrated on–chip. The chip is laser trimmed for precise span and
offset calibration and temperature compensation. They are designed for use in
applications such as pump/motor controllers, robotics, level indicators, medical
diagnostics, pressure switching, barometers, altimeters, etc.
Features
• Temperature Compensated Over 0°C to + 85°C
• ± 0.25% Linearity (MPX2200D)
• Easy–to–Use Chip Carrier Package Options
• Available in Absolute, Differential and Gauge Configurations
Application Examples
• Pump/Motor Controllers
• Robotics
• Level Indicators
• Medical Diagnostics
• Pressure Switching
• Barometers
• Altimeters
MPX2200
SERIES
0 to 200 kPa (0 to 29 psi)
40 mV FULL SCALE SPAN
(TYPICAL)
UNIBODY PACKAGE
MPX2200A/D
CASE 344
Figure 1 illustrates a block diagram of the internal circuitry on the stand–alone
pressure sensor chip.
VS
3
MPX2200AP/GP
CASE 344B
THIN FILM
TEMPERATURE
COMPENSATION
AND
CALIBRATION
CIRCUITRY
SENSING
ELEMENT
2
4
Vout+
Vout–
1
MPX2200DP
CASE 344C
GND
Figure 1. Temperature Compensated Pressure Sensor Schematic
VOLTAGE OUTPUT versus APPLIED DIFFERENTIAL PRESSURE
The differential voltage output of the sensor is directly proportional to the differential
pressure applied.
The absolute sensor has a built–in reference vacuum. The output voltage will
decrease as vacuum, relative to ambient, is drawn on the pressure (P1) side.
The output voltage of the differential or gauge sensor increases with increasing
pressure applied to the pressure (P1) side relative to the vacuum (P2) side. Similarly,
output voltage increases as increasing vacuum is applied to the vacuum (P2) side
relative to the pressure (P1) side.
MPX2200GVP
CASE 344D
PIN NUMBER
1
Gnd
3
VS
2
+Vout
4
–Vout
NOTE: Pin 1 is noted by the notch in
the lead.
REV 9
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–43
Freescale Semiconductor, Inc.
MPX2200 SERIES
MAXIMUM RATINGS(NOTE)
Rating
Symbol
Value
Unit
Pmax
800
kPa
Tstg
– 40 to +125
°C
Operating Temperature
TA
– 40 to +125
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
°C
Maximum Pressure (P1 > P2)
Storage Temperature
OPERATING CHARACTERISTICS (VS = 10 Vdc, TA = 25°C unless otherwise noted, P1 > P2)
Symbol
Min
Typ
Max
Unit
0
—
200
kPa
Supply Voltage
POP
VS
—
10
16
Vdc
Supply Current
Io
—
6.0
—
mAdc
VFSS
Voff
38.5
40
41.5
mV
–1.0
—
1.0
mV
∆V/∆P
—
0.2
—
mV/kPa
—
– 0.25
– 1.0
—
—
0.25
1.0
%VFSS
—
—
± 0.1
—
%VFSS
%VFSS
Characteristics
Pressure Range(1)
Freescale Semiconductor, Inc...
Full Scale Span(3)
Offset(4)
Sensitivity
Linearity(5)
MPX2200D Series
MPX2200A Series
Pressure Hysteresis(5) (0 to 200 kPa)
Temperature Hysteresis(5) (– 40°C to +125°C)
—
—
± 0.5
—
TCVFSS
TCVoff
–1.0
—
1.0
–1.0
—
1.0
%VFSS
mV
Zin
Zout
1300
—
2500
Ω
1400
—
3000
Ω
—
1.0
—
ms
Warm–Up
tR
—
—
20
—
ms
Offset Stability(7)
—
—
± 0.5
—
%VFSS
Temperature Effect on Full Scale Span(5)
Temperature Effect on Offset(5)
Input Impedance
Output Impedance
Response Time(6) (10% to 90%)
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range. Operating the device above the specified excitation range may induce additional
error due to device self–heating.
3. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
4. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
5. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure, using end point method, over the specified
pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation at full rated pressure over the temperature range of 0 to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative
to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Offset stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
3–44
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
LINEARITY
Linearity refers to how well a transducer’s output follows
the equation: Vout = Voff + sensitivity x P over the operating
pressure range. There are two basic methods for calculating
nonlinearity: (1) end point straight line fit (see Figure 2) or (2)
a least squares best line fit. While a least squares fit gives
the “best case” linearity error (lower numerical value), the
calculations required are burdensome.
Conversely, an end point fit will give the “worst case” error
(often more desirable in error budget calculations) and the
calculations are more straightforward for the user. Motorola’s specified pressure sensor linearities are based on the
end point straight line method measured at the midrange
pressure.
MPX2200 SERIES
LEAST SQUARES FIT
RELATIVE VOLTAGE OUTPUT
EXAGGERATED
PERFORMANCE
CURVE
LEAST
SQUARE
DEVIATION
STRAIGHT LINE
DEVIATION
END POINT
STRAIGHT LINE FIT
OFFSET
50
PRESSURE (% FULLSCALE)
100
Figure 2. Linearity Specification Comparison
ON–CHIP TEMPERATURE COMPENSATION and CALIBRATION
The effects of temperature on Full Scale Span and Offset
are very small and are shown under Operating Characteristics.
Figure 3 shows the output characteristics of the MPX2200
series at 25°C. The output is directly proportional to the differential pressure and is essentially a straight line.
VS = 10 Vdc
TA = 25°C
P1 > P2
40
35
OUTPUT (mVdc)
Freescale Semiconductor, Inc...
0
TYP
30
25
SPAN
RANGE
(TYP)
MAX
20
15
10
MIN
5
0
–5
kPa 0
PSI
25
50
7.25
75
100
14.5
150
21.75
125
175
200
29
OFFSET
PRESSURE
Figure 3. Output versus Pressure Differential
SILICONE GEL
DIE COAT
DIFFERENTIAL/GAUGE
STAINLESS STEEL
DIE
METAL COVER
P1
EPOXY
CASE
ÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉ
WIRE BOND
LEAD FRAME
DIFFERENTIAL/GAUGE ELEMENT
P2
DIE
BOND
SILICONE GEL ABSOLUTE
DIE COAT
DIE
P1
STAINLESS STEEL
METAL COVER
EPOXY
CASE
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
WIRE BOND
LEAD FRAME
ABSOLUTE ELEMENT
P2
DIE
BOND
Figure 4. Cross–Sectional Diagrams (Not to Scale)
Figure 4 illustrates an absolute sensing die (right) and the
differential or gauge die in the basic chip carrier (Case 344).
A silicone gel isolates the die surface and wire bonds from
the environment, while allowing the pressure signal to be
transmitted to the silicon diaphragm.
The MPX2200 series pressure sensor operating charac-
Motorola Sensor Device Data
teristics and internal reliability and qualification tests are
based on use of dry air as the pressure media. Media other
than dry air may have adverse effects on sensor performance and long term reliability. Contact the factory for information regarding media compatibility in your application.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–45
Freescale Semiconductor, Inc.
MPX2200 SERIES
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing the silicone gel
which isolates the die from the environment. The differential
or gauge sensor is designed to operate with positive differenPart Number
MPX2200A
Case Type
MPX2200D
MPX2200DP
MPX2200AP
MPX2200GP
MPX2200GVP
Freescale Semiconductor, Inc...
tial pressure applied, P1 > P2. The absolute sensor is
designed for vacuum applied to P1 side.
The Pressure (P1) side may be identified by using the
table below:
Pressure (P1) Side Identifier
344
Stainless Steel Cap
344C
Side with Part Marking
344B
Side with Port Attached
344D
Stainless Steel Cap
ORDERING INFORMATION
MPX2200 series pressure sensors are available in absolute, differential and gauge configurations. Devices are available in
the basic element package or with pressure port fittings which provide printed circuit board mounting ease and barbed hose
pressure connections.
MPX Series
Device Type
Options
Case Type
Order Number
Device Marking
Basic Element
Absolute, Differential
344
MPX2200A
MPX2200D
MPX2200A
MPX2200D
Ported Elements
Differential
344C
MPX2200DP
MPX2200DP
Absolute, Gauge
344B
MPX2200AP
MPX2200GP
MPX2200AP
MPX2200GP
Gauge, Vacuum
344D
MPX2200GVP
MPX2200GVP
3–46
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
Freescale Semiconductor, Inc...
200 kPa On-Chip Temperature
Compensated & Calibrated
Pressure Sensors
MPX2202
MPXV2202G
SERIES
The MPX2202/MPXV2202G device series is a silicon piezoresistive pressure sensor
providing a highly accurate and linear voltage output — directly proportional to the
applied pressure. The sensor is a single monolithic silicon diaphragm with the strain
gauge and a thin–film resistor network integrated on–chip. The chip is laser trimmed for
precise span and offset calibration and temperature compensation. They are designed
for use in applications such as pump/motor controllers, robotics, level indicators, medical
diagnostics, pressure switching, barometers, altimeters, etc.
Features
UNIBODY PACKAGE
• Temperature Compensated Over 0°C to + 85°C
• Easy–to–Use Chip Carrier Package Options
• Available in Absolute, Differential and Gauge Configurations
Application Examples
• Pump/Motor Controllers
• Robotics
MPX2202A/D
CASE 344
• Level Indicators
• Medical Diagnostics
• Pressure Switching
• Barometers
• Altimeters
Motorola Preferred Device
0 to 200 kPa (0 to 29 psi)
40 mV FULL SCALE SPAN
(TYPICAL)
SMALL OUTLINE PACKAGE
SURFACE MOUNT
MPXV2202GP
CASE 1369
Figure 1 illustrates a block diagram of the internal
circuitry on the stand–alone pressure sensor chip.
VS
3
THIN FILM
TEMPERATURE
COMPENSATION
AND
CALIBRATION
CIRCUITRY
SENSING
ELEMENT
2
4
MPX2202AP/GP
CASE 344B
Vout+
MPXV2202DP
CASE 1351
Vout–
PIN NUMBER
1
GND
Figure 1. Temperature Compensated Pressure
Sensor Schematic
VOLTAGE OUTPUT versus
APPLIED DIFFERENTIAL PRESSURE
The differential voltage output of the sensor is
directly proportional to the differential pressure applied.
The absolute sensor has a built–in reference vacuum. The output voltage will decrease as vacuum,
relative to ambient, is drawn on the pressure (P1) side.
The output voltage of the differential or gauge sensor
increases with increasing pressure applied to the
pressure (P1) side relative to the vacuum (P2) side.
Similarly, output voltage increases as increasing vacuum is applied to the vacuum (P2) side relative to the
pressure (P1) side.
Preferred devices are Motorola recommended choices for future use
and best overall value.
Replaces MPX2200/D
MPX2202DP
CASE 344C
1
Gnd
5
N/C
2
+Vout
VS
6
N/C
3
7
N/C
4
–Vout
8
N/C
NOTE: Pin 1 is noted by the notch in
the lead.
MPX2202ASX/GSX
CASE 344F
PIN NUMBER
1
Gnd
3
VS
2
+Vout
4
–Vout
MPX2202GVP
CASE 344D
NOTE: Pin 1 is noted by the notch in
the lead.
REV 2
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–47
Freescale Semiconductor, Inc.
MPX2202 MPXV2202G SERIES
MAXIMUM RATINGS(NOTE)
Rating
Symbol
Value
Unit
Pmax
800
kPa
Tstg
– 40 to +125
°C
Operating Temperature
TA
– 40 to +125
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
°C
Maximum Pressure (P1 > P2)
Storage Temperature
OPERATING CHARACTERISTICS (VS = 10 Vdc, TA = 25°C unless otherwise noted, P1 > P2)
Symbol
Min
Typ
Max
Unit
0
—
200
kPa
Supply Voltage
POP
VS
—
10
16
Vdc
Supply Current
Io
—
6.0
—
mAdc
VFSS
Voff
38.5
40
41.5
mV
–1.0
—
1.0
mV
∆V/∆P
—
0.2
—
mV/kPa
—
– 0.6
– 1.0
—
—
0.4
1.0
%VFSS
—
—
± 0.1
—
%VFSS
%VFSS
Characteristics
Pressure Range(1)
Freescale Semiconductor, Inc...
Full Scale Span(3)
Offset(4)
Sensitivity
Linearity(5)
MPX2202D Series
MPX2202A Series
Pressure Hysteresis(5) (0 to 200 kPa)
Temperature Hysteresis(5) (– 40°C to +125°C)
—
—
± 0.5
—
TCVFSS
TCVoff
–2.0
—
2.0
–1.0
—
1.0
%VFSS
mV
Zin
Zout
1000
—
2500
Ω
1400
—
3000
Ω
—
1.0
—
ms
Warm–Up
tR
—
—
20
—
ms
Offset Stability(7)
—
—
± 0.5
—
%VFSS
Temperature Effect on Full Scale Span(5)
Temperature Effect on Offset(5)
Input Impedance
Output Impedance
Response Time(6) (10% to 90%)
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range. Operating the device above the specified excitation range may induce additional
error due to device self–heating.
3. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
4. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
5. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure, using end point method, over the specified
pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation at full rated pressure over the temperature range of 0 to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative
to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Offset stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
3–48
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, MPX2202
Inc.
MPXV2202G SERIES
LINEARITY
Linearity refers to how well a transducer’s output follows
the equation: Vout = Voff + sensitivity x P over the operating
pressure range. There are two basic methods for calculating
nonlinearity: (1) end point straight line fit (see Figure 2) or (2)
a least squares best line fit. While a least squares fit gives
the “best case” linearity error (lower numerical value), the
calculations required are burdensome.
Conversely, an end point fit will give the “worst case” error
(often more desirable in error budget calculations) and the
calculations are more straightforward for the user. Motorola’s
specified pressure sensor linearities are based on the end
point straight line method measured at the midrange
pressure.
LEAST
SQUARE
DEVIATION
LEAST SQUARES FIT
RELATIVE VOLTAGE OUTPUT
EXAGGERATED
PERFORMANCE
CURVE
STRAIGHT LINE
DEVIATION
END POINT
STRAIGHT LINE FIT
OFFSET
50
PRESSURE (% FULLSCALE)
100
Figure 2. Linearity Specification Comparison
ON–CHIP TEMPERATURE COMPENSATION and CALIBRATION
straight line.
The effects of temperature on Full Scale Span and Offset
are very small and are shown under Operating Characteristics.
Figure 3 shows the output characteristics of the
MPX2202/MPXV2202G series at 25°C. The output is directly
proportional to the differential pressure and is essentially a
VS = 10 Vdc
TA = 25°C
P1 > P2
40
35
OUTPUT (mVdc)
Freescale Semiconductor, Inc...
0
TYP
30
25
SPAN
RANGE
(TYP)
MAX
20
15
10
MIN
5
0
–5
kPa 0
PSI
25
50
7.25
75
100
14.5
150
21.75
125
175
200
29
OFFSET
PRESSURE
Figure 3. Output versus Pressure Differential
SILICONE GEL
DIE COAT
DIFFERENTIAL/GAUGE
STAINLESS STEEL
DIE
METAL COVER
P1
EPOXY
CASE
ÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉ
WIRE BOND
LEAD FRAME
DIFFERENTIAL/GAUGE ELEMENT
P2
DIE
BOND
SILICONE GEL ABSOLUTE
DIE COAT
DIE
P1
STAINLESS STEEL
METAL COVER
EPOXY
CASE
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
WIRE BOND
LEAD FRAME
ABSOLUTE ELEMENT
P2
DIE
BOND
Figure 4. Cross–Sectional Diagrams (Not to Scale)
Figure 4 illustrates an absolute sensing die (right) and the
differential or gauge die in the basic chip carrier (Case 344).
A silicone gel isolates the die surface and wire bonds from
the environment, while allowing the pressure signal to be
transmitted to the silicon diaphragm.
The MPX2202/MPXV2202G series pressure sensor oper-
Motorola Sensor Device Data
ating characteristics and internal reliability and qualification
tests are based on use of dry air as the pressure media. Media other than dry air may have adverse effects on sensor
performance and long term reliability. Contact the factory for
information regarding media compatibility in your application.
www.motorola.com/semiconductors
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Information On This Product,
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3–49
Freescale Semiconductor, Inc.
MPX2202 MPXV2202G SERIES
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing the silicone gel
which isolates the die from the environment. The differential
or gauge sensor is designed to operate with positive differenPart Number
MPX2202A
tial pressure applied, P1 > P2. The absolute sensor is
designed for vacuum applied to P1 side.
The Pressure (P1) side may be identified by using the
table below:
Case Type
MPX2202D
MPX2202DP
MPX2202AP
MPX2202GP
MPX2202GVP
Freescale Semiconductor, Inc...
MPX2202ASX
MPX2202GSX
Pressure (P1) Side Identifier
344
Stainless Steel Cap
344C
Side with Part Marking
344B
Side with Port Attached
344D
Stainless Steel Cap
344F
Side with Port Attached
MPXV2202GP
1369
Side with Port Attached
MPXV2202DP
1351
Side with Part Marking
ORDERING INFORMATION — UNIBODY PACKAGE (MPX2202 SERIES)
MPX Series
Device Type
Options
Case Type
Order Number
Device Marking
Basic Element
Absolute, Differential
344
MPX2202A
MPX2202D
MPX2202A
MPX2202D
Ported Elements
Differential, Dual Port
344C
MPX2202DP
MPX2202DP
Absolute, Gauge
344B
MPX2202AP
MPX2202GP
MPX2202AP
MPX2202GP
Absolute, Gauge Axial
344F
MPX2202ASX
MPX2202GSX
MPX2202A
MPX2202D
Gauge, Vacuum
344D
MPX2202GVP
MPX2202GVP
ORDERING INFORMATION — SMALL OUTLINE PACKAGE (MPXV2202G SERIES)
Device Type
Ported Elements
3–50
Options
Case No.
MPX Series Order No.
Packing Options
Marking
Gauge, Side Port, SMT
1369
MPXV2202GP
Trays
MPXV2202G
Differential, Dual Port, SMT
1351
MPXV2202DP
Trays
MPXV2202G
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Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
High Volume Pressure Sensor
For Disposable Applications
Motorola has developed a low cost, high volume, miniature pressure sensor package
which is ideal as a sub–module component or a disposable unit. The unique concept of
the Chip Pak allows great flexibility in system design while allowing an economic solution
for the designer. This new chip carrier package uses Motorola’s unique sensor die with
its piezoresistive technology, along with the added feature of on–chip, thin–film
temperature compensation and calibration.
NOTE: Motorola is also offering the Chip Pak package in application–specific
configurations, which will have an “SPX” prefix, followed by a four–digit number, unique
to the specific customer.
MPX2300DT1
MPX2301DT1
Motorola Preferred Device
PRESSURE SENSORS
0 to 300 mmHg (0 to 40 kPa)
Freescale Semiconductor, Inc...
Features
• Low Cost
CHIP PAK PACKAGE
• Integrated Temperature Compensation and Calibration
• Ratiometric to Supply Voltage
• Polysulfone Case Material (Medical, Class V Approved)
• Provided in Easy–to–Use Tape and Reel
MPX2300/1DT1
CASE 423A
Application Examples
• Medical Diagnostics
• Infusion Pumps
• Blood Pressure Monitors
PIN NUMBER
• Pressure Catheter Applications
1
VS
3
S–
• Patient Monitoring
2
S+
4
Gnd
NOTE: The die and wire bonds are exposed on the front side of the Chip Pak
(pressure is applied to the backside of the device). Front side die and wire protection
must be provided in the customer’s housing. Use caution when handling the devices
during all processes.
Motorola’s MPX2300DT1/MPX2301DT1 Pressure Sensors have been designed for medical usage by combining
the performance of Motorola’s shear stress pressure sensor
design and the use of biomedically approved materials.
Materials with a proven history in medical situations have
been chosen to provide a sensor that can be used with
confidence in applications, such as invasive blood pressure
monitoring. It can be sterilized using ethylene oxide. The
portions of the pressure sensor that are required to be
biomedically approved are the rigid housing and the gel
coating.
The rigid housing is molded from a white, medical grade
polysulfone that has passed extensive biological testing
including: tissue culture test, rabbit implant, hemolysis,
intracutaneous test in rabbits, and system toxicity, USP.
A silicone dielectric gel covers the silicon piezoresistive
sensing element. The gel is a nontoxic, nonallergenic elastomer system which meets all USP XX Biological Testing Class
V requirements. The properties of the gel allow it to transmit
pressure uniformly to the diaphragm surface, while isolating
the internal electrical connections from the corrosive effects
of fluids, such as saline solution. The gel provides electrical
isolation sufficient to withstand defibrillation testing, as specified in the proposed Association for the Advancement of
Medical Instrumentation (AAMI) Standard for blood pressure
transducers. A biomedically approved opaque filler in the gel
prevents bright operating room lights from affecting the performance of the sensor. The MPX2301DT1 is a reduced gel
option.
Preferred devices are Motorola recommended choices for future use and best overall value.
REV 5
Motorola Sensor Device Data
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MPX2300DT1 MPX2301DT1Freescale Semiconductor, Inc.
MAXIMUM RATINGS(NOTE)
Rating
Maximum Pressure (Backside)
Storage Temperature
Operating Temperature
Symbol
Value
Unit
Pmax
125
PSI
Tstg
– 25 to + 85
°C
TA
+ 15 to + 40
°C
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 6 Vdc, TA = 25°C unless otherwise noted)
Characteristics
Pressure Range
Min
Typ
Max
Unit
POP
0
—
300
mmHg
Supply Voltage(7)
VS
—
6.0
10
Vdc
Supply Current
Io
—
1.0
—
mAdc
Voff
– 0.75
—
0.75
mV
—
4.95
5.0
5.05
µV/V/mmHg
VFSS
2.976
3.006
3.036
mV
Linearity + Hysteresis(2)
—
– 1.5
—
1.5
%VFSS
Accuracy(9) VS = 6 V, P = 101 to 200 mmHg
—
– 1.5
—
1.5
%
Accuracy(9) VS = 6 V, P = 201 to 300 mmHg
—
– 3.0
—
3.0
%
Zero Pressure Offset
Freescale Semiconductor, Inc...
Symbol
Sensitivity
Full Scale Span(1)
Temperature Effect on Sensitivity
TCS
– 0.1
—
+ 0.1
%/°C
TCVFSS
– 0.1
—
+ 0.1
%/°C
TCVoff
– 9.0
—
+ 9.0
µV/°C
Zin
1800
—
4500
Ω
Output Impedance
Zout
270
—
330
Ω
RCAL (150 kΩ)(8)
RCAL
97
100
103
mmHg
Response Time(5)
(10% to 90%)
tR
—
1.0
—
ms
Temperature Error Band
—
0
—
85
°C
Stability(6)
—
—
± 0.5
—
%VFSS
Temperature Effect on Full Scale Span(3)
Temperature Effect on Offset(4)
Input Impedance
NOTES:
1. Measured at 6.0 Vdc excitation for 100 mmHg pressure differential. VFSS and FSS are like terms representing the algebraic difference
between full scale output and zero pressure offset.
2. Maximum deviation from end–point straight line fit at 0 and 200 mmHg.
3. Slope of end–point straight line fit to full scale span at 15°C and + 40°C relative to + 25°C.
4. Slope of end–point straight line fit to zero pressure offset at 15°C and + 40°C relative to + 25°C.
5. For a 0 to 300 mmHg pressure step change.
6. Stability is defined as the maximum difference in output at any pressure within POP and temperature within +10°C to + 85°C after:
a. 1000 temperature cycles, – 40°C to +125°C.
b. 1.5 million pressure cycles, 0 to 300 mmHg.
7. Recommended voltage supply: 6 V ± 0.2 V, regulated. Sensor output is ratiometric to the voltage supply. Supply voltages above +10 V may
induce additional error due to device self–heating.
8. Offset measurement with respect to the measured sensitivity when a 150k ohm resistor is connected to VS and S+ output.
9. Accuracy is calculated using the following equation:
Errorp = {[Vp – Offset)/(SensNom*VEX)]–P}/P
Where:
Vp = Actual output voltage at pressure P in microvolts (µV)
Offset = Voltage output at P = 0mmHg in microvolts (µV)
SensNom = Nominal sensitivity = 5.01 µV/V/mmHg
VEX = Excitation voltage
P = Pressure applied to the device
3–52
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPX2300DT1 MPX2301DT1
ORDERING INFORMATION
The MPX2300DT1/MPX2301DT1 silicon pressure sensors are available in tape and reel packaging.
Device Type/Order No.
Case No.
Device Description
Marking
MPX2300DT1
423A
Chip Pak, Full Gel
Date Code, Lot ID
MPX2301DT1
423A
Chip Pak, 1/3 Gel
Date Code, Lot ID
Packaging Information
Reel Size
Tape Width
Quantity
330 mm
24 mm
1000 pc/reel
Freescale Semiconductor, Inc...
Tape and Reel
Motorola Sensor Device Data
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Freescale Semiconductor, Inc.
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Integrated Silicon Pressure Sensor
On-Chip Signal Conditioned,
MPX4080D
Temperature Compensated
and Calibrated
The MPX4080D series piezoresistive transducer is a state–of–the–art monolithic
silicon pressure sensor designed for a wide range of applications, but particularly those
employing a microcontroller or microprocessor with A/D inputs. This patented, single
element transducer combines advanced micromachining techniques, thin–film metallization, and bipolar processing to provide an accurate, high level analog output signal that is
proportional to the applied pressure.
INTEGRATED PRESSURE
SENSOR
0 to 80 kPa (0 to 11.6 psi)
0.58 to 4.9 Volts Output
Freescale Semiconductor, Inc...
Features
• 3.0% Maximum Error over 0° to 85°C
• Ideally suited for Microprocessor or Microcontroller–Based Systems
UNIBODY PACKAGE
• Temperature Compensated from –40° to 105°C
• Easy–to–Use, Durable Epoxy Unibody Package
Figure 1 shows a block diagram of the internal
circuitry integrated on the pressure sensor chip.
MPX4080D
CASE 867
VS
NOTE: Pin 1 is the notched pin.
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
PIN NUMBER
Vout
PINS 4, 5 AND 6 ARE NO CONNECTS
GND
1
Vout
4
N/C
2
Gnd
5
N/C
3
VS
6
N/C
NOTE: Pins 4, 5, and 6 are internal
device connections. Do not connect
to external circuitry or ground. Pin 1
is noted by the notch in the lead.
Figure 1. Fully Integrated Pressure Sensor Schematic
REV 1
3–54
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Freescale Semiconductor, Inc.
MPX4080D
MAXIMUM RATINGS(NOTE)
Parametrics
Maximum Pressure
(P1 > P2)
(P2 > P1)
Storage Temperature
Symbol
Value
Unit
Pmax
400
400
kPa
Tstg
– 40° to +125°
°C
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 5.1 Vdc, TA = 25°C unless otherwise noted, P1 > P2. Decoupling circuit shown in Figure 4
required to meet electrical specifications.)
Freescale Semiconductor, Inc...
Characteristic
Symbol
Min
Max
Unit
—
80
kPa
5.1
5.35
Vdc
7.0
10
mAdc
0.478
0.575
0.672
Vdc
Pressure Range(1)
POP
0
Supply Voltage(2)
VS
4.85
Supply Current
Io
—
Voff
Minimum Pressure Offset(3)
@ VS = 5.1 Volts
(0 to 85°C)
Typ
Full Scale Output(4)
@ VS = 5.1 Volts
(0 to 85°C)
VFSO
4.772
4.900
5.020
Vdc
Full Scale Span(5)
@ VS = 5.1 Volts
(0 to 85°C)
VFSS
—
4.325
—
Vdc
—
—
—
"3.0
%VFSS
V/P
—
54
—
mV/kPa
Accuracy(6)
Sensitivity
NOTES:
1. 1.0kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range.
3. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
4. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
5. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
6. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from
minimum or maximum rated pressure at 25°C.
• TcSpan:
Output deviation over the temperature range of 0° to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum pressure applied, over the temperature range of 0° to 85°C, relative
to 25°C.
• Variation from Nominal: The variation from nominal values, for Offset or Full Scale Span, as a percent of VFSS at 25°C.
Motorola Sensor Device Data
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Freescale Semiconductor, Inc.
MPX4080D
ON–CHIP TEMPERATURE COMPENSATION, CALIBRATION and SIGNAL CONDITIONING
5
VS = 5.1 Vdc
TA = 25°C
MPX4080
4
MAX
TYP
SPAN RANGE (TYP)
3.5
3
2.5
MIN
2
1.5
OUTPUT RANGE (TYP)
4.5
OUTPUT (V)
Figure 2 shows the sensor output signal relative to
differential pressure input. Typical, minimum, and
maximum output curves are shown for operation over a
temperature range of 0° to 85°C using the decoupling
circuit shown in Figure 4. The output will saturate outside of the specified pressure range.
1
OFFSET
(TYP)
PRESSURE (kPa)
Freescale Semiconductor, Inc...
80
70
60
50
40
30
20
10
0
0
0.5
Figure 2. Output versus Pressure Differential
FLUORO SILICONE
GEL DIE COAT
STAINLESS STEEL
METAL COVER
EPOXY PLASTIC
CASE
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
DIE
WIRE BOND
DIE
BOND
LEAD FRAME
DIFFERENTIAL/GAUGE ELEMENT
Figure 3. Cross–Sectional Diagrams
(Not to Scale)
than dry air, may have adverse effects on sensor performance and long–term reliability. Contact the factory for
information regarding media compatibility in your application.
Figure 4 shows the recommended decoupling circuit for interfacing the output of the integrated sensor to the A/D input
of a microprocessor or microcontroller. Proper decoupling of
the power supply is recommended.
Figure 3 illustrates the differential sensing chip in the basic
chip carrier (Case 867). A fluorosilicone gel isolates the die
surface and wire bonds from the environment, while allowing
the pressure signal to be transmitted to the sensor diaphragm.
The MPX4080D pressure sensor operating characteristics, internal reliability, and qualification tests are based
on use of dry air as the pressure media. Media, other
+5 V
Vout
OUTPUT
Vs
IPS
m
1.0 F
m
0.01 F
GND
470 pF
Figure 4. Recommended power supply decoupling
and output filtering.
For additional output filtering, please refer to
Application Note AN1646.
3–56
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MPX4080D
Transfer Function (MPX4080D)
Nominal Transfer Value: Vout = VS (P x 0.01059 + 0.11280)
+/– (Pressure Error x Temp. Mult. x 0.01059 x VS)
VS = 5.1 V ±0.25V P kPa
Temperature Error Multiplier
Break Points
MPX4080D
4.0
3.0
Temp
Multiplier
– 40
0 to 85
+105
3
1
2
1.0
0.0
–40
–20
0
20
40
60
80
100
120
130
140
Temperature in °C
NOTE: The Temperature Multiplier is a linear response from 0° to –40°C and from 85° to 105°C.
Pressure Error Band
Error Limits for Pressure
3.0
2.0
Error (kPa)
Freescale Semiconductor, Inc...
2.0
1.0
0.0
0
20
40
60
80
100
120
Pressure in kPa
–1.0
–2.0
MPX4080D
–3.0
Motorola Sensor Device Data
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Pressure
Error (max)
0 to 6 kPa
0 to 60 kPa
60 to 80 kPa
± 1.8 kPa
± 1.5 kPa
± 2.3 kPa
3–57
Freescale Semiconductor, Inc.
MPX4080D
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing fluoro silicone gel
which protects the die from harsh media. The Motorola pres-
sure sensor is designed to operate with positive differential
pressure applied, P1 > P2.
The Pressure (P1) side is identified by the stainless steel
cap.
ORDERING INFORMATION:
The MPX4080D is available only in the unibody package.
Device Order No.
No
Differential
Case No
No.
Device Marking
867
MPX4080D
Freescale Semiconductor, Inc...
MPX4080D
Device Type
3–58
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Freescale Semiconductor, Inc.
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
MPX4100
SERIES
Integrated Silicon Pressure Sensor
Manifold Absolute Pressure Sensor
On-Chip Signal Conditioned,
Temperature Compensated
Freescale Semiconductor, Inc...
and Calibrated
INTEGRATED
PRESSURE SENSOR
20 to 105 kPa (2.9 to 15.2 psi)
0.3 to 4.9 V Output
The Motorola MPX4100 series Manifold Absolute Pressure (MAP) sensor for engine
control is designed to sense absolute air pressure within the intake manifold. This
measurement can be used to compute the amount of fuel required for each cylinder. The
small form factor and high reliability of on–chip integration makes the Motorola MAP
sensor a logical and economical choice for automotive system designers.
Features
• 1.8% Maximum Error Over 0° to 85°C
• Specifically Designed for Intake Manifold Absolute Pressure Sensing in Engine
Control Systems
• Ideally Suited for Microprocessor Interfacing
BASIC CHIP CARRIER
ELEMENT
CASE 867–08, STYLE 1
• Temperature Compensated Over – 40°C to +125°C
• Durable Epoxy Unibody Element
• Ideal for Non–Automotive Applications
Application Examples
PIN NUMBER
• Manifold Sensing for Automotive Systems
1
Vout
4
N/C
2
Gnd
5
N/C
3
VS
6
N/C
NOTE: Pins 4, 5, and 6 are internal
device connections. Do not connect
to external circuitry or ground. Pin 1
is noted by the notch in the Lead.
VS
3
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
2
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
1
Vout
The MPX4100 series piezoresistive transducer is a state–
of–the–art, monolithic, signal conditioned, silicon pressure
sensor. This sensor combines advanced micromachining
techniques, thin film metallization, and bipolar semiconductor
processing to provide an accurate, high level analog output
signal that is proportional to applied pressure.
Figure 1 shows a block diagram of the internal circuitry
integrated on a pressure sensor chip.
PINS 4, 5 AND 6 ARE NO CONNECTS
GND
Figure 1. Fully Integrated Pressure Sensor Schematic
REV 5
Motorola Sensor Device Data
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MPX4100 SERIES
MAXIMUM RATINGS(1)
Symbol
Value
Unit
Overpressure(2) (P1 > P2)
Parametric
Pmax
400
kPa
Burst Pressure(2) (P1 > P2)
Pburst
1000
kPa
Tstg
– 40 to +125
°C
TA
– 40 to +125
°C
Storage Temperature
Operating Temperature
1. TC = 25°C unless otherwise noted.
2. Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 5.1 Vdc, TA = 25°C unless otherwise noted, P1 > P2)
Characteristic
Symbol
Min
Typ
Max
Unit
Pressure Range(1)
POP
20
—
105
kPa
Supply Voltage(1)
VS
4.85
5.1
5.35
Vdc
Freescale Semiconductor, Inc...
Supply Current
Io
—
7.0
10
mAdc
Minimum Pressure Offset(3)
@ VS = 5.1 Volts
(0 to 85°C)
Voff
0.225
0.306
0.388
Vdc
Full Scale Output(4)
@ VS = 5.1 Volts
(0 to 85°C)
VFSO
4.815
4.897
4.978
Vdc
Full Scale Span(5)
@ VS = 5.1 Volts
(0 to 85°C)
VFSS
—
4.59
—
Vdc
Accuracy(6)
(0 to 85°C)
—
—
—
±1.8
%VFSS
mV/kPa
Sensitivity
V/P
—
54
—
Response Time(7)
tR
—
1.0
—
ms
Output Source Current at Full Scale Output
Io+
—
0.1
—
mAdc
Warm–Up Time(8)
—
—
20
—
ms
Offset Stability(9)
—
—
± 0.5
—
%VFSS
Symbol
Min
Typ
Max
Unit
Weight, Basic Element (Case 867)
—
—
4.0
—
Grams
Common Mode Line Pressure(10)
—
—
—
690
kPa
Decoupling circuit shown in Figure 3 required to meet electrical specifications.
MECHANICAL CHARACTERISTICS
Characteristic
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range.
3. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
4. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
5. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
6. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation over the temperature range of 0 to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative to
25°C.
• Variation from Nominal: The variation from nominal values, for Offset or Full Scale Span, as a percent of VFSS, at 25°C.
7. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
8. Warm–up is defined as the time required for the product to meet the specified output voltage after the Pressure has been stabilized.
9. Offset stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
10. Common mode pressures beyond specified may result in leakage at the case–to–lead interface.
3–60
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
FLUORO SILICONE
GEL DIE COAT
DIE
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
P1
WIRE BOND
LEAD
FRAME
+5 V
STAINLESS
STEEL CAP
EPOXY
PLASTIC
CASE
m
1.0 F
3
1
IPS
2
OUTPUT
m
0.01 F
DIE
BOND
ABSOLUTE ELEMENT
P2
MPX4100 SERIES
SEALED VACUUM REFERENCE
Figure 3. Recommended Power Supply Decoupling.
For output filtering recommendations, please refer
to Application Note AN1646.
Figure 2 illustrates an absolute sensing chip in the basic
chip carrier (Case 867). A fluorosilicone gel isolates the
die surface and wire bonds from the environment, while
allowing the pressure signal to be transmitted to the sensor diaphragm. The MPX4100A series pressure sensor
operating characteristics, and internal reliability and qualification tests are based on use of dry air as the pressure
media. Media, other than dry air, may have adverse effects
on sensor performance and long–term reliability. Contact
the factory for information regarding media compatibility in
your application.
Figure 4 shows the sensor output signal relative to pressure input. Typical, minimum, and maximum output curves
are shown for operation over a temperature range of 0° to
85°C. (The output will saturate outside of the specified pressure range.)
5.0
4.5
4.0
OUTPUT (Volts)
3.5
3.0
TRANSFER FUNCTION:
Vout = Vs* (.01059*P–.152) ± Error
VS = 5.1 Vdc
TEMP = 0 to 85°C
20 kPa TO 105 kPa
MPX4100A
MAX
TYP
2.5
2.0
1.5
1.0
MIN
0.5
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
Freescale Semiconductor, Inc...
Figure 2. Cross Sectional Diagram
(Not to Scale)
Pressure (ref: to sealed vacuum) in kPa
Figure 4. Output versus Absolute Pressure
Motorola Sensor Device Data
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Information On This Product,
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3–61
Freescale Semiconductor, Inc.
MPX4100 SERIES
Transfer Function (MPX4100A)
Nominal Transfer Value: Vout = VS (P x 0.01059 – 0.1518)
+/– (Pressure Error x Temp. Factor x 0.01059 x VS)
VS = 5.1 V ± 0.25 Vdc
Temperature Error Band
MPX4100A Series
4.0
Temperature
Error
Factor
2.0
Temp
Multiplier
– 40
0 to 85
+125
3
1
3
1.0
0.0
–40
–20
0
20
40
60
80
100
120
140
Temperature in C°
Pressure Error Band
Error Limits for Pressure
3.0
2.0
Pressure Error (kPa)
Freescale Semiconductor, Inc...
3.0
1.0
0.0
20
40
60
80
100
120
Pressure (in kPa)
–1.0
– 2.0
– 3.0
3–62
Pressure
Error (Max)
20 to 105 (kPa)
± 1.5 (kPa)
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPX4100 SERIES
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing fluorosilicone gel
which protects the die from harsh media. The Motorola MPX
Freescale Semiconductor, Inc...
Part Number
pressure sensor is designed to operate with positive differential pressure applied, P1 > P2.
The Pressure (P1) side may be identified by using the table
below:
Pressure (P1)
Side Identifier
Case Type
MPX4100A
867–08
Stainless Steel Cap
MPX4100AP
867B–04
Side with Port Marking
MPX4100AS
867E–03
Side with Port Attached
MPX4100ASX
867F–03
Side with Port Attached
ORDERING INFORMATION
The MPX4100A series MAP silicon pressure sensors are available in the Basic Element, or with pressure port fittings that
provide mounting ease and barbed hose connections.
MPX Series
Device Type
Options
Case Type
Order Number
Device Marking
Basic Element
Absolute, Element Only
867–08
MPX4100A
MPX4100A
Ported Elements
Absolute, Ported
867B–04
MPX4100AP
MPX4100AP
Absolute, Stove Pipe Port
867E–03
MPX4100AS
MPX4100A
Absolute, Axial Port
867F–03
MPX4100ASX
MPX4100A
Motorola Sensor Device Data
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3–63
Freescale Semiconductor, Inc.
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Integrated Silicon Pressure Sensor
MPX4100A
for Manifold Absolute Pressure
MPXA4100A
Applications
SERIES
On-Chip Signal Conditioned,
Temperature Compensated
Freescale Semiconductor, Inc...
and Calibrated
INTEGRATED
PRESSURE SENSOR
15 to 115 kPa (2.2 to 16.7 psi)
0.2 to 4.8 Volts Output
The Motorola MPX4100A/MPXA4100A series Manifold Absolute Pressure (MAP)
sensor for engine control is designed to sense absolute air pressure within the intake
manifold. This measurement can be used to compute the amount of fuel required for each
cylinder. The small form factor and high reliability of on–chip integration makes the
Motorola MAP sensor a logical and economical choice for automotive system designers.
The MPX4100A/MPXA4100A series piezoresistive transducer is a state–of–the–art,
monolithic, signal conditioned, silicon pressure sensor. This sensor combines advanced
micromachining techniques, thin film metallization, and bipolar semiconductor processing
to provide an accurate, high level analog output signal that is proportional to applied
pressure.
Figure 1 shows a block diagram of the internal circuitry integrated on a pressure
sensor chip.
UNIBODY PACKAGE
MPX4100A
CASE 867
Features
• 1.8% Maximum Error Over 0° to 85°C
• Specifically Designed for Intake Manifold Absolute
Pressure Sensing in Engine Control Systems
• Temperature Compensated Over – 40°C to +125°C
• Durable Epoxy Unibody Element or Thermoplastic
(PPS) Surface Mount Package
SMALL OUTLINE PACKAGE
Application Examples
• Manifold Sensing for Automotive Systems
• Ideally suited for Microprocessor or Microcontroller–
Based Systems
MPX4100AP
CASE 867B
MPXA4100A6U
CASE 482
• Also Ideal for Non–Automotive Applications
VS
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
MPXA4100AC6U
CASE 482A
Vout
MPX4100AS
CASE 867E
PIN NUMBER
PINS 1, 5, 6, 7 AND 8 ARE NO CONNECTS
FOR SMALL OUTLINE PACKAGE DEVICE
GND
PINS 4, 5 AND 6 ARE NO CONNECTS FOR
UNIBODY DEVICE
Figure 1. Fully Integrated Pressure Sensor
Schematic
REV 5
3–64
PIN NUMBER
1
N/C
5
N/C
1
Vout
4
N/C
2
VS
Gnd
6
N/C
2
Gnd
5
N/C
3
7
N/C
3
VS
6
N/C
4
Vout
8
N/C
NOTE: Pins 1, 5, 6, 7, and 8 are
internal device connections. Do not
connect to external circuitry or
ground. Pin 1 is noted by the notch in
the lead.
NOTE: Pins 4, 5, and 6 are internal
device connections. Do not connect
to external circuitry or ground. Pin 1
is noted by the notch in the lead.
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Motorola Sensor Device Data
Freescale Semiconductor,MPX4100A
Inc.
MPXA4100A SERIES
MAXIMUM RATINGS(NOTE)
Parametrics
Maximum Pressure (P1
u P2)
Symbol
Value
Units
Pmax
400
kPa
Tstg
–40° to +125°
°C
TA
–40° to +125°
°C
Storage Temperature
Operating Temperature
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 5.1 Vdc, TA = 25°C unless otherwise noted, P1 > P2. Decoupling circuit shown in Figure 3
required to meet electrical specifications.)
Symbol
Min
Typ
Max
Unit
Pressure Range(1)
POP
20
—
105
kPa
Supply Voltage(2)
VS
4.85
5.1
5.35
Vdc
Supply Current
Io
—
7.0
10
mAdc
Freescale Semiconductor, Inc...
Characteristic
Minimum Pressure Offset(3)
@ VS = 5.1 Volts
(0 to 85°C)
Voff
0.225
0.306
0.388
Vdc
Full Scale Output(4)
@ VS = 5.1 Volts
(0 to 85°C)
VFSO
4.870
4.951
5.032
Vdc
Full Scale Span(5)
@ VS = 5.1 Volts
(0 to 85°C)
VFSS
—
4.59
—
Vdc
Accuracy(6)
(0 to 85°C)
—
—
—
±1.8
%VFSS
Sensitivity
V/P
—
54
—
mV/kPa
Response Time(7)
tR
—
1.0
—
ms
Output Source Current at Full Scale Output
Io+
—
0.1
—
mAdc
Warm–Up Time(8)
—
—
20
—
ms
Offset Stability(9)
—
—
± 0.5
—
%VFSS
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range.
3. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
4. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
5. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
6. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation over the temperature range of 0 to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative to
25°C.
• Variation from Nominal: The variation from nominal values, for Offset or Full Scale Span, as a percent of VFSS, at 25°C.
7. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
8. Warm–up Time is defined as the time required for the product to meet the specified output voltage after the Pressure has been stabilized.
9. Offset Stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
MECHANICAL CHARACTERISTICS
Characteristics
Typ
Unit
Weight, Basic Element (Case 867)
4.0
grams
Weight, Small Outline Package (Case 482)
1.5
grams
Motorola Sensor Device Data
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3–65
Freescale Semiconductor, Inc.
MPX4100A MPXA4100A SERIES
FLUORO SILICONE
GEL DIE COAT
DIE
+5 V
STAINLESS
STEEL CAP
Vout
P1
WIRE BOND
Vs
THERMOPLASTIC
CASE
LEAD
FRAME
IPS
m
1.0 F
ABSOLUTE ELEMENT
OUTPUT
m
0.01 F
GND
470 pF
DIE BOND
SEALED VACUUM REFERENCE
Figure 3. Recommended power supply decoupling
and output filtering.
For additional output filtering, please refer to
Application Note AN1646.
Figure 2 illustrates the absolute sensing chip in the basic
chip carrier (Case 482).
Figure 3 shows the recommended decoupling circuit for
interfacing the output of the integrated sensor to the A/D input of a microprocessor or microcontroller. Proper decoupling of the power supply is recommended.
5.0
4.5
4.0
OUTPUT (Volts)
3.5
3.0
TRANSFER FUNCTION:
Vout = Vs* (.01059*P–.152) ± Error
VS = 5.1 Vdc
TEMP = 0 to 85°C
20 kPa TO 105 kPa
MPX4100A
MAX
TYP
2.5
2.0
1.5
MIN
1.0
0.5
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
Freescale Semiconductor, Inc...
Figure 2. Cross Sectional Diagram SOP
(not to scale)
Pressure (ref: to sealed vacuum) in kPa
Figure 4. Output versus Absolute Pressure
Figure 4 shows the sensor output signal relative to pressure input. Typical, minimum, and maximum output curves
are shown for operation over a temperature range of 0° to
85°C. The output will saturate outside of the specified pressure range.
A fluorosilicone gel isolates the die surface and wire
bonds from the environment, while allowing the pressure
signal to be transmitted to the sensor diaphragm. The
3–66
MPX4100A/MPXA4100A series pressure sensor operating characteristics, and internal reliability and qualification
tests are based on use of dry air as the pressure media.
Media, other than dry air, may have adverse effects on
sensor performance and long–term reliability. Contact the
factory for information regarding media compatibility in
your application.
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor,MPX4100A
Inc.
MPXA4100A SERIES
Transfer Function (MPX4100A, MPXA4100A)
Nominal Transfer Value: Vout = VS (P x 0.01059 – 0.1518)
+/– (Pressure Error x Temp. Factor x 0.01059 x VS)
VS = 5.1 V ± 0.25 Vdc
Temperature Error Band
MPX4100A, MPXA4100A Series
4.0
Temperature
Error
Factor
2.0
Temp
Multiplier
– 40
0 to 85
+125
3
1
3
1.0
0.0
–40
–20
0
20
40
60
80
100
120
140
Temperature in C°
NOTE: The Temperature Multiplier is a linear response from 0°C to –40°C and from 85°C to 125°C.
Pressure Error Band
Error Limits for Pressure
3.0
2.0
Pressure Error (kPa)
Freescale Semiconductor, Inc...
3.0
1.0
0.0
20
40
60
80
100
120
Pressure (in kPa)
–1.0
– 2.0
– 3.0
Motorola Sensor Device Data
Pressure
Error (Max)
20 to 105 (kPa)
± 1.5 (kPa)
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3–67
Freescale Semiconductor, Inc.
MPX4100A MPXA4100A SERIES
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing fluorosilicone gel
which protects the die from harsh media. The Motorola MPX
Part Number
pressure sensor is designed to operate with positive differential pressure applied, P1 > P2.
The Pressure (P1) side may be identified by using the table
below:
Pressure (P1)
Side Identifier
Case Type
MPX4100A
867
Stainless Steel Cap
MPX4100AP
867B
Side with Port Marking
MPX4100AS
867E
Side with Port Attached
MPXA4100A6U/T1
482
Stainless Steel Cap
MPXA4100AC6U
482A
Side with Port Attached
Freescale Semiconductor, Inc...
ORDERING INFORMATION — UNIBODY PACKAGE
MPX Series
Device Type
Options
Case Type
Order Number
Device Marking
Basic Element
Absolute, Element Only
867
MPX4100A
MPX4100A
Ported Elements
Absolute, Ported
867B
MPX4100AP
MPX4100AP
Absolute, Stove Pipe Port
867E
MPX4100AS
MPX4100A
ORDERING INFORMATION — SMALL OUTLINE PACKAGE
Device Type
Options
Case No.
Basic Element
Absolute, Element Only
482
MPXA4100A6U
Rails
MPXA4100A
Absolute, Element Only
482
MPXA4100A6T1
Tape and Reel
MPXA4100A
Absolute, Axial Port
482A
MPXA4100AC6U
Rails
MPXA4100A
Ported Element
3–68
MPX Series Order No.
Packing Options
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Marking
Motorola Sensor Device Data
Freescale Semiconductor,MPX4100A
Inc.
MPXA4100A SERIES
INFORMATION FOR USING THE SMALL OUTLINE PACKAGE (CASE 482)
MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS
Surface mount board layout is a critical portion of the total
design. The footprint for the surface mount packages must
be the correct size to ensure proper solder connection interface between the board and the package. With the correct
footprint, the packages will self align when subjected to a
solder reflow process. It is always recommended to design
boards with a solder mask layer to avoid bridging and shorting between solder pads.
0.100 TYP 8X
2.54
0.660
16.76
Freescale Semiconductor, Inc...
0.060 TYP 8X
1.52
0.300
7.62
0.100 TYP 8X
2.54
inch
mm
SCALE 2:1
Figure 5. SOP Footprint (Case 482)
Motorola Sensor Device Data
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3–69
Freescale Semiconductor, Inc.
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
MPX4101A
Integrated Silicon Pressure Sensor
MPXA4101A
for Manifold Absolute Pressure
MPXH6101A
Applications
SERIES
On-Chip Signal Conditioned,
Temperature Compensated
INTEGRATED
PRESSURE SENSOR
15 to 102 kPa
(2.18 to 14.8 psi)
0.25 to 4.95 V Output
Freescale Semiconductor, Inc...
and Calibrated
The Motorola MPX4101A/MPXA4101A/MPXH6101A series Manifold Absolute
Pressure (MAP) sensor for engine control is designed to sense absolute air pressure
within the intake manifold. This measurement can be used to compute the amount of
fuel required for each cylinder. The small form factor and high reliability of on–chip
integration makes the Motorola MAP sensor a logical and economical choice for
automotive system designers.
The MPX4101A/MPXA4101A/MPXH6101A series piezoresistive transducer is a
state–of–the–art, monolithic, signal conditioned, silicon pressure sensor. This sensor
combines advanced micromachining techniques, thin film metallization, and bipolar
semiconductor processing to provide an accurate, high level analog output signal that is
proportional to applied pressure.
Figure 1 shows a block diagram of the internal circuitry integrated on a pressure
sensor chip.
SMALL OUTLINE
PACKAGE
MPXA4101AC6U
CASE 482A
Features
• 1.72% Maximum Error Over 0° to 85°C
PIN NUMBER
• Specifically Designed for Intake Manifold Absolute
Pressure Sensing in Engine Control Systems
• Temperature Compensated Over – 40°C to +125°C
• Durable Epoxy Unibody Element or Thermoplastic (PPS) Surface Mount Package
Application Examples
1
N/C
5
N/C
2
VS
Gnd
6
N/C
3
7
N/C
4
Vout
8
N/C
NOTE: Pins 1, 5, 6, 7, and 8 are not
device connections. Do not connect
to external circuitry or ground. Pin 1
is noted by the notch in the lead.
• Manifold Sensing for Automotive Systems
• Ideally Suited for Microprocessor or Microcontroller–Based Systems
• Also Ideal for Non–Automotive Applications
SUPER SMALL OUTLINE
PACKAGE
UNIBODY PACKAGE
MPXH6101A6T1
CASE 1317
MPX4101A
CASE 867
VS
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
PINS 1, 5, 6, 7 AND 8 ARE NO CONNECTS
FOR SMALL OUTLINE DEVICE
GND
PINS 4, 5 AND 6 ARE NO CONNECTS FOR
UNIBODY DEVICE
Figure 1. Fully Integrated Pressure Sensor
Schematic
Vout
PIN NUMBER
PIN NUMBER
1
N/C
5
N/C
1
Vout
4
N/C
2
VS
Gnd
6
N/C
2
Gnd
5
N/C
3
7
N/C
3
VS
6
N/C
4
Vout
8
N/C
NOTE: Pins 1, 5, 6, 7, and 8 are
internal device connections. Do not
connect to external circuitry or
ground. Pin 1 is denoted by the
chamfered corner of the package.
NOTE: Pins 4, 5, and 6 are internal
device connections. Do not connect
to external circuitry or ground. Pin 1
is noted by the notch in the lead.
REV 4
3–70
For www.motorola.com/semiconductors
More Information On This Product,
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Motorola Sensor Device Data
Freescale Semiconductor,
Inc.
MPX4101A MPXA4101A
MPXH6101A SERIES
MAXIMUM RATINGS(NOTE)
Parametric
Maximum Pressure (P1 > P2)
Storage Temperature
Symbol
Value
Unit
Pmax
400
kPa
Tstg
– 40 to +125
°C
TA
– 40 to +125
°C
Operating Temperature
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 5.1 Vdc, TA = 25°C unless otherwise noted, P1 > P2. Decoupling circuit shown in Figure 3
required to meet electrical specifications.)
Symbol
Min
Typ
Max
Unit
Pressure Range(1)
POP
15
—
102
kPa
Supply Voltage(2)
VS
4.85
5.1
5.35
Vdc
Supply Current
Io
—
7.0
10
mAdc
Freescale Semiconductor, Inc...
Characteristic
Minimum Pressure Offset(3)
@ VS = 5.1 Volts
(0 to 85°C)
Voff
0.171
0.252
0.333
Vdc
Full Scale Output(4)
@ VS = 5.1 Volts
(0 to 85°C)
VFSO
4.870
4.951
5.032
Vdc
Full Scale Span(5)
@ VS = 5.1 Volts
(0 to 85°C)
VFSS
—
4.7
—
Vdc
Accuracy(6)
(0 to 85°C)
—
—
—
±1.72
%VFSS
Sensitivity
V/P
—
54
—
mV/kPa
Response Time(7)
tR
—
15
—
ms
Output Source Current at Full Scale Output
Io+
—
0.1
—
mAdc
Warm–Up Time(8)
—
—
20
—
ms
Offset Stability(9)
—
—
± 0.5
—
%VFSS
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range.
3. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
4. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
5. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
6. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation over the temperature range of 0 to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative
to 25°C.
• Variation from Nominal: The variation from nominal values, for Offset or Full Scale Span, as a percent of VFSS, at 25°C.
7. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
8. Warm–up Time is defined as the time required for the product to meet the specified output voltage after the Pressure has been stabilized.
9. Offset Stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
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3–71
Freescale
Semiconductor, Inc.
MPX4101A MPXA4101A MPXH6101A
SERIES
DIE
FLUORO SILICONE
GEL DIE COAT
STAINLESS
STEEL CAP
P1
WIRE BOND
THERMOPLASTIC
CASE
LEAD
FRAME
ABSOLUTE ELEMENT
DIE BOND
SEALED VACUUM REFERENCE
Figure 2 illustrates an absolute sensing chip in the super small outline package (Case 1317).
5.0
+5.1 V
4.5
4.0
VS Pin 2
100 nF
MPXH6101A
Vout Pin 4
GND Pin 3
to ADC
47 pF
51 K
OUTPUT (Volts)
3.5
3.0
TRANSFER FUNCTION:
Vout = Vs* (PX0.01059*P–0.10941) ± Error
VS = 5.1 Vdc
TEMP = 0 to 85°C
MAX
20 kPa TO 105 kPa
MPX4101A
TYP
2.5
2.0
1.5
MIN
1.0
0.5
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
Freescale Semiconductor, Inc...
Figure 2. Cross Sectional Diagram SSOP
(not to scale)
Pressure (ref: to sealed vacuum) in kPa
Figure 3. Recommended power supply decoupling
and output filtering.
Figure 4 shows the sensor output signal relative to pressure input. Typical, minimum, and maximum output curves
are shown for operation over a temperature range of 0° to
85°C. The output will saturate outside of the specified pressure range.
A fluorosilicone gel isolates the die surface and wire
bonds from the environment, while allowing the pressure
signal to be transmitted to the sensor diaphragm. The
MPX4101A/MPXA4101A/MPXH6101A series pressure sensor operating characteristics, and internal reliability and qual-
3–72
Figure 4. Output versus Absolute Pressure
ification tests are based on use of dry air as the pressure
media. Media, other than dry air, may have adverse effects
on sensor performance and long–term reliability. Contact the
factory for information regarding media compatibility in your
application.
Figure 3 shows the recommended decoupling circuit for
interfacing the output of the integrated sensor to the A/D input of a microprocessor or microcontroller. Proper decoupling of the power supply is recommended.
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor,
Inc.
MPX4101A MPXA4101A
MPXH6101A SERIES
Transfer Function (MPX4101A, MPXA4101A, MPXH6101A)
Nominal Transfer Value: Vout = VS (P x 0.01059 – 0.10941)
+/– (Pressure Error x Temp. Factor x 0.01059 x VS)
VS = 5.1 V ± 0.25 Vdc
Temperature Error Band
MPX4101A, MPXA4101A, MPXH6101A Series
4.0
3.0
2.0
Multiplier
– 40
0 to 85
+125
3
1
3
1.0
0.0
–40
–20
0
20
40
60
80
100
120
140
Temperature in °C
NOTE: The Temperature Multiplier is a linear response from 0° to – 40°C and from 85° to 125°C.
Pressure Error Band
Error Limits for Pressure
3.0
Pressure Error (kPa)
Freescale Semiconductor, Inc...
Temperature
Error
Factor
Temp
2.0
1.0
0.0
Pressure (in kPa)
0
15
30
45
60
75
90
105
120
–1.0
– 2.0
– 3.0
Motorola Sensor Device Data
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For More
Information On This Product,
Go to: www.freescale.com
Pressure
Error (Max)
15 to 102 (kPa)
± 1.5 (kPa)
3–73
Freescale
Semiconductor, Inc.
MPX4101A MPXA4101A MPXH6101A
SERIES
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing fluorosilicone gel
which protects the die from harsh media. The Motorola pres-
Part Number
sure sensor is designed to operate with positive differential
pressure applied, P1 > P2.
The Pressure (P1) side may be identified by using the table
below:
Pressure (P1)
Side Identifier
Case Type
MPX4101A
867
Stainless Steel Cap
MPXA4101AC6U
482A
Side with Port Attached
MPXH6101A6U
1317
Stainless Steel Cap
MPXH6101A6T1
1317
Stainless Steel Cap
Freescale Semiconductor, Inc...
ORDERING INFORMATION — UNIBODY PACKAGE
The MPX4101A series MAP silicon pressure sensors are available in the Basic Element, or with pressure port fittings that
provide mounting ease and barbed hose connections.
MPX Series
Device Type
Basic Element
Options
Case Type
Absolute, Element Only
867
Order Number
Device Marking
MPX4101A
MPX4101A
ORDERING INFORMATION — SMALL OUTLINE PACKAGE
Device Type
Ported Element
Options
Case No.
Absolute, Axial Port
482A
MPX Series Order No.
MPXA4101AC6U
Packing Options
Rails
Marking
MPXA4101A
ORDERING INFORMATION — SUPER SMALL OUTLINE PACKAGE
Device Type
Options
Case No.
MPX Series Order No.
Packing Options
Marking
Basic Element
Absolute, Element Only
1317
MPXH6101A6U
Rails
MPXH6101A
Basic Element
Absolute, Element Only
1317
MPXH6101A6T1
Tape and Reel
MPXH6101A
INFORMATION FOR USING THE SMALL OUTLINE PACKAGES
MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS
Surface mount board layout is a critical portion of the total
design. The footprint for the surface mount packages must
be the correct size to ensure proper solder connection interface between the board and the package. With the correct
footprint, the packages will self align when subjected to a
solder reflow process. It is always recommended to design
boards with a solder mask layer to avoid bridging and shorting between solder pads.
0.100 TYP 8X
2.54
0.660
16.76
0.050
1.27
TYP
0.387
9.83
0.150
3.81
0.060 TYP 8X
1.52
0.300
7.62
0.027 TYP 8X
0.69
0.100 TYP 8X
2.54
inch
mm
Figure 5. SOP Footprint (Case 482)
3–74
0.053 TYP 8X
1.35
SCALE 2:1
inch
mm
Figure 6. SSOP Footprint (Case 1317)
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Integrated Silicon Pressure Sensor
for Manifold Absolute Pressure
MPX4105A
SERIES
Applications
On-Chip Signal Conditioned,
Temperature Compensated
INTEGRATED
PRESSURE SENSOR
15 to 105 kPa
(2.2 to 15.2 psi)
0.3 to 4.9 V Output
Freescale Semiconductor, Inc...
and Calibrated
The Motorola MPX4105A series Manifold Absolute Pressure (MAP) sensor for engine
control is designed to sense absolute air pressure within the intake manifold. This
measurement can be used to compute the amount of fuel required for each cylinder.
Motorola’s MAP sensor integrates on–chip, bipolar op amp circuitry and thin film
resistor networks to provide a high output signal and temperature compensation. The
small form factor and high reliability of on–chip integration make the Motorola MAP
sensor a logical and economical choice for the automotive system designer.
The MPX4105A series piezoresistive transducer is a state–of–the–art, monolithic, signal
conditioned, silicon pressure sensor. This sensor combines advanced micromachining
techniques, thin film metallization, and bipolar semiconductor processing to provide an
accurate, high level analog output signal that is proportional to applied pressure.
Figure 1 shows a block diagram of the internal circuitry integrated on a pressure
sensor chip.
UNIBODY PACKAGE
MPX4105A
CASE 867
Features
• 1.8% Maximum Error Over 0° to 85°C
• Specifically Designed for Intake Manifold Absolute
Pressure Sensing in Engine Control Systems
1
Vout
4
N/C
• Temperature Compensated Over – 40 to +125°C
2
Gnd
5
N/C
3
VS
6
N/C
PIN NUMBER
• Durable Epoxy Unibody Element
Application Examples
• Manifold Sensing for Automotive Systems
• Ideally Suited for Microprocessor or Microcontroller–Based Systems
NOTE: Pins 4, 5, and 6 are internal
device connections. Do not connect
to external circuitry or ground. Pin 1
is noted by the notch in the lead.
• Also Ideal for Non–Automotive Applications
VS
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
GND
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
Vout
PINS 4, 5 AND 6 ARE NO CONNECTS FOR
UNIBODY DEVICE
Figure 1. Fully Integrated Pressure Sensor Schematic
REV 4
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–75
MPX4105A SERIES
Freescale Semiconductor, Inc.
MAXIMUM RATINGS(NOTE)
Parametrics
Maximum Pressure (P1
u P2)
Symbol
Value
Units
Pmax
400
kPa
Tstg
–40° to +125°
°C
TA
–40° to +125°
°C
Storage Temperature
Operating Temperature
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 5.1 Vdc, TA = 25°C unless otherwise noted. Decoupling circuit shown in Figure 3 required to
meet specification.)
Symbol
Min
Typ
Max
Unit
POP
15
—
105
kPa
Supply Voltage(1)
VS
4.85
5.1
5.35
Vdc
Supply Current
Io
—
7.0
10
mAdc
Characteristic
Freescale Semiconductor, Inc...
Pressure Range
Minimum Pressure Offset(2)
(0 to 85°C)
Voff
0.184
0.306
0.428
Vdc
Full Scale Output(3)
(0 to 85°C)
VFSO
4.804
4.896
4.988
Vdc
Full Scale Span(4)
(0 to 85°C)
VFSS
—
4.590
—
Vdc
Accuracy(5)
(0 to 85°C)
—
—
—
±1.8
%VFSS
∆V/∆P
—
51
—
mV/kPa
Response Time(6)
tR
—
1.0
—
ms
Output Source Current at Full Scale Output
Io+
—
0.1
—
mAdc
Warm–up Time(7)
—
—
15
—
ms
Offset Stability(8)
—
—
± 0.65
—
%VFSS
Sensitivity
NOTES:
1. Device is ratiometric within this specified excitation range.
2. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
3. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
4. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
5. Accuracy is the deviation in actual output from nominal output over the entire pressure range and temperature range as a percent of span
at 25°C due to all sources of error including the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with minimum specified
pressure applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from
minimum or maximum rated pressure at 25°C.
• TcSpan:
Span deviation per °C over the temperature range of 0° to 85°C, as a percent of span at 25°C.
• TcOffset:
Output deviation per °C with minimum pressure applied, over the temperature range of 0° to 85°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Warm–up Time is defined as the time required for the product to meet the specified output voltage.
8. Offset Stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
MECHANICAL CHARACTERISTICS
Characteristics
Weight, Basic Element (Case 867)
3–76
Typ
Unit
4.0
grams
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More Information On This Product,
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
FLUORO SILICONE
GEL DIE COAT
+5 V
STAINLESS
STEEL CAP
DIE
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
P1
WIRE BOND
LEAD
FRAME
EPOXY
PLASTIC
CASE
Vout
OUTPUT
Vs
IPS
m
1.0 F
DIE
BOND
ABSOLUTE ELEMENT
P2
SEALED VACUUM REFERENCE
Figure 2. Cross–Sectional Diagram
(not to scale)
m
GND
0.01 F
470 pF
Figure 3. Recommended power supply decoupling
and output filtering.
For additional output filtering, please refer to
Application Note AN1646.
have adverse effects on sensor performance and long–term
reliability. Contact the factory for information regarding media compatibility in your application.
Figure 3 shows the recommended decoupling circuit for interfacing the output of the integrated sensor to the A/D input
of a microprocessor or microcontroller. Proper decoupling of
the power supply is recommended.
Figure 2 illustrates an absolute sensing chip in the basic
chip carrier (Case 867).
A fluorosilicone gel isolates the die surface and wire
bonds from the environment, while allowing the pressure
signal to be transmitted to the sensor diaphragm. The
MPX4105A series pressure sensor operating characteristics,
internal reliability and qualification tests are based on use of
dry air as the pressure media. Media other than dry air may
5.0
4.5
4.0
OUTPUT (Volts)
3.5
3.0
TRANSFER FUNCTION:
Vout = Vs* (0.01*P–0.09) ± Error
VS = 5.1 Vdc
TEMP = 0 to 85°C
15 kPA TO 105 kPA
MPX4105A
MAX
TYP
2.5
2.0
1.5
MIN
1.0
0.5
0
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
Freescale Semiconductor, Inc...
MPX4105A SERIES
Pressure (ref: to sealed vacuum) in kPa
Figure 4. Output versus Absolute Pressure
Figure 4 shows the sensor output signal relative to pressure input. Typical minimum and maximum output curves
are shown for operation over a temperature range of 0° to
Motorola Sensor Device Data
85°C. The output will saturate outside of the specified
pressure range.
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Information On This Product,
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3–77
Freescale Semiconductor, Inc.
MPX4105A SERIES
Transfer Function (MPX4105A)
Nominal Transfer Value: Vout = VS (P x 0.01 – 0.09)
+/– (Pressure Error x Temp. Factor x 0.01 x VS)
VS = 5.1 V ± 0.25 Vdc
Temperature Error Band
MPX4105A Series
4.0
Break Points
3.0
Temperature
Error
Factor
2.0
Temp
Multiplier
– 40
– 20
0 to 85
125
3.0
1.5
1.0
2.5
0.0
–40
–20
0
20
40
60
80
100
120
140
Temperature in C°
NOTE: The Temperature Multiplier is a linear response from –40°C to –20°C, –20°C to 0°C, and from 85°C to 125°C
Pressure Error Band
Error Limits for Pressure
3.0
2.0
Pressure Error (kPa)
Freescale Semiconductor, Inc...
1.0
1.0
0.0
20
40
60
80
100
120
Pressure (in kPa)
–1.0
– 2.0
– 3.0
Pressure
Error (Max)
40 to 94 (kPa)
15 (kPa)
105 (kPa)
± 1.5 (kPa)
± 2.4 (kPa)
± 1.8 (kPa)
ORDERING INFORMATION — UNIBODY PACKAGE
Device Type
Basic Element
3–78
Options
Absolute Element
Absolute,
Case No
No.
867
MPX Series Order No
No.
MPX4105A
For www.motorola.com/semiconductors
More Information On This Product,
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Marking
MPX4105A
Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
Integrated Silicon Pressure Sensor
for Manifold Absolute Pressure,
Altimeter or Barometer Applications
MPX4115A
MPXA4115A
SERIES
On-Chip Signal Conditioned,
Temperature Compensated
Freescale Semiconductor, Inc...
and Calibrated
Motorola’s MPX4115A/MPXA4115A series sensor integrates on–chip, bipolar op amp
circuitry and thin film resistor networks to provide a high output signal and temperature
compensation. The small form factor and high reliability of on–chip integration make the
Motorola pressure sensor a logical and economical choice for the system designer.
The MPX4115A/MPXA4115A series piezoresistive transducer is a state–of–the–art,
monolithic, signal conditioned, silicon pressure sensor. This sensor combines advanced
micromachining techniques, thin film metallization, and bipolar semiconductor processing to
provide an accurate, high level analog output signal that is proportional to applied pressure.
Figure 1 shows a block diagram of the internal circuitry integrated on a pressure
sensor chip.
INTEGRATED
PRESSURE SENSOR
15 to 115 kPa (2.2 to 16.7 psi)
0.2 to 4.8 Volts Output
UNIBODY PACKAGE
Features
• 1.5% Maximum Error over 0° to 85°C
MPX4115A
CASE 867
• Ideally suited for Microprocessor or Microcontroller–
Based Systems
• Temperature Compensated from – 40° to +125°C
• Durable Epoxy Unibody Element or Thermoplastic
(PPS) Surface Mount Package
Application Examples
SMALL OUTLINE PACKAGE
• Aviation Altimeters
• Industrial Controls
• Engine Control
• Weather Stations and Weather Reporting Devices
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
Vout
MPXA4115AC6U
CASE 482A
PINS 1, 5, 6, 7 AND 8 ARE NO CONNECTS
FOR SMALL OUTLINE PACKAGE DEVICE
GND
PINS 4, 5 AND 6 ARE NO CONNECTS FOR
UNIBODY DEVICE
Figure 1. Fully Integrated Pressure Sensor
Schematic
REV 4
Motorola Sensor Device Data
MPX4115AP
CASE 867B
MPXA4115A6U
CASE 482
VS
MPX4115AS
CASE 867E
PIN NUMBER
PIN NUMBER
1
N/C
5
N/C
1
Vout
4
N/C
2
VS
Gnd
6
N/C
2
Gnd
5
N/C
3
7
N/C
3
VS
6
N/C
4
Vout
8
N/C
NOTE: Pins 1, 5, 6, 7, and 8 are
internal device connections. Do not
connect to external circuitry or
ground. Pin 1 is noted by the notch in
the lead.
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For More
Information On This Product,
Go to: www.freescale.com
NOTE: Pins 4, 5, and 6 are internal
device connections. Do not connect
to external circuitry or ground. Pin 1
is noted by the notch in the lead.
3–79
Freescale Semiconductor, Inc.
MPX4115A MPXA4115A SERIES
MAXIMUM RATINGS(NOTE)
Parametrics
Maximum Pressure (P1
u P2)
Symbol
Value
Units
Pmax
400
kPa
Tstg
–40° to +125°
°C
TA
–40° to +125°
°C
Storage Temperature
Operating Temperature
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 5.1 Vdc, TA = 25°C unless otherwise noted, P1
required to meet Electrical Specifications.)
Characteristic
Symbol
Min
Typ
Max
Unit
POP
15
—
115
kPa
Supply Voltage(1)
VS
4.85
5.1
5.35
Vdc
Supply Current
Io
—
7.0
10
mAdc
Pressure Range
Freescale Semiconductor, Inc...
u P2. Decoupling circuit shown in Figure 3
Minimum Pressure Offset(2)
@ VS = 5.1 Volts
(0 to 85°C)
Voff
0.135
0.204
0.273
Vdc
Full Scale Output(3)
@ VS = 5.1 Volts
(0 to 85°C)
VFSO
4.725
4.794
4.863
Vdc
Full Scale Span(4)
@ VS = 5.1 Volts
(0 to 85°C)
VFSS
4.521
4.590
4.659
Vdc
Accuracy(5)
(0 to 85°C)
—
—
—
±1.5
%VFSS
Sensitivity
V/P
—
45.9
—
mV/kPa
Response Time(6)
tR
—
1.0
—
ms
Output Source Current at Full Scale Output
Io+
—
0.1
—
mAdc
Warm–Up Time(7)
—
—
20
—
ms
Offset Stability(8)
—
—
± 0.5
—
%VFSS
NOTES:
1. Device is ratiometric within this specified excitation range.
2. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
3. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
4. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
5. Accuracy is the deviation in actual output from nominal output over the entire pressure range and temperature range as a percent of span
at 25°C due to all sources of error including the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential
pressure applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from
minimum or maximum rated pressure at 25°C.
• TcSpan:
Output deviation over the temperature range of 0° to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum pressure applied, over the temperature range of 0° to 85°C, relative
to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Warm–up Time is defined as the time required for the product to meet the specified output voltage after the pressure has been stabilized.
8. Offset Stability is the product’s output deviation when subjected to 1000 cycles of Pulsed Pressure, Temperature Cycling with Bias Test.
MECHANICAL CHARACTERISTICS
Characteristics
Typ
Unit
Weight, Basic Element (Case 867)
4.0
grams
Weight, Small Outline Package (Case 482)
1.5
grams
3–80
For www.motorola.com/semiconductors
More Information On This Product,
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Motorola Sensor Device Data
Freescale Semiconductor,MPX4115A
Inc.
MPXA4115A SERIES
FLUORO SILICONE
GEL DIE COAT
+5 V
DIE
STAINLESS
STEEL CAP
Vout
P1
WIRE BOND
Vs
THERMOPLASTIC
CASE
LEAD
FRAME
IPS
m
1.0 F
ABSOLUTE ELEMENT
OUTPUT
m
GND
0.01 F
470 pF
DIE BOND
SEALED VACUUM REFERENCE
Figure 3. Recommended power supply decoupling
and output filtering.
For additional output filtering, please refer to
Application Note AN1646.
Figure 2 illustrates the absolute sensing chip in the basic
chip carrier (Case 482).
Figure 3 shows the recommended decoupling circuit for
interfacing the output of the integrated sensor to the A/D input of a microprocessor or microcontroller. Proper decoupling of the power supply is recommended.
5.0
4.5
4.0
OUTPUT (Volts)
3.5
MAX
TRANSFER FUNCTION:
Vout = Vs* (.009*P–.095) ± Error
VS = 5.1 Vdc
TEMP = 0 to 85°C
TYP
3.0
2.5
2.0
1.5
MIN
1.0
0.5
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
115
120
Freescale Semiconductor, Inc...
Figure 2. Cross Sectional Diagram SOP
(not to scale)
Pressure (ref: to sealed vacuum) in kPa
Figure 4. Output versus Absolute Pressure
Figure 4 shows the sensor output signal relative to pressure input. Typical minimum and maximum output curves
are shown for operation over 0 to 85°C temperature range.
The output will saturate outside of the rated pressure range.
A fluorosilicone gel isolates the die surface and wire
bonds from the environment, while allowing the pressure
signal to be transmitted to the silicon diaphragm. The
Motorola Sensor Device Data
MPX4115A/MPXA4115A series pressure sensor operating
characteristics, internal reliability and qualification tests are
based on use of dry air as the pressure media. Media other
than dry air may have adverse effects on sensor performance and long–term reliability. Contact the factory for
information regarding media compatibility in your application.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–81
Freescale Semiconductor, Inc.
MPX4115A MPXA4115A SERIES
Transfer Function (MPX4115A, MPXA4115A)
Nominal Transfer Value: Vout = VS x (0.009 x P – 0.095)
± (Pressure Error x Temp. Factor x 0.009 x VS)
VS = 5.1 ± 0.25 Vdc
Temperature Error Band
MPX4115A, MPXA4115A Series
4.0
Break Points
3.0
Temperature
Error
Factor
2.0
Temp
Multiplier
– 40
0 to 85
125
3
1
3
1.0
–40
–20
0
20
40
60
80
100
120
140
Temperature in C°
NOTE: The Temperature Multiplier is a linear response from 0°C to –40°C and from 85°C to 125°C
Pressure Error Band
Error Limits for Pressure
3.0
2.0
Pressure Error (kPa)
Freescale Semiconductor, Inc...
0.0
1.0
0.0
20
40
60
80
100
Pressure (in kPa)
120
–1.0
– 2.0
– 3.0
Pressure
Error (Max)
15 to 115 (kPa)
± 1.5 (kPa)
ORDERING INFORMATION — UNIBODY PACKAGE
Device Type
Options
Case No.
MPX Series Order No.
Marking
Basic Element
Absolute, Element Only
867
MPX4115A
MPX4115A
Ported Elements
Absolute, Ported
867B
MPX4115AP
MPX4115AP
Absolute, Stove Pipe Port
867E
MPX4115AS
MPX4115A
ORDERING INFORMATION — SMALL OUTLINE PACKAGE
Device Type
Options
Case No.
Basic Element
Absolute, Element Only
482
MPXA4115A6U
Rails
MPXA4115A
Absolute, Element Only
482
MPXA4115A6T1
Tape and Reel
MPXA4115A
Absolute, Axial Port
482A
MPXA4115AC6U
Rails
MPXA4115A
Absolute, Axial Port
482A
MPXA4115AC6T1
Tape and Reel
MPXA4115A
Ported Element
3–82
MPX Series Order No.
Packing Options
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Marking
Motorola Sensor Device Data
Freescale Semiconductor,MPX4115A
Inc.
MPXA4115A SERIES
INFORMATION FOR USING THE SMALL OUTLINE PACKAGE (CASE 482)
MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS
Surface mount board layout is a critical portion of the total
design. The footprint for the surface mount packages must
be the correct size to ensure proper solder connection interface between the board and the package. With the correct
fottprint, the packages will self–align when subjected to a
solder reflow process. It is always recommended to design
boards with a solder mask layer to avoid bridging and shorting between solder pads.
0.100 TYP 8X
2.54
0.660
16.76
Freescale Semiconductor, Inc...
0.060 TYP 8X
1.52
0.300
7.62
0.100 TYP 8X
2.54
inch
mm
SCALE 2:1
Figure 5. SOP Footprint (Case 482)
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
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3–83
Freescale Semiconductor, Inc.
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Integrated Silicon Pressure Sensor
MPX4200A
for Manifold Absolute Pressure
SERIES
Applications
On-Chip Signal Conditioned,
Temperature Compensated
Freescale Semiconductor, Inc...
and Calibrated
The Motorola MPX4200A series Manifold Absolute Pressure (MAP) sensor for turbo
boost engine control is designed to sense absolute air pressure within the intake
manifold. This measurement can be used to compute the amount of fuel required for
each cylinder.
The MPX4200A series sensor integrates on–chip, bipolar op amp circuitry and thin film
resistor networks to provide a high level analog output signal and temperature
compensation. The small form factor and reliability of on–chip integration make the
Motorola MAP sensor a logical and economical choice for automotive system designers.
INTEGRATED
PRESSURE SENSOR
20 to 200 kPa (2.9 to 29 psi)
0.3 to 4.9 V OUTPUT
Features
• Specifically Designed for Intake Manifold Absolute Pressure Sensing in Engine
Control Systems
MPX4200A
CASE 867
• Patented Silicon Shear Stress Strain Gauge
• Temperature Compensated Over – 40° to +125°C
• Offers Reduction in Weight and Volume Compared to Existing Hybrid Modules
PIN NUMBER
• Durable Epoxy Unibody Element
1
Vout
4
N/C
Application Examples
2
Gnd
5
N/C
• Manifold Sensing for Automotive Systems
3
VS
6
N/C
• Ideally suited for Microprocessor or Microcontroller–Based Systems
• Also ideal for Non–Automotive Applications
NOTE: Pins 4, 5, and 6 are internal
device connections. Do not connect
to external circuitry or ground. Pin 1
is noted by the notch in the lead.
VS
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
Vout
PINS 4, 5 AND 6 ARE NO CONNECTS
GND
Figure 1. Fully Integrated Pressure Sensor Schematic
Rev 1
3–84
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPX4200A SERIES
MAXIMUM RATINGS(NOTE)
Parametrics
Maximum Pressure (P1 > P2)
Storage Temperature
Operating Temperature
Symbol
Value
Unit
Pmax
800
kPa
Tstg
– 40 to +125
°C
TA
– 40 to +125
°C
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 5.1 Vdc, TA = 25°C unless otherwise noted, P1 > P2. Decoupling circuit shown in Figure 3
required to meet electrical specifications.)
Freescale Semiconductor, Inc...
Characteristic
Symbol
Min
Typ
Max
Unit
Pressure Range(1)
POP
20
—
200
kPa
Supply Voltage(2)
VS
4.85
5.1
5.35
Vdc
Supply Current
Io
—
7.0
10
mAdc
Minimum Pressure Offset(3)
@ VS = 5.1 Volts
(0 to 85°C)
Voff
0.199
0.306
0.413
Vdc
Full Scale Output(4)
@ VS = 5.1 Volts
(0 to 85°C)
VFSO
4.725
4.896
4.978
Vdc
Full Scale Span(5)
@ VS = 5.1 Volts
(0 to 85°C)
VFSS
—
4.590
—
Vdc
Accuracy(6)
(0 to 85°C)
—
—
—
±1.5
%VFSS
Sensitivity
V/P
—
25.5
—
mV/kPa
Response Time(7)
tR
—
1.0
—
ms
Output Source Current at Full Scale Output
lo+
—
0.1
—
mAdc
Warm–Up Time(8)
—
—
20
—
ms
Offset Stability(9)
—
—
± 0.5
—
%VFSS
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range.
3. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
4. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
5. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
6. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation over the temperature range of 0° to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0° to 85°C, relative
to 25°C.
• Variation from Nominal: The variation from nominal values, for Offset or Full Scale Span, as a percent of VFSS at 25°C.
7. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
8. Warm–up Time is defined as the time required for the product to meet the specified output voltage after the Pressure has been stabilized.
9. Offset Stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
MECHANICAL CHARACTERISTICS
Characteristics
Weight, Basic Element (Case 867)
Motorola Sensor Device Data
Typ
Unit
4.0
grams
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Information On This Product,
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3–85
Freescale Semiconductor, Inc.
MPX4200A SERIES
SILICONE
DIE COAT
+5 V
STAINLESS STEEL
METAL COVER
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
DIE
P1
WIRE BOND
LEAD FRAME
P2
EPOXY
CASE
Vout
OUTPUT
Vs
IPS
m
RTV DIE
BOND
1.0 F
m
GND
0.01 F
470 pF
SEALED VACUUM REFERENCE
Figure 3. Recommended power supply decoupling
and output filtering.
For additional output filtering, please refer to
Application Note AN1646.
Figure 3 shows the recommended decoupling circuit for
interfacing the output of the integrated sensor to the A/D input of a microprocessor or microcontroller. Proper decoupling of the power supply is recommended.
Figure 4 shows the sensor output signal relative to pressure input. Typical minimum and maximum output curves
are shown for operation over temperature range of 0° to
85°C. The output will saturate outside of the specified pressure range.
Figure 2 illustrates the absolute sensing chip in the basic
chip carrier (Case 867). A fluorosilicone gel isolates the
die surface and wire bonds from the environment, while
allowing the pressure signal to be transmitted to the sensor diaphragm. The MPX4200A series pressure sensor
operating characteristics, and internal reliability and qualification tests are based on use of dry air as the pressure
media. Media, other than dry air, may have adverse effects on sensor performance and long–term reliability.
Contact the factory for information regarding media compatibility in your application.
5.0
4.5
4.0
OUTPUT (Volts)
3.5
TRANSFER FUNCTION:
Vout = VS* (0.005 x P–0.04) ± Error
VS = 5.1 Vdc
TEMP = 0 to 85°C
MAX
TYP
3.0
2.5
2.0
1.5
MIN
1.0
0.5
0
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
Freescale Semiconductor, Inc...
Figure 2. Cross–Sectional Diagram
(Not to Scale)
Figure 4. Output versus Absolute Pressure
3–86
For www.motorola.com/semiconductors
More Information On This Product,
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPX4200A SERIES
Transfer Function (MPX4200A)
Nominal Transfer Value: Vout = VS x (0.005 x P – 0.04)
Nominal Transfer Value: ± (Pressure Error x Temp. Factor x 0.005 x VS)
Nominal Transfer Value: VS = 5.1 ± 0.25 Vdc
Temperature Error Band
MPX4200A Series
4.0
Temperature
Error
Factor
2.0
Temp
Multiplier
– 40
–18
0 to 85
+125
3
1.56
1
2
1.0
0.0
–40
–20
0
20
40
60
80
100
120
140
Temperature in C°
NOTE: The Temperature Multiplier is a linear response from 0°C to –40°C and from 85°C to 125°C
Pressure Error Band
6.0
4.0
Pressure Error (kPa)
Freescale Semiconductor, Inc...
3.0
2.0
20
40
60
80
Pressure in kPa
100 120 140 160 180 200
–2.0
– 4.0
MPX4200A Series
– 6.0
Pressure
Error (Max)
20 kPa
40 kPa
160 kPa
200 kPa
± 4.2 (kPa)
± 2.4 (kPa)
± 2.4 (kPa)
± 3.2 (kPa)
ORDERING INFORMATION
Device Type
Basic Element
Options
Absolute, Element
Motorola Sensor Device Data
Case No.
Case 867
MPX Series Order No.
MPX4200A
www.motorola.com/semiconductors
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Information On This Product,
Go to: www.freescale.com
Marking
MPX4200A
3–87
Freescale Semiconductor, Inc.
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Integrated Silicon Pressure Sensor
MPX4250A
Manifold Absolute Pressure Sensor
MPXA4250A
On-Chip Signal Conditioned,
SERIES
Temperature Compensated
Freescale Semiconductor, Inc...
and Calibrated
INTEGRATED
PRESSURE SENSOR
20 to 250 kPa (2.9 to 36.3 psi)
0.2 to 4.9 V OUTPUT
The Motorola MPX4250A/MPXA4250A series Manifold Absolute Pressure (MAP)
sensor for engine control is designed to sense absolute air pressure within the intake
manifold. This measurement can be used to compute the amount of fuel required for
each cylinder.
The MPX4250A/MPXA4250A series piezoresistive transducer is a state–of–the–art
monolithic silicon pressure sensor designed for a wide range of applications, particularly
those employing a microcontroller or microprocessor with A/D inputs. This transducer
combines advanced micromachining techniques, thin–film metallization and bipolar
processing to provide an accurate, high–level analog output signal that is proportional to
the applied pressure. The small form factor and high reliability of on–chip integration
make the Motorola sensor a logical and economical choice for the automotive system
engineer.
UNIBODY PACKAGE
SMALL OUTLINE PACKAGE
Features
• 1.5% Maximum Error Over 0° to 85°C
BASIC CHIP
CARRIER ELEMENT
CASE 867, STYLE 1
• Specifically Designed for Intake Manifold Absolute
Pressure Sensing in Engine Control Systems
• Patented Silicon Shear Stress Strain Gauge
• Temperature Compensated Over – 40° to +125°C
PORT OPTION
CASE 482
• Offers Reduction in Weight and Volume Compared
to Existing Hybrid Modules
• Durable Epoxy Unibody Element or Thermoplastic
Small Outline, Surface Mount Package
• Ideal for Non–Automotive Applications
Application Examples
• Turbo Boost Engine Control
• Ideally Suited for Microprocessor or Microcontroller–
Based Systems
PORT OPTION
CASE 867B, STYLE 1
PORT OPTION
CASE 482A
PIN NUMBER
PIN NUMBER
VS
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
GND
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
Vout
1
N/C
5
N/C
1
Vout
4
N/C
2
VS
Gnd
6
N/C
2
Gnd
5
N/C
3
7
N/C
3
VS
6
N/C
4
Vout
8
N/C
NOTE: Pins 1, 5, 6, and 7 are internal
device connections. Do not connect
to external circuitry or ground. Pin 1
is noted by the notch in the lead.
NOTE: Pins 4, 5, and 6 are internal
device connections. Do not connect
to external circuitry or ground. Pin 1
is noted by the notch in the lead.
PINS 4, 5, AND 6 ARE NO CONNECTS FOR
UNIBODY DEVICE
PINS 1, 5, 6, 7, AND 8 ARE NO CONNECTS
FOR SMALL OUTLINE PACKAGE DEVICE
Figure 1. Fully Integrated Pressure Sensor
Schematic
REV 4
3–88
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor,MPX4250A
Inc.
MPXA4250A SERIES
MAXIMUM RATINGS(1)
Parametrics
Maximum Pressure(2) (P1 > P2)
Storage Temperature
Operating Temperature
Symbol
Value
Unit
Pmax
1000
kPa
Tstg
– 40 to +125
°C
TA
– 40 to +125
°C
NOTES:
1. TC = 25°C unless otherwise noted.
2. Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 5.1 Vdc, TA = 25°C unless otherwise noted, P1 > P2, Decoupling circuit shown in Figure 3
required to meet electrical specifications.)
Symbol
Min
Typ
Max
Unit
Pressure Range(1)
POP
20
—
250
kPa
Supply Voltage(2)
VS
4.85
5.1
5.35
Vdc
Supply Current
Io
—
7.0
10
mAdc
Freescale Semiconductor, Inc...
Characteristic
Minimum Pressure Offset(3)
@ VS = 5.1 Volts
(0 to 85°C)
Voff
0.133
0.204
0.274
Vdc
Full Scale Output(4)
@ VS = 5.1 Volts
(0 to 85°C)
VFSO
4.826
4.896
4.966
Vdc
Full Scale Span(5)
@ VS = 5.1 Volts
(0 to 85°C)
VFSS
—
4.692
—
Vdc
Accuracy(6)
(0 to 85°C)
—
—
—
±1.5
%VFSS
∆V/∆P
—
20
—
mV/kPa
Response Time(7)
tR
—
1.0
—
msec
Output Source Current at Full Scale Output
lo+
—
0.1
—
mAdc
Warm–Up Time(8)
—
—
20
—
msec
Offset Stability(9)
—
—
± 0.5
—
%VFSS
Sensitivity
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range.
3. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
4. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
5. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
6. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation over the temperature range of 0° to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0° to 85°C, relative
to 25°C.
• Variation from Nominal: The variation from nominal values, for Offset or Full Scale Span, as a percent of VFSS, at 25°C.
7. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
8. Warm–up is defined as the time required for the product to meet the specified output voltage after the Pressure has been stabilized.
9. Offset stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
MECHANICAL CHARACTERISTICS
Characteristics
Typ
Unit
Weight, Basic Element (Case 867)
4.0
Grams
Weight, Small Outline Package (Case 482)
1.5
Grams
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–89
Freescale Semiconductor, Inc.
MPX4250A MPXA4250A SERIES
FLUOROSILICONE
DIE COAT
+5 V
STAINLESS STEEL
METAL COVER
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
DIE
P1
WIRE BOND
LEAD FRAME
P2
Vout
EPOXY
CASE
OUTPUT
Vs
IPS
RTV DIE
BOND
m
1.0 F
m
GND
0.01 F
470 pF
SEALED VACUUM REFERENCE
Figure 3. Recommended power supply decoupling
and output filtering.
For additional output filtering, please refer to
Application Note AN1646.
Contact the factory for information regarding media compatibility in your application.
Figure 3 shows the recommended decoupling circuit for interfacing the output of the integrated sensor to the A/D input
of a microprocessor or microcontroller.
Figure 4 shows the sensor output signal relative to pressure input. Typical, minimum, and maximum output curves
are shown for operation over temperature range of 0° to
85°C using the decoupling circuit shown in Figure 3. The
output will saturate outside of the specified pressure range.
Figure 2 illustrates the absolute pressure sensing chip in
the basic chip carrier (Case 867). A fluorosilicone gel isolates the die surface and wire bonds from the environment,
while allowing the pressure signal to be transmitted to the
sensor diaphragm.
The MPX4250A/MPXA4250A series pressure sensor operating characteristics and internal reliability and qualification tests are based on use of dry air as the pressure
media. Media, other than dry air, may have adverse effects on sensor performance and long–term reliability.
5.0
4.5
4.0
OUTPUT (Volts)
3.5
TRANSFER FUNCTION:
Vout = VS* (0.004 x P–0.04) ± Error
VS = 5.1 Vdc
TEMP = 0 to 85°C
MAX
TYP
3.0
2.5
2.0
1.5
MIN
1.0
0.5
0
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
220
230
240
250
260
Freescale Semiconductor, Inc...
Figure 2. Cross–Sectional Diagram
(Not to Scale)
PRESSURE (ref: to sealed vacuum) in kPa
Figure 4. Output versus Absolute Pressure
3–90
For www.motorola.com/semiconductors
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Motorola Sensor Device Data
Freescale Semiconductor,MPX4250A
Inc.
MPXA4250A SERIES
Transfer Function
Nominal Transfer Value: Vout = VS (P x 0.004 – 0.04)
Nominal Transfer Value: +/– (Pressure Error x Temp. Factor x 0.004 x VS)
Nominal Transfer Value: VS = 5.1 V ± 0.25 Vdc
Temperature Error Band
4.0
3.0
Temperature
Error
Factor
2.0
Temp
Multiplier
– 40
0 to 85
+125
3
1
3
Freescale Semiconductor, Inc...
1.0
0.0
–40
–20
0
20
40
60
80
100
120
140
Temperature in C°
NOTE: The Temperature Multiplier is a linear response from 0° to –40°C and from 85° to 125°C.
Pressure Error Band
5.0
4.0
Pressure
Error
(kPa)
3.0
2.0
1.0
0
–1.0
–2.0
–3.0
–4.0
–5.0
Motorola Sensor Device Data
0
25
50
75 100 125 150 175 200 225 250
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Information On This Product,
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Pressure
(kPa)
Pressure
Error (Max)
20 to 250 kPa
± 3.45 (kPa)
3–91
Freescale Semiconductor, Inc.
MPX4250A MPXA4250A SERIES
ORDERING INFORMATION – UNIBODY PACKAGE (CASE 867)
The MPX4250A series pressure sensors are available in the basic element package or with pressure
port fittings that provide mounting ease and barbed hose connections.
Device Type/Order No.
Options
Case No.
Marking
MPX4250A
MPX4250A
Basic Element
867
MPX4250AP
Ported Element
867B
MPX4250AP
ORDERING INFORMATION – SMALL OUTLINE PACKAGE (CASE 482)
The MPXA4250A series pressure sensors are available in the basic element package or with a
pressure port fitting. Two packing options are offered for each type.
Freescale Semiconductor, Inc...
Device Type/Order No.
Case No.
Packing Options
Device Marking
MPXA4250A6U
482
Rails
MPXA4250A
MPXA4250A6T1
482
Tape and Reel
MPXA4250A
MPXA4250AC6U
482A
Rails
MPXA4250A
MPXA4250AC6T1
482A
Tape and Reel
MPXA4250A
INFORMATION FOR USING THE SMALL OUTLINE PACKAGE (CASE 482)
MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS
Surface mount board layout is a critical portion of the total
design. The footprint for the surface mount packages must
be the correct size to ensure proper solder connection interface between the board and the package. With the correct
fottprint, the packages will self align when subjected to a
solder reflow process. It is always recommended to design
boards with a solder mask layer to avoid bridging and shorting between solder pads.
0.100 TYP 8X
2.54
0.660
16.76
0.060 TYP 8X
1.52
0.300
7.62
0.100 TYP 8X
2.54
inch
mm
SCALE 2:1
Figure 5. SOP Footprint (Case 482)
3–92
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Integrated Silicon Pressure Sensor
MPX4250D
On-Chip Signal Conditioned,
SERIES
Temperature Compensated
Freescale Semiconductor, Inc...
and Calibrated
The MPX4250D series piezoresistive transducer is a state–of–the–art monolithic
silicon pressure sensor designed for a wide range of applications, particularly those
employing a microcontroller or microprocessor with A/D inputs. This transducer
combines advanced micromachining techniques, thin–film metallization, and bipolar
processing to provide an accurate, high–level analog output signal that is proportional to
the applied pressure. The small form factor and high reliability of on–chip integration
make the Motorola sensor a logical and economical choice for the automotive system
engineer.
INTEGRATED
PRESSURE SENSOR
0 to 250 kPa (0 to 36.3 psi)
0.2 to 4.9 Volts Output
UNIBODY PACKAGE
Features
• Differential and Gauge Applications Available
• 1.4% Maximum Error Over 0° to 85°C
• Patented Silicon Shear Stress Strain Gauge
BASIC CHIP
CARRIER ELEMENT
CASE 867, STYLE 1
• Temperature Compensated Over – 40° to +125°C
• Offers Reduction in Weight and Volume Compared to Existing Hybrid Modules
• Durable Epoxy Unibody Element
Applications
• Ideally Suited for Microprocessor or Microcontroller–Based Systems
VS
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
GAUGE PORT OPTION
CASE 867B, STYLE 1
Vout
PINS 4, 5 AND 6 ARE NO CONNECTS FOR
UNIBODY DEVICE
GND
Figure 1. Fully Integrated Pressure Sensor Schematic
DUAL PORT OPTION
CASE 867C, STYLE 1
PIN NUMBER
1
Vout
4
N/C
2
Gnd
5
N/C
3
VS
6
N/C
NOTE: Pins 4, 5, and 6 are internal
device connections. Do not connect
to external circuitry or ground. Pin 1
is noted by the notch in the lead.
REV 3
Motorola Sensor Device Data
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Information On This Product,
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3–93
MPX4250D SERIES
Freescale Semiconductor, Inc.
MAXIMUM RATINGS(1)
Parametrics
Maximum Pressure(2) (P1 > P2)
Storage Temperature
Operating Temperature
Symbol
Value
Unit
Pmax
1000
kPa
Tstg
– 40° to +125°
°C
TA
– 40° to +125°
°C
NOTES:
1. TC = 25°C unless otherwise noted.
2. Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 5.1 Vdc, TA = 25°C unless otherwise noted, P1 > P2, Decoupling circuit shown in Figure 3
required to meet electrical specifications.)
Symbol
Min
Typ
Max
Unit
Pressure Range(1)
POP
0
—
250
kPa
Supply Voltage(2)
VS
4.85
5.1
5.35
Vdc
Supply Current
Io
—
7.0
10
mAdc
Freescale Semiconductor, Inc...
Characteristic
Minimum Pressure Offset(3)
@ VS = 5.1 Volts
(0 to 85°C)
VOFF
0.139
0.204
0.269
Vdc
Full Scale Output(4)
@ VS = 5.1 Volts
(0 to 85°C)
VFSO
4.844
4.909
4.974
Vdc
Full Scale Span(5)
@ VS = 5.1 Volts
(0 to 85°C)
VFSS
—
4.705
—
Vdc
Accuracy(6)
(0 to 85°C)
—
—
—
±1.4
%VFSS
∆V/∆P
—
18.8
—
mV/kPa
Response Time(7)
tR
—
1.0
—
msec
Output Source Current at Full Scale Output
lo+
—
0.1
—
mAdc
Warm–Up Time(8)
—
—
20
—
msec
Offset Stability(9)
—
—
± 0.5
—
%VFSS
Sensitivity
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range.
3. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
4. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
5. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
6. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation over the temperature range of 0° to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0° to 85°C, relative
to 25°C.
• Variation from Nominal: The variation from nominal values, for Offset or Full Scale Span, as a percent of VFSS, at 25°C.
7. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
8. Warm–up is defined as the time required for the product to meet the specified output voltage after the Pressure has been stabilized.
9. Offset stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
MECHANICAL CHARACTERISTICS
Characteristics
Weight, Basic Element (Case 867)
3–94
Typ
Unit
4.0
Grams
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
FLUOROSILICONE
DIE COAT
DIE
+5 V
STAINLESS STEEL
METAL COVER
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
P1
Vout
WIRE BOND
LEAD
FRAME
MPX4250D SERIES
OUTPUT
Vs
IPS
RTV DIE
BOND
m
1.0 F
m
GND
0.01 F
470 pF
P2
EPOXY CASE
Figure 3. Recommended power supply decoupling
and output filtering.
For additional output filtering, please refer to
Application Note AN1646.
Figure 3 shows the recommended decoupling circuit for interfacing the output of the integrated sensor to the A/D input
of a microprocessor or microcontroller.
Figure 4 shows the sensor output signal relative to pressure input. Typical, minimum, and maximum output curves
are shown for operation over a temperature range of 0° to
85°C using the decoupling circuit shown in Figure 3. The
output will saturate outside of the specified pressure range.
Figure 2 illustrates the differential/gauge pressure sensing
chip in the basic chip carrier (Case 867). A fluorosilicone gel
isolates the die surface and wire bonds from the environment, while allowing the pressure signal to be transmitted to
the sensor diaphragm.
The MPX4250D series pressure sensor operating characteristics and internal reliability and qualification tests are based
on use of dry air as the pressure media. Media, other than dry
air, may have adverse effects on sensor performance and
long–term reliability. Contact the factory for information
regarding media compatibility in your application.
5.0
4.5
4.0
OUTPUT (Volts)
3.5
MAX
TRANSFER FUNCTION:
Vout = VS* (0.00369*P + 0.04) ± Error
VS = 5.1 Vdc
TEMP = 0 to 85°C
TYP
3.0
2.5
2.0
1.5
MIN
1.0
0
250
260
0.5
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
Freescale Semiconductor, Inc...
Figure 2. Cross–Sectional Diagram
(Not to Scale)
PRESSURE in kPa
Figure 4. Output versus Differential Pressure
Motorola Sensor Device Data
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3–95
Freescale Semiconductor, Inc.
MPX4250D SERIES
Transfer Function (MPX4250D)
Nominal Transfer Value: Vout = VS x (0.00369 x P + 0.04)
Nominal Transfer Value:
(Pressure Error x Temp. Factor x 0.00369 x VS)
Nominal Transfer Value: VS = 5.1
0.25 Vdc
"
"
Temperature Error Band
4.0
Freescale Semiconductor, Inc...
3.0
Temperature
Error
Factor
2.0
Temp
Multiplier
– 40
0 to 85
+125
3
1
3
1.0
0.0
–40
–20
0
20
40
60
80
100
120
140
Temperature in °C
NOTE: The Temperature Multiplier is a linear response from 0° to –40°C and from 85° to 125°C.
Pressure Error Band
5.0
4.0
Pressure
Error
(kPa)
3.0
2.0
1.0
0
–1.0
–2.0
–3.0
–4.0
–5.0
0
25
50
75 100 125 150 175 200 225 250
Pressure
(kPa)
Pressure
Error (max)
0 to 250 kPa
± 3.45 kPa
ORDERING INFORMATION
The MPX4250D series silicon pressure sensors are available in the basic element package or with
pressure port fittings that provide mounting ease and barbed hose connections.
Device Type/Order No.
Options
Case No.
Marking
867
MPX4250D
MPX4250D
Basic Element
MPX4250GP
Gauge Ported Element
867B
MPX4250GP
MPX4250DP
Dual Ported Element
867C
MPX4250DP
3–96
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Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
Integrated Silicon Pressure Sensor
On-Chip Signal Conditioned,
MPX5010
MPXV5010G
Temperature Compensated
Freescale Semiconductor, Inc...
and Calibrated
SERIES
Motorola Preferred Device
SMALL OUTLINE PACKAGE
The MPX5010/MPXV5010G series piezoresistive
transducers are state–of–the–art monolithic silicon pressure sensors designed for a wide range of applications, but
particularly those employing a microcontroller or microprocessor with A/D inputs. This transducer combines
advanced micromachining techniques, thin–film metallization, and bipolar processing to provide an accurate,
high level analog output signal that is proportional to the
applied pressure.
INTEGRATED
PRESSURE SENSOR
0 to 10 kPa (0 to 1.45 psi)
0.2 to 4.7 V Output
MPXV5010G6U
CASE 482
UNIBODY PACKAGE
Features
• 5.0% Maximum Error over 0° to 85°C
• Ideally Suited for Microprocessor or Microcontroller–
Based Systems
MPXV5010GC6U
CASE 482A
• Durable Epoxy Unibody and Thermoplastic (PPS)
Surface Mount Package
• Temperature Compensated over
MPX5010D
CASE 867
*40° to +125°C
• Patented Silicon Shear Stress Strain Gauge
• Available in Differential and Gauge Configurations
• Available in Surface Mount (SMT) or Through–hole
(DIP) Configurations
MPXV5010GC7U
CASE 482C
Application Examples
• Hospital Beds
• HVAC
• Respiratory Systems
MPX5010DP
CASE 867C
• Process Control
MPXV5010GP
CASE 1369
VS
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
Vout
PINS 1 AND 5 THROUGH 8 ARE NO CONNECTS
FOR SURFACE MOUNT PACKAGE
GND
PINS 4, 5, AND 6 ARE NO CONNECTS FOR
UNIBODY PACKAGE
Figure 1. Fully Integrated Pressure
Sensor Schematic
MPXV5010DP
CASE 1351
MPX5010GS
CASE 867E
PIN NUMBER
PIN NUMBER
1
N/C
5
N/C
1
Vout
4
N/C
2
6
N/C
2
Gnd
5
N/C
3
VS
Gnd
7
N/C
3
VS
6
N/C
4
Vout
8
N/C
NOTE: Pins 1, 5, 6, 7, and 8 are
internal device connections. Do not
connect to external circuitry or
ground. Pin 1 is noted by the notch
in the lead.
NOTE: Pins 4, 5, and 6 are internal
device connections. Do not connect
to external circuitry or ground. Pin 1
is noted by the notch in the lead.
REV 9
Motorola Sensor Device Data
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Information On This Product,
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3–97
Freescale Semiconductor, Inc.
MPX5010 MPXV5010G SERIES
MAXIMUM RATINGS(NOTE)
Parametrics
Symbol
Value
Unit
Pmax
75
kPa
Tstg
– 40 to +125
°C
TA
– 40 to +125
°C
Maximum Pressure (P1 > P2)
Storage Temperature
Operating Temperature
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 5.0 Vdc, TA = 25°C unless otherwise noted, P1 > P2. Decoupling circuit shown in Figure 3
required to meet specification.)
Freescale Semiconductor, Inc...
Characteristic
Symbol
Min
Typ
Max
Unit
Pressure Range(1)
POP
0
—
10
kPa
Supply Voltage(2)
VS
4.75
5.0
5.25
Vdc
Supply Current
Io
—
5.0
10
mAdc
Minimum Pressure Offset(3)
@ VS = 5.0 Volts
(0 to 85°C)
Voff
0
0.2
0.425
Vdc
Full Scale Output(4)
@ VS = 5.0 Volts
(0 to 85°C)
VFSO
4.475
4.7
4.925
Vdc
Full Scale Span(5)
@ VS = 5.0 Volts
(0 to 85°C)
VFSS
4.275
4.5
4.725
Vdc
Accuracy(6)
(0 to 85°C)
—
—
—
± 5.0
%VFSS
V/P
—
450
—
mV/kPa
tR
—
1.0
—
ms
Sensitivity
Response Time(7)
Output Source Current at Full Scale Output
IO+
—
0.1
—
mAdc
Warm–Up Time(8)
—
—
20
—
ms
Offset Stability(9)
—
—
± 0.5
—
%VFSS
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range.
3. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
4. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
5. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
6. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation over the temperature range of 0° to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0° to 85°C, relative
to 25°C.
• Variation from Nominal: The variation from nominal values, for Offset or Full Scale Span, as a percent of VFSS, at 25°C.
7. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
8. Warm–up Time is defined as the time required for the product to meet the specified output voltage after the Pressure has been stabilized.
9. Offset Stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
MECHANICAL CHARACTERISTICS
Characteristics
Typ
Unit
Weight, Basic Element (Case 867)
4.0
grams
Weight, Basic Element (Case 482)
1.5
grams
3–98
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Freescale Semiconductor, MPX5010
Inc.
MPXV5010G SERIES
ON–CHIP TEMPERATURE COMPENSATION, CALIBRATION AND SIGNAL CONDITIONING
DIE
FLUOROSILICONE
GEL DIE COAT
sensor performance and long–term reliability. Contact the
factory for information regarding media compatibility in your
application.
Figure 3 shows the recommended decoupling circuit for interfacing the integrated sensor to the A/D input of a microprocessor or microcontroller. Proper decoupling of the power
supply is recommended.
Figure 4 shows the sensor output signal relative to pressure input. Typical, minimum, and maximum output curves
are shown for operation over a temperature range of 0° to
85°C using the decoupling circuit shown in Figure 4. The
output will saturate outside of the specified pressure range.
+5 V
STAINLESS
STEEL CAP
P1
Vout
WIRE BOND
IPS
m
m
1.0 F
LEAD
FRAME
OUTPUT
Vs
THERMOPLASTIC
CASE
GND
0.01 F
470 pF
P2
DIE BOND
DIFFERENTIAL SENSING
ELEMENT
Figure 2. Cross–Sectional Diagram SOP
(Not to Scale)
Figure 3. Recommended power supply decoupling
and output filtering.
For additional output filtering, please refer to
Application Note AN1646.
5.0
OUTPUT (V)
Freescale Semiconductor, Inc...
The performance over temperature is achieved by integrating the shear–stress strain gauge, temperature compensation, calibration and signal conditioning circuitry onto a single
monolithic chip.
Figure 2 illustrates the Differential or Gauge configuration in
the basic chip carrier (Case 482). A fluorosilicone gel isolates
the die surface and wire bonds from the environment, while
allowing the pressure signal to be transmitted to the sensor
diaphragm.
The MPX5010 and MPXV5010G series pressure sensor
operating characteristics, and internal reliability and qualification tests are based on use of dry air as the pressure media. Media, other than dry air, may have adverse effects on
TRANSFER FUNCTION:
4.5 V = V *(0.09*P+0.04) ± ERROR
out S
4.0 VS = 5.0 Vdc
TEMP = 0 to 85°C
3.5
3.0
2.5
2.0
1.5
TYPICAL
MAX
1.0
MIN
0.5
0
0
1
2
3
7
4
5
6
8
DIFFERENTIAL PRESSURE (kPa)
9
10
11
Figure 4. Output versus Pressure Differential
Motorola Sensor Device Data
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3–99
Freescale Semiconductor, Inc.
MPX5010 MPXV5010G SERIES
Transfer Function (MPX5010, MPXV5010G)
Nominal Transfer Value: Vout = VS x (0.09 x P + 0.04)
Nominal Transfer Value: ± (Pressure Error x Temp. Factor x 0.09 x VS)
Nominal Transfer Value: VS = 5.0 V ± 0.25 Vdc
Temperature Error Band
MPX5010, MPXV5010G Series
4.0
Freescale Semiconductor, Inc...
3.0
Temperature
Error
Factor
2.0
Temp
Multiplier
– 40
0 to 85
+125
3
1
3
1.0
0.0
–40
–20
0
20
40
60
80
100
120
140
Temperature in C°
NOTE: The Temperature Multiplier is a linear response from 0° to –40°C and from 85° to 125°C.
Pressure Error Band
0.5
0.4
0.3
Pressure
Error
(kPa)
0.2
0.1
0
–0.1
–0.2
0
1
2
3
4
5
6
7
8
9
10
Pressure (kPa)
–0.3
–0.4
–0.5
3–100
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Pressure
Error (Max)
0 to 10 kPa
± 0.5 kPa
Motorola Sensor Device Data
Freescale Semiconductor, MPX5010
Inc.
MPXV5010G SERIES
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing fluoro silicone gel
which protects the die from harsh media. The Motorola MPX
Freescale Semiconductor, Inc...
Part Number
pressure sensor is designed to operate with positive differential pressure applied, P1 > P2.
The Pressure (P1) side may be identified by using the table
below:
Pressure (P1)
Side Identifier
Case Type
MPX5010D
867C
Stainless Steel Cap
MPX5010DP
867C
Side with Part Marking
MPX5010GP
867B
Side with Port Attached
MPX5010GS
867E
Side with Port Attached
MPX5010GSX
867F
Side with Port Attached
MPXV5010G6U
482
Stainless Steel Cap
MPXV5010G7U
482B
Stainless Steel Cap
MPXV5010GC6U/T1
482A
Side with Port Attached
MPXV5010GC7U
482C
Side with Port Attached
MPXV5010GP
1369
Side with Port Attached
MPXV5010DP
1351
Side with Part Marking
ORDERING INFORMATION — UNIBODY PACKAGE (MPX5010 SERIES)
MPX Series
Device Type
Options
Order Number
Case Type
Device Marking
Basic Element
Differential
867
MPX5010D
MPX5010D
Ported Elements
Differential, Dual Port
867C
MPX5010DP
MPX5010DP
Gauge
867B
MPX5010GP
MPX5010GP
Gauge, Axial
867E
MPX5010GS
MPX5010D
Gauge, Axial PC Mount
867F
MPX5010GSX
MPX5010D
ORDERING INFORMATION — SMALL OUTLINE PACKAGE (MPXV5010G SERIES)
Device Type
Options
Case No.
Basic Elements
Gauge, Element Only, SMT
482
MPXV5010G6U
Rails
MPXV5010G
Gauge, Element Only, DIP
482B
MPXV5010G7U
Rails
MPXV5010G
Gauge, Axial Port, SMT
482A
MPXV5010GC6U
Rails
MPXV5010G
Gauge, Axial Port, DIP
482C
MPXV5010GC7U
Rails
MPXV5010G
Gauge, Axial Port, SMT
482A
MPXV5010GC6T1
Tape and Reel
MPXV5010G
Gauge, Side Port, SMT
1369
MPXV5010GP
Trays
MPXV5010G
Differential, Dual Port, SMT
1351
MPXV5010DP
Trays
MPXV5010G
Ported Elements
Motorola Sensor Device Data
MPX Series Order No.
Packing Options
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Information On This Product,
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Marking
3–101
Freescale Semiconductor, Inc.
MPX5010 MPXV5010G SERIES
MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS
Surface mount board layout is a critical portion of the total
design. The footprint for the surface mount packages must
be the correct size to ensure proper solder connection interface between the board and the package. With the correct
footprint, the packages will self align when subjected to a
solder reflow process. It is always recommended to design
boards with a solder mask layer to avoid bridging and shorting between solder pads.
0.100 TYP 8X
2.54
0.660
16.76
Freescale Semiconductor, Inc...
0.060 TYP 8X
1.52
0.300
7.62
0.100 TYP 8X
2.54
inch
mm
SCALE 2:1
Figure 5. SOP Footprint (Case 482)
3–102
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Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
MPX5050
Integrated Silicon Pressure Sensor
MPXV5050G
On-Chip Signal Conditioned,
Temperature Compensated
SERIES
and Calibrated
Motorola Preferred Device
The MPX5050/MPXV5050G series piezoresistive transducer is a state–of–the–art
monolithic silicon pressure sensor designed for a wide range of applications, but
particularly those employing a microcontroller or microprocessor with A/D inputs. This
patented, single element transducer combines advanced micromachining techniques,
thin–film metallization, and bipolar processing to provide an accurate, high level analog
output signal that is proportional to the applied pressure.
INTEGRATED
PRESSURE SENSOR
0 to 50 kPa (0 to 7.25 psi)
0.2 to 4.7 Volts Output
Freescale Semiconductor, Inc...
Features
UNIBODY PACKAGE
• 2.5% Maximum Error over 0° to 85°C
• Ideally suited for Microprocessor or Microcontroller–Based Systems
• Temperature Compensated Over – 40° to +125°C
• Patented Silicon Shear Stress Strain Gauge
• Durable Epoxy Unibody Element
• Easy–to–Use Chip Carrier Option
MPX5050D
CASE 867
VS
SMALL OUTLINE PACKAGE
SURFACE MOUNT
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
GND
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
Vout
PINS 4, 5, AND 6 ARE NO CONNECTS FOR
UNIBODY DEVICE
PINS 1, 5, 6, 7, AND 8 ARE NO CONNECTS
FOR SMALL OUTLINE PACKAGE DEVICE
MPX5050GP
CASE 867B
MPXV5050GP
CASE 1369
Figure 1. Fully Integrated Pressure Sensor
Schematic
MPXV5050DP
CASE 1351
MPX5050DP
CASE 867C
PIN NUMBER
1
N/C
5
N/C
2
6
N/C
3
VS
Gnd
7
N/C
4
Vout
8
N/C
NOTE: Pins 1, 5, 6, 7, and 8 are
internal device connections. Do not
connect to external circuitry or
ground. Pin 1 is noted by the notch
in the lead.
PIN NUMBER
1
Vout
4
N/C
2
Gnd
5
N/C
3
VS
6
N/C
NOTE: Pins 4, 5, and 6 are internal
device connections. Do not connect
to external circuitry or ground. Pin 1
is noted by the notch in the lead.
REV 6
Motorola Sensor Device Data
www.motorola.com/semiconductors
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Information On This Product,
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3–103
Freescale Semiconductor, Inc.
MPX5050 MPXV5050G SERIES
MAXIMUM RATINGS(NOTE)
Parametrics
Maximum Pressure (P1 > P2)
Storage Temperature
Operating Temperature
Symbol
Value
Unit
Pmax
200
kPa
Tstg
– 40° to +125°
°C
TA
– 40° to +125°
°C
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 5.0 Vdc, TA = 25°C unless otherwise noted, P1 > P2. Decoupling circuit shown in Figure 4
required to meet electrical specifications.)
Symbol
Freescale Semiconductor, Inc...
Characteristic
Min
Pressure Range(1)
POP
0
Supply Voltage(2)
VS
4.75
Supply Current
Io
—
Typ
Max
Unit
—
50
kPa
5.0
5.25
Vdc
7.0
10.0
mAdc
Minimum Pressure Offset(3)
@ VS = 5.0 Volts
(0 to 85°C)
Voff
0.088
0.20
0.313
Vdc
Full Scale Output(4)
@ VS = 5.0 Volts
(0 to 85°C)
VFSO
4.587
4.70
4.813
Vdc
Full Scale Span(5)
@ VS = 5.0 Volts
(0 to 85°C)
VFSS
—
4.50
—
Vdc
—
—
—
"2.5
%VFSS
V/P
—
90
—
mV/kPa
Response Time(7)
tR
—
1.0
—
ms
Output Source Current at Full Scale Output
Io+
—
0.1
—
mAdc
Warm–Up Time(8)
—
—
20
—
ms
Offset Stability(9)
—
—
—
%VFSS
Accuracy(6)
Sensitivity
"0.5
NOTES:
1. 1.0kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range.
3. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
4. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
5. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
6. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from
minimum or maximum rated pressure at 25°C.
• TcSpan:
Output deviation over the temperature range of 0° to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum pressure applied, over the temperature range of 0° to 85°C, relative
to 25°C.
• Variation from Nominal: The variation from nominal values, for Offset or Full Scale Span, as a percent of VFSS at 25°C.
7. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
8. Warm–up Time is defined as the time required for the product to meet the specified output voltage after the Pressure has been stabilized.
9. Offset Stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
MECHANICAL CHARACTERISTICS
Characteristics
Typ
Unit
Weight, Basic Element (Case 867)
4.0
grams
Weight, Basic Element (Case 1369)
1.5
grams
3–104
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More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, MPX5050
Inc.
MPXV5050G SERIES
Figure 3 illustrates the Differential/Gauge Sensing Chip in
the basic chip carrier (Case 867). A fluorosilicone gel isolates
the die surface and wire bonds from the environment, while
allowing the pressure signal to be transmitted to the sensor
diaphragm.
The MPX5050/MPXV5050G series pressure sensor operating characteristics, and internal reliability and qualification
tests are based on use of dry air as the pressure media. Media, other than dry air, may have adverse effects on sensor
performance and long–term reliability. Contact the factory for
information regarding media compatibility in your application.
Figure 2 shows the sensor output signal relative to pressure input. Typical, minimum, and maximum output curves
are shown for operation over a temperature range of 0° to
85°C using the decoupling circuit shown in Figure 4. The
output will saturate outside of the specified pressure range.
Figure 4 shows the recommended decoupling circuit for
interfacing the output of the integrated sensor to the A/D input of a microprocessor or microcontroller. Proper decoupling of the power supply is recommended.
OUTPUT (V)
Freescale Semiconductor, Inc...
5.0
TRANSFER FUNCTION:
4.5 Vout = VS*(0.018*P+0.04) ± ERROR
4.0 VS = 5.0 Vdc
TEMP = 0 to 85°C
3.5
3.0
TYPICAL
2.5
2.0
1.5
MIN
MAX
1.0
0.5
0
0
5
10
15
35 40
20
25
30
DIFFERENTIAL PRESSURE (kPa)
45
50
55
Figure 2. Output versus Pressure Differential
+5 V
FLUORO SILICONE
GEL DIE COAT
STAINLESS STEEL
METAL COVER
DIE
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
P1
Vout
EPOXY
PLASTIC
CASE
WIRE BOND
LEAD FRAME
DIFFERENTIAL/GAUGE ELEMENT
DIE
BOND
OUTPUT
Vs
IPS
m
1.0 F
m
0.01 F
GND
470 pF
P2
Figure 3. Cross–Sectional Diagram
(Not to Scale)
Motorola Sensor Device Data
Figure 4. Recommended power supply decoupling
and output filtering.
For additional output filtering, please refer to
Application Note AN1646.
www.motorola.com/semiconductors
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Information On This Product,
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3–105
Freescale Semiconductor, Inc.
MPX5050 MPXV5050G SERIES
Transfer Function
Nominal Transfer Value: Vout = VS (P x 0.018 + 0.04)
+/– (Pressure Error x Temp. Factor x 0.018 x VS)
VS = 5.0 V ± 0.25 Vdc
Temperature Error Band
MPX5050/MPXV5050G Series
4.0
Temp
3.0
– 40
0 to 85
+125
2.0
3
1
3
1.0
0.0
–40
–20
0
20
40
60
80
100
120
140
Temperature in °C
NOTE: The Temperature Multiplier is a linear response from 0° to –40°C and from 85° to 125°C.
Pressure Error Band
Error Limits for Pressure
3.0
2.0
Pressure Error (kPa)
Freescale Semiconductor, Inc...
Temperature
Error
Factor
Multiplier
1.0
0.0
Pressure (in kPa)
0
10
20
30
40
50
60
–1.0
– 2.0
– 3.0
3–106
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Pressure
Error (Max)
0 to 50 kPa
± 1.25 kPa
Motorola Sensor Device Data
Freescale Semiconductor, MPX5050
Inc.
MPXV5050G SERIES
PRESSURE (P1) / VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing fluorosilicone gel
which protects the die from harsh media. The Motorola MPX
Part Number
pressure sensor is designed to operate with positive differential pressure applied, P1 > P2.
The Pressure (P1) side may be identified by using the
table below:
Pressure (P1)
Side Identifier
Case Type
MPX5050D
867
Stainless Steel Cap
MPX5050DP
867C
Side with Part Marking
MPX5050GP
867B
Side with Port Attached
MPXV5050GP
1369
Side with Port Attached
MPXV5050DP
1351
Side with Part Marking
Freescale Semiconductor, Inc...
ORDERING INFORMATION — UNIBODY PACKAGE (MPX5050 SERIES)
MPX Series
Device Type
Options
Case Type
Order Number
Device Marking
Basic Element
Differential
867
MPX5050D
MPX5050D
Ported Elements
Differential Dual Ports
867C
MPX5050DP
MPX5050DP
Gauge
867B
MPX5050GP
MPX5050GP
ORDERING INFORMATION — SMALL OUTLINE PACKAGE (MPXV5050G SERIES)
Device Type
Ported Elements
Options
Case No.
MPX Series Order No.
Packing Options
Marking
Side Port
1369
MPXV5050GP
Trays
MPXV5050G
Dual Port
1351
MPXV5050DP
Trays
MPXV5050G
Motorola Sensor Device Data
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Information On This Product,
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3–107
Freescale Semiconductor, Inc.
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Integrated Silicon Pressure Sensor
MPX5100
On-Chip Signal Conditioned,
SERIES
Temperature Compensated
and Calibrated
The MPX5100 series piezoresistive transducer is a state–of–the–art monolithic silicon
pressure sensor designed for a wide range of applications, but particularly those
employing a microcontroller or microprocessor with A/D inputs. This patented, single
element transducer combines advanced micromachining techniques, thin–film metallization, and bipolar processing to provide an accurate, high level analog output signal that is
proportional to the applied pressure.
Freescale Semiconductor, Inc...
Features
INTEGRATED PRESSURE
SENSOR
0 to 100 kPa (0 to 14.5 psi)
15 to 115 kPa
(2.18 to 16.68 psi)
0.2 to 4.7 Volts Output
• 2.5% Maximum Error over 0° to 85°C
• Ideally suited for Microprocessor or Microcontroller–Based Systems
• Patented Silicon Shear Stress Strain Gauge
• Available in Absolute, Differential and Gauge Configurations
• Durable Epoxy Unibody Element
• Easy–to–Use Chip Carrier Option
MPX5100D
CASE 867
VS
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
Vout
PINS 4, 5 AND 6 ARE NO CONNECTS
MPX5100DP
CASE 867C
GND
Figure 1. Fully Integrated Pressure Sensor Schematic
MPX5100GSX
CASE 867F
PIN NUMBER
1
Vout
4
N/C
2
Gnd
5
N/C
3
VS
6
N/C
NOTE: Pins 4, 5, and 6 are internal
device connections. Do not connect
to external circuitry or ground. Pin 1
is noted by the notch in the lead.
REV 7
3–108
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPX5100 SERIES
MAXIMUM RATINGS(NOTE)
Parametrics
Maximum Pressure (P1 > P2)
Storage Temperature
Operating Temperature
Symbol
Value
Unit
Pmax
400
kPa
Tstg
– 40° to +125°
°C
TA
– 40° to +125°
°C
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 5.0 Vdc, TA = 25°C unless otherwise noted, P1 > P2. Decoupling circuit shown in Figure 4
required to meet electrical specifications.)
Characteristic
Pressure Range(1)
Gauge, Differential: MPX5100D
Absolute: MPX5100A
Supply Voltage(2)
Freescale Semiconductor, Inc...
Supply Current
Minimum Pressure Offset(3)
@ VS = 5.0 Volts
(0 to 85°C)
Symbol
Min
Typ
Max
Unit
POP
0
15
—
—
100
115
kPa
VS
4.75
5.0
5.25
Vdc
Io
—
7.0
10
mAdc
Voff
0.088
0.20
0.313
Vdc
Full Scale Output(4)
@ VS = 5.0 Volts
Differential and Absolute (0 to 85°C)
Vacuum(10)
VFSO
4.587
3.688
4.700
3.800
4.813
3.913
Vdc
Full Scale Span(5)
@ VS = 5.0 Volts
Differential and Absolute (0 to 85°C)
Vacuum(10)
VFSS
—
—
4.500
3.600
—
—
Vdc
—
—
—
"2.5
%VFSS
mV/kPa
Accuracy(6)
Sensitivity
V/P
—
45
—
Response Time(7)
tR
—
1.0
—
ms
Output Source Current at Full Scale Output
Io+
—
0.1
—
mAdc
Warm–Up Time(8)
—
—
20
—
ms
Offset Stability(9)
—
—
—
%VFSS
"0.5
NOTES:
1. 1.0kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range.
3. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
4. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
5. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
6. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from
minimum or maximum rated pressure at 25°C.
• TcSpan:
Output deviation over the temperature range of 0° to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum pressure applied, over the temperature range of 0° to 85°C, relative
to 25°C.
• Variation from Nominal: The variation from nominal values, for Offset or Full Scale Span, as a percent of VFSS at 25°C.
7. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
8. Warm–up Time is defined as the time required for the product to meet the specified output voltage after the Pressure has been stabilized.
9. Offset Stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
MECHANICAL CHARACTERISTICS
Characteristics
Weight, Basic Element (Case 867)
Motorola Sensor Device Data
Typ
Unit
4.0
grams
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3–109
Freescale Semiconductor, Inc.
MPX5100 SERIES
ON–CHIP TEMPERATURE COMPENSATION, CALIBRATION and SIGNAL CONDITIONING
5
VS = 5 Vdc
TA = 25°C
MPX5100
4
MAX
TYP
SPAN RANGE (TYP)
3.5
3
2.5
OUTPUT RANGE (TYP)
4.5
OUTPUT (V)
Figure 2 shows the sensor output signal relative to
pressure input. Typical, minimum, and maximum output curves are shown for operation over a temperature
range of 0° to 85°C using the decoupling circuit shown
in Figure 4. The output will saturate outside of the specified pressure range.
MIN
2
1.5
1
110
100
90
80
70
60
50
40
30
20
10
0
0
0.5
OFFSET
(TYP)
Freescale Semiconductor, Inc...
PRESSURE (kPa)
Figure 2. Output versus Pressure Differential
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
FLUORO SILICONE
GEL DIE COAT
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
STAINLESS STEEL
METAL COVER
EPOXY PLASTIC
CASE
DIE
WIRE BOND
LEAD FRAME
DIFFERENTIAL/GAUGE ELEMENT
FLUORO SILICONE
GEL DIE COAT
STAINLESS STEEL
METAL COVER
EPOXY PLASTIC
CASE
DIE
WIRE BOND
LEAD FRAME
DIE
BOND
ABSOLUTE ELEMENT
DIE
BOND
Figure 3. Cross–Sectional Diagrams
(Not to Scale)
Figure 3 illustrates both the Differential/Gauge and the
Absolute Sensing Chip in the basic chip carrier (Case 867).
A fluorosilicone gel isolates the die surface and wire bonds
from the environment, while allowing the pressure signal to
be transmitted to the sensor diaphragm.
The MPX5100 series pressure sensor operating characteristics, and internal reliability and qualification tests
are based on use of dry air as the pressure media. Media,
other than dry air, may have adverse effects on sensor
performance and long–term reliability. Contact the factory for information regarding media compatibility in your
application.
Figure 4 shows the recommended decoupling circuit for
interfacing the output of the integrated sensor to the A/D input of a microprocessor or microcontroller. Proper decoupling of the power supply is recommended.
+5 V
Vout
OUTPUT
Vs
IPS
m
1.0 F
m
0.01 F
GND
470 pF
Figure 4. Recommended power supply decoupling
and output filtering.
For additional output filtering, please refer to
Application Note AN1646.
3–110
For www.motorola.com/semiconductors
More Information On This Product,
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPX5100 SERIES
Transfer Function (MPX5100D, MPX5100G)
Nominal Transfer Value: Vout = VS (P x 0.009 + 0.04)
+/– (Pressure Error x Temp. Mult. x 0.009 x VS)
VS = 5.0 V ±5% P kPa
Temperature Error Multiplier
Break
Points
MPX5100D
Series
4.0
3.0
Temp
Multiplier
– 40
0 to 85
+125
3
1
3
1.0
0.0
–40
–20
0
20
40
60
80
100
120
130
140
Temperature in °C
NOTE: The Temperature Multiplier is a linear response from 0° to –40°C and from 85° to 125°C.
Pressure Error Band
Error Limits for Pressure
3.0
2.0
Error (kPa)
Freescale Semiconductor, Inc...
2.0
1.0
0.0
0
20
40
60
80
100
120
Pressure in kPa
–1.0
–2.0
MPX5100D Series
–3.0
Motorola Sensor Device Data
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Pressure
Error (max)
0 to 100 kPa
± 2.5 kPa
3–111
Freescale Semiconductor, Inc.
MPX5100 SERIES
Transfer Function (MPX5100A)
Nominal Transfer Value: Vout = VS (P x 0.009 – 0.095)
+/– (Pressure Error x Temp. Mult. x 0.009 x VS)
VS = 5.0 V ±5% P kPa
Temperature Error Multiplier
Break Points Series
MPX5100A
Temp
4.0
Multiplier
– 40
0 to 85
+125
3.0
3
1
3
1.0
0.0
–40
–20
0
20
40
60
80
100
120
130
140
Temperature in °C
NOTE: The Temperature Multiplier is a linear response from 0° to –40°C and from 85° to 125°C.
Pressure Error Band
Error Limits for Pressure
3.0
2.0
Error (kPa)
Freescale Semiconductor, Inc...
2.0
1.0
0.0
0
20
40
60
80
100
130
Pressure in kPa
–1.0
–2.0
MPX5100A Series
–3.0
Pressure
Error (max)
15 to 115 kPa ± 2.5 kPa
3–112
For www.motorola.com/semiconductors
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPX5100 SERIES
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing fluoro silicone gel
which protects the die from harsh media. The Motorola MPX
Part Number
pressure sensor is designed to operate with positive differential pressure applied, P1 > P2.
The Pressure (P1) side may be identified by using the
Table below:
Pressure (P1)
Side Identifier
Case Type
MPX5100A, MPX5100D
867
Stainless Steel Cap
MPX5100DP
867C
Side with Part Marking
MPX5100AP, MPX5100GP
867B
Side with Port Attached
MPX5100GSX
867F
Side with Port Attached
Freescale Semiconductor, Inc...
ORDERING INFORMATION:
The MPX5100 pressure sensor is available in absolute, differential, and gauge configurations. Devices are available in the
basic element package or with pressure port fittings that provide printed circuit board mounting ease and barbed hose pressure connections.
MPX Series
Device Name
Basic Element
Ported Elements
Motorola Sensor Device Data
Options
Case Type
Order Number
Device Marking
Absolute
867
MPX5100A
MPX5100A
Differential
867
MPX5100D
MPX5100D
Differential Dual Ports
867C
MPX5100DP
MPX5100DP
Absolute, Single Port
867B
MPX5100AP
MPX5100AP
Gauge, Single Port
867B
MPX5100GP
MPX5100GP
Gauge, Axial PC Mount
867F
MPX5100GSX
MPX5100D
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3–113
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
50 kPa Uncompensated
Silicon Pressure Sensors
MPX53
MPXV53GC
SERIES
The MPX53/MPXV53GC series silicon piezoresistive pressure sensors provide a very
accurate and linear voltage output — directly proportional to the applied pressure. These
standard, low cost, uncompensated sensors permit manufacturers to design and add
their own external temperature compensating and signal conditioning networks.
Compensation techniques are simplified because of the predictability of Motorola’s single
element strain gauge design.
0 to 50 kPa (0 – 7.25 psi)
60 mV FULL SCALE SPAN
(TYPICAL)
Features
• Low Cost
• Patented Silicon Shear Stress Strain Gauge Design
Freescale Semiconductor, Inc...
• Ratiometric to Supply Voltage
• Easy to Use Chip Carrier Package Options
SMALL OUTLINE
PACKAGE
UNIBODY PACKAGE
MPXV53GC6U
CASE 482A
MPX53D
CASE 344
• 60 mV Span (Typ)
• Differential and Gauge Options
Application Examples
• Air Movement Control
• Environmental Control Systems
• Level Indicators
• Leak Detection
• Medical Instrumentation
• Industrial Controls
• Pneumatic Control Systems
• Robotics
Figure 1 shows a schematic of the internal circuitry
on the stand–alone pressure sensor chip.
MPXV53GC7U
CASE 482C
+ VS
MPX53GP
CASE 344B
NOTE: Pin 1 is the notched pin.
+ Vout
PIN NUMBER
Sensor
– Vout
GND
1
Gnd
5
N/C
2
+Vout
VS
6
N/C
3
7
N/C
4
–Vout
8
N/C
Figure 1. Uncompensated Pressure Sensor Schematic
VOLTAGE OUTPUT versus APPLIED DIFFERENTIAL PRESSURE
The differential voltage output of the sensor is directly proportional to the differential
pressure applied.
The output voltage of the differential or gauge sensor increases with increasing
pressure applied to the pressure side (P1) relative to the vacuum side (P2). Similarly,
output voltage increases as increasing vacuum is applied to the vacuum side (P2)
relative to the pressure side (P1).
MPX53DP
CASE 344C
NOTE: Pin 1 is the notched pin.
Replaces MPX50/D
PIN NUMBER
1
Gnd
3
VS
2
+Vout
4
–Vout
REV 2
3–114
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPX53 MPXV53GC SERIES
MAXIMUM RATINGS(NOTE)
Rating
Symbol
Value
Unit
Pmax
200
kPa
Tstg
– 40 to +125
°C
Operating Temperature
TA
– 40 to +125
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
°C
Maximum Pressure (P1 > P2)
Storage Temperature
OPERATING CHARACTERISTICS (VS = 3.0 Vdc, TA = 25°C unless otherwise noted, P1 > P2)
Characteristic
Symbol
Min
Typ
Max
Unit
Pressure Range(1)
POP
0
—
50
kPa
Supply Voltage(2)
VS
—
3.0
6.0
Vdc
Supply Current
Io
—
6.0
—
mAdc
VFSS
45
60
90
mV
Full Scale Span(3)
Freescale Semiconductor, Inc...
Offset(4)
Voff
0
20
35
mV
Sensitivity
∆V/∆P
—
1.2
—
mV/kPa
Linearity(5)
—
– 0.6
—
0.4
%VFSS
Pressure Hysteresis(5) (0 to 50 kPa)
—
—
± 0.1
—
%VFSS
Temperature Hysteresis(5) (– 40°C to +125°C)
—
—
± 0.5
—
%VFSS
Temperature Coefficient of Full Scale Span(5)
TCVFSS
– 0.22
—
– 0.16
%VFSS/°C
TCVoff
—
± 15
—
µV/°C
TCR
0.31
—
0.37
%Zin/°C
Zin
355
—
505
Ω
Temperature Coefficient of Offset(5)
Temperature Coefficient of Resistance(5)
Input Impedance
Zout
750
—
1875
Ω
Response Time(6) (10% to 90%)
tR
—
1.0
—
ms
Warm–Up
—
—
20
—
ms
Offset Stability(7)
—
—
± 0.5
—
%VFSS
Output Impedance
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range. Operating the device above the specified excitation range may induce additional
error due to device self–heating.
3. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
4. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
5. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure, using end point method, over the specified
pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation at full rated pressure over the temperature range of 0 to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative
to 25°C.
• TCR:
Zin deviation with minimum rated pressure applied, over the temperature range of – 40°C to +125°C,
relative to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Offset stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
Motorola Sensor Device Data
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3–115
or by designing your system using the MPX2053 series
sensors.
Several approaches to external temperature compensation over both – 40 to +125°C and 0 to + 80°C ranges are
presented in Motorola Applications Note AN840.
TEMPERATURE COMPENSATION
Figure 2 shows the typical output characteristics of the
MPX53/MPXV53GC series over temperature.
The piezoresistive pressure sensor element is a semiconductor device which gives an electrical output signal proportional to the pressure applied to the device. This device uses
a unique transverse voltage diffused semiconductor strain
gauge which is sensitive to stresses produced in a thin silicon diaphragm by the applied pressure.
Because this strain gauge is an integral part of the silicon
diaphragm, there are no temperature effects due to differences in the thermal expansion of the strain gauge and the
diaphragm, as are often encountered in bonded strain gauge
pressure sensors. However, the properties of the strain
gauge itself are temperature dependent, requiring that the
device be temperature compensated if it is to be used over
an extensive temperature range.
Temperature compensation and offset calibration can be
achieved rather simply with additional resistive components,
LINEARITY
Linearity refers to how well a transducer’s output follows
the equation: Vout = Voff + sensitivity x P over the operating
pressure range (see Figure 3). There are two basic methods
for calculating nonlinearity: (1) end point straight line fit or (2)
a least squares best line fit. While a least squares fit gives
the “best case” linearity error (lower numerical value), the
calculations required are burdensome.
Conversely, an end point fit will give the “worst case” error
(often more desirable in error budget calculations) and the
calculations are more straightforward for the user. Motorola’s specified pressure sensor linearities are based on the
end point straight line method measured at the midrange
pressure.
70
100
LINEARITY
60
90
70
– 40°C
+ 25°C
50
60
OUTPUT (mVdc)
MPX53
VS = 3 Vdc
P1 > P2
80
OUTPUT (mVdc)
Freescale Semiconductor, Inc...
MPX53 MPXV53GC SERIESFreescale Semiconductor, Inc.
SPAN
RANGE
(TYP)
+ 125°C
50
40
30
ACTUAL
40
SPAN
(VFSS)
30
THEORETICAL
20
20
OFFSET
(TYP)
10
0
PSI 0
kPa 0
1
2
10
3
20
4
5
30
6
40
7
10
OFFSET
(VOFF)
0
8
0
50
MAX
PRESSURE (kPA)
PRESSURE DIFFERENTIAL
Figure 2. Output versus Pressure Differential
SILICONE
DIE COAT
Figure 3. Linearity Specification Comparison
STAINLESS STEEL
METAL COVER
EPOXY
CASE
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
DIE
P1
WIRE BOND
POP
LEAD FRAME
P2
RTV DIE
BOND
Figure 4. Cross–Sectional Diagram (not to scale)
Figure 4 illustrates the differential or gauge configuration
in the unibody chip carrier (Case 344). A silicone gel isolates
the die surface and wire bonds from the environment, while
allowing the pressure signal to be transmitted to the silicon
diaphragm.
The MPX53/MPXV53GC series pressure sensor operating
3–116
characteristics and internal reliability and qualification tests
are based on use of dry air as the pressure media. Media
other than dry air may have adverse effects on sensor performance and long term reliability. Contact the factory for information regarding media compatibility in your application.
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More Information On This Product,
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPX53 MPXV53GC SERIES
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing silicone gel which
isolates the die from the environment. The Motorola presPart Number
Case Type
Pressure (P1) Side Identifier
MPX53D
344
Stainless Steel Cap
MPX53DP
344C
Side with Port Marking
MPX53GP
344B
Side with Port Attached
482A, 482C
Sides with Port Attached
MPXV53GC series
Freescale Semiconductor, Inc...
sure sensor is designed to operate with positive differential
pressure applied, P1 > P2.
The Pressure (P1) side may be identified by using the
table below:
ORDERING INFORMATION – UNIBODY PACKAGE
MPX53 series pressure sensors are available in differential and gauge configurations. Devices are available with basic
element package or with pressure port fittings which provide printed circuit board mounting ease and barbed hose pressure
connections.
MPX Series
Device Type
Options
Case Type
Order Number
Device Marking
Basic Element
Differential
Case 344
MPX53D
MPX53D
Ported Elements
Differential
Case 344C
MPX53DP
MPX53DP
Gauge
Case 344B
MPX53GP
MPX53GP
ORDERING INFORMATION — SMALL OUTLINE PACKAGE
The MPXV53GC series pressure sensors are available with a pressure port, surface mount or DIP leadforms, and two packing
options.
Device Order No.
Case No.
Packing Options
482A
Tape & Rail
MPXV53G
MPXV53GC6U
482A
Rails
MPXV53G
MPXV53GC7U
482C
Rails
MPXV53G
MPXV53GC6T1
Motorola Sensor Device Data
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Information On This Product,
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Marking
3–117
Freescale Semiconductor, Inc.
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Integrated Silicon Pressure Sensor
MPX5500
On-Chip Signal Conditioned,
SERIES
Temperature Compensated
and Calibrated
The MPX5500 series piezoresistive transducer is a state–of–the–art monolithic silicon
pressure sensor designed for a wide range of applications, but particularly those
employing a microcontroller or microprocessor with A/D inputs. This patented, single
element transducer combines advanced micromachining techniques, thin–film metallization, and bipolar processing to provide an accurate, high level analog output signal that
is proportional to the applied pressure.
INTEGRATED
PRESSURE SENSOR
0 to 500 kPa (0 to 72.5 psi)
0.2 to 4.7 Volts Output
Freescale Semiconductor, Inc...
Features
• 2.5% Maximum Error over 0° to 85°C
• Ideally suited for Microprocessor or Microcontroller–Based Systems
• Patented Silicon Shear Stress Strain Gauge
• Durable Epoxy Unibody Element
• Available in Differential and Gauge Configurations
MPX5500D
CASE 867
VS
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
Vout
PINS 4, 5 AND 6 ARE NO CONNECTS
MPX5500DP
CASE 867C
GND
Figure 1. Fully Integrated Pressure Sensor Schematic
PIN NUMBER
1
Vout
4
N/C
2
Gnd
5
N/C
3
VS
6
N/C
NOTE: Pins 4, 5, and 6 are internal
device connections. Do not connect
to external circuitry or ground. Pin 1
is noted by the notch in the lead.
REV 5
3–118
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPX5500 SERIES
MAXIMUM RATINGS(1)
Parametrics
Maximum Pressure(2) (P2
v 1 Atmosphere)
Storage Temperature
Operating Temperature
Symbol
Value
Unit
P1max
2000
kPa
Tstg
– 40° to +125°
°C
TA
– 40° to +125°
°C
NOTES:
1. Maximum Ratings apply to Case 867 only. Extended exposure at the specified limits may cause permanent damage or degradation to the
device.
2. This sensor is designed for applications where P1 is always greater than, or equal to P2. P2 maximum is 500 kPa.
OPERATING CHARACTERISTICS (VS = 5.0 Vdc, TA = 25°C unless otherwise noted, P1 > P2. Decoupling circuit shown in Figure 4
required to meet electrical specifications.)
Freescale Semiconductor, Inc...
Characteristic
Symbol
Min
Typ
Max
Unit
Pressure Range(1)
POP
0
—
500
kPa
Supply Voltage(2)
VS
4.75
5.0
5.25
Vdc
Supply Current
Io
—
7.0
10.0
mAdc
Zero Pressure Offset(3)
(0 to 85°C)
Voff
0.088
0.20
0.313
Vdc
Full Scale Output(4)
(0 to 85°C)
VFSO
4.587
4.70
4.813
Vdc
Full Scale Span(5)
(0 to 85°C)
VFSS
—
4.50
—
Vdc
—
—
—
"2.5
%VFSS
V/P
—
9.0
—
mV/kPa
Response Time(7)
tR
—
1.0
—
ms
Output Source Current at Full Scale Output
Io+
—
0.1
—
mAdc
Warm–Up Time(8)
—
—
20
—
ms
Accuracy(6)
Sensitivity
NOTES:
1. 1.0kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range.
3. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
4. Full Scale Output (VFSO) is defined as the output voltage at full rated pressure.
5. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
6. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from
minimum or maximum rated pressure at 25°C.
• TcSpan:
Output deviation over the temperature range of 0° to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum pressure applied, over the temperature range of 0° to 85°C, relative
to 25°C.
• Variation from Nominal: The variation from nominal values, for Offset or Full Scale Span, as a percent of VFSS at 25°C.
7. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
8. Warm–up Time is defined as the time required for the device to meet the specified output voltage after the pressure has been stabilized.
MECHANICAL CHARACTERISTICS
Characteristics
Weight, Basic Element (Case 867)
Motorola Sensor Device Data
Typ
Unit
4.0
grams
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Freescale Semiconductor, Inc.
MPX5500 SERIES
Figure 3 illustrates the Differential/Gauge basic chip carrier
(Case 867). A fluorosilicone gel isolates the die surface and
wire bonds from the environment, while allowing the pressure signal to be transmitted to the sensor diaphragm. (For
use of the MPX5500D in a high pressure, cyclic application,
consult the factory.)
The MPX5500 series pressure sensor operating characteristics, and internal reliability and qualification tests are
based on use of dry air as the pressure media. Media, other
than dry air, may have adverse effects on sensor performance and long–term reliability. Contact the factory for
information regarding media compatibility in your application.
Figure 2 shows the sensor output signal relative to pressure input. Typical, minimum, and maximum output curves
are shown for operation over a temperature range of 0° to
85°C using the decoupling circuit shown in Figure 4. The
output will saturate outside of the specified pressure range.
Figure 4 shows the recommended decoupling circuit for
interfacing the output of the integrated sensor to the A/D input of a microprocessor or microcontroller. Proper decoupling of the power supply is recommended.
OUTPUT (V)
Freescale Semiconductor, Inc...
5.0
TRANSFER FUNCTION:
4.5 Vout = VS*(0.0018*P+0.04) ± ERROR
4.0 VS = 5.0 Vdc
TEMP = 0 to 85°C
3.5
3.0
TYPICAL
2.5
2.0
MAX
MIN
1.5
1.0
0.5
0
0
50
100 150 200 250 300 350 400
DIFFERENTIAL PRESSURE (kPa)
450
500
550
Figure 2. Output versus Pressure Differential
FLUORO SILICONE
DIE COAT
DIE
+5 V
STAINLESS STEEL
METAL COVER
ÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉ
P1
Vout
Vs
WIRE BOND
LEAD
FRAME
RTV DIE
BOND
P2
OUTPUT
IPS
m
1.0 F
m
0.01 F
GND
470 pF
EPOXY CASE
Figure 3. Cross–Sectional Diagram
(Not to Scale)
3–120
Figure 4. Recommended power supply decoupling
and output filtering.
For additional output filtering, please refer to
Application Note AN1646.
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPX5500 SERIES
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing fluorosilicone gel
which protects the die from the environment. The Motorola
Part Number
MPX pressure sensor is designed to operate with positive differential pressure applied, P1 > P2.
The Pressure (P1) side may be identified by using the Table
below:
Pressure (P1)
Side Identifier
Case Type
MPX5500D
867
Stainless Steel Cap
MPX5500DP
867C
Side with Part Marking
ORDERING INFORMATION
Freescale Semiconductor, Inc...
MPX Series
Device Name
Options
Case Type
Order Number
Device Marking
Basic Element
Differential
867
MPX5500D
MPX5500D
Ported Elements
Differential Dual Ports
867C
MPX5500DP
MPX5500DP
Motorola Sensor Device Data
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3–121
Freescale Semiconductor, Inc.
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Integrated Silicon Pressure Sensor
MPX5700
On-Chip Signal Conditioned,
SERIES
Temperature Compensated
and Calibrated
The MPX5700 series piezoresistive transducer is a state–of–the–art monolithic silicon
pressure sensor designed for a wide range of applications, but particularly those
employing a microcontroller or microprocessor with A/D inputs. This patented, single
element transducer combines advanced micromachining techniques, thin–film metallization, and bipolar processing to provide an accurate, high level analog output signal that
is proportional to the applied pressure.
INTEGRATED PRESSURE
SENSOR
0 to 700 kPa (0 to 101.5 psi)
15 to 700 kPa
(2.18 to 101.5 psi)
0.2 to 4.7 V OUTPUT
Freescale Semiconductor, Inc...
Features
• 2.5% Maximum Error over 0° to 85°C
• Ideally Suited for Microprocessor or Microcontroller–Based Systems
• Available in Absolute, Differential and Gauge Configurations
• Patented Silicon Shear Stress Strain Gauge
• Durable Epoxy Unibody Element
MPX5700D
CASE 867
VS
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
Vout
PINS 4, 5 AND 6 ARE NO CONNECTS
MPX5700DP
CASE 867C
GND
Figure 1. Fully Integrated Pressure Sensor Schematic
MPX5700AS
CASE 867E
PIN NUMBER
1
Vout
4
N/C
2
Gnd
5
N/C
3
VS
6
N/C
NOTE: Pins 4, 5, and 6 are internal
device connections. Do not connect
to external circuitry or ground. Pin 1
is noted by the notch in the lead.
REV 5
3–122
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPX5700 SERIES
MAXIMUM RATINGS(1)
Parametrics
Maximum Pressure(2) (P2
v 1 Atmosphere)
Storage Temperature
Symbol
Value
Unit
P1max
2800
kPa
Tstg
– 40 to +125
°C
TA
– 40 to +125
°C
Operating Temperature
NOTES:
1. Maximum Ratings apply to Case 867 only. Extended exposure at the specified limits may cause permanent damage or degradation to the
device.
2. This sensor is designed for applications where P1 is always greater than, or equal to P2. P2 maximum is 500 kPa.
OPERATING CHARACTERISTICS (VS = 5.0 Vdc, TA = 25°C unless otherwise noted, P1 > P2. Decoupling circuit shown in Figure 4
required to meet electrical specifications.)
Symbol
Min
Typ
Max
Unit
POP
0
15
—
700
700
kPa
Supply Voltage(2)
VS
4.75
5.0
5.25
Vdc
Supply Current
Io
–
7.0
10
mAdc
Voff
0.088
0.184
0.2
0.313
0.409
Vdc
Characteristic
Freescale Semiconductor, Inc...
Pressure Range(1)
Gauge, Differential: MPX5700D
Absolute: MPX5700A
Zero Pressure Offset(3)
Gauge, Differential:
Absolute
(0 to 85°C)
(0 to 85°C)
Full Scale Output(4)
(0 to 85°C)
VFSO
4.587
4.7
4.813
Vdc
Full Scale Span(5)
(0 to 85°C)
VFSS
—
4.5
—
Vdc
Accuracy(6)
(0 to 85°C)
—
—
—
± 2.5
%VFSS
V/P
—
6.4
—
mV/kPa
tR
—
1.0
—
ms
IO+
—
0.1
—
mAdc
—
—
20
—
ms
Sensitivity
Response Time(7)
Output Source Current at Full Scale Output
Warm–Up Time(8)
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range.
3. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
4. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
5. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
6. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation over the temperature range of 0° to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0° to 85°C, relative
to 25°C.
• Variation from Nominal: The variation from nominal values, for Offset or Full Scale Span, as a percent of VFSS, at 25°C.
7. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
8. Warm–up Time is defined as the time required for the device to meet the specified output voltage after the pressure has been stabilized.
MECHANICAL CHARACTERISTICS
Characteristics
Weight, Basic Element (Case 867)
Motorola Sensor Device Data
Typ
Unit
4.0
grams
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3–123
Freescale Semiconductor, Inc.
MPX5700 SERIES
ON–CHIP TEMPERATURE COMPENSATION, CALIBRATION AND SIGNAL CONDITIONING
Figure 3 illustrates the Differential/Gauge basic chip carrier (Case 867). A fluorosilicone gel isolates the die surface
and wire bonds from the environment, while allowing the
pressure signal to be transmitted to the sensor diaphragm.
(For use of the MPX5700D in a high pressure, cyclic application, consult the factory.)
The MPX5700 series pressure sensor operating characteristics, and internal reliability and qualification tests are based
on use of dry air as the pressure media. Media, other than dry
air, may have adverse effects on sensor performance and
long–term reliability. Contact the factory for information
regarding media compatibility in your application.
Figure 2 shows the sensor output signal relative to pressure input. Typical, minimum, and maximum output curves
are shown for operation over a temperature range of 0° to
85°C using the decoupling circuit shown in Figure 4. The
output will saturate outside of the specified pressure range.
Figure 4 shows the recommended decoupling circuit for
interfacing the output of the integrated sensor to the A/D input of a microprocessor or microcontroller. Proper decoupling of the power supply is recommended.
TRANSFER FUNCTION:
Vout = VS*(0.0012858*P+0.04) ± ERROR
4.0 VS = 5.0 Vdc
TEMP = 0 to 85°C
3.5
4.5
OUTPUT (V)
Freescale Semiconductor, Inc...
5.0
3.0
TYPICAL
2.5
2.0
MIN
MAX
1.5
1.0
0.5
0
0
100
300
500
200
400
600
DIFFERENTIAL PRESSURE (kPa)
700
800
Figure 2. Output versus Pressure Differential
FLUORO SILICONE
DIE COAT
+5 V
STAINLESS STEEL
METAL COVER
DIE
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
P1
WIRE BOND
LEAD
FRAME
RTV DIE
BOND
P2
Vout
OUTPUT
Vs
IPS
m
1.0 F
m
0.01 F
GND
470 pF
EPOXY CASE
Figure 3. Cross–Sectional Diagram
(Not to Scale)
3–124
Figure 4. Recommended power supply decoupling
and output filtering.
For additional output filtering, please refer to
Application Note AN1646.
For www.motorola.com/semiconductors
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPX5700 SERIES
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing fluoro silicone gel
which protects the die from harsh media. The Motorola MPX
Freescale Semiconductor, Inc...
Part Number
pressure sensor is designed to operate with positive differential pressure applied, P1 > P2.
The Pressure (P1) side may be identified by using the table
below:
Pressure (P1)
Side Identifier
Case Type
MPX5700D, MPX5700A
867C
Stainless Steel Cap
MPX5700DP
867C
Side with Part Marking
MPX5700GP, MPX5700AP
867B
Side with Port Attached
MPX5700GS, MPX5700AS
867E
Side with Port Attached
ORDERING INFORMATION
MPX Series
Device Type
Basic Element
Ported Elements
Options
Case Type
Order Number
Device Marking
Differential
867C
MPX5700D
MPX5700D
Absolute
867C
MPX5700A
MPX5700A
Differential Dual Ports
867C
MPX5700DP
MPX5700DP
Gauge
867B
MPX5700GP
MPX5700GP
Gauge, Axial
867E
MPX5700GS
MPX5700D
Absolute
867B
MPX5700AP
MPX5700AP
Absolute, Axial
867E
MPX5700AS
MPX5700A
Motorola Sensor Device Data
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Freescale Semiconductor, Inc.
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Integrated Silicon Pressure Sensor
On-Chip Signal Conditioned,
MPX5999D
Temperature Compensated
Freescale Semiconductor, Inc...
and Calibrated
The MPX5999D piezoresistive transducer is a state–of–the–art pressure sensor
designed for a wide range of applications, but particularly for those employing a
microcontroller or microprocessor with A/D inputs. This patented, single element
transducer combines advanced micromachining techniques, thin–film metallization and
bipolar semiconductor processing to provide an accurate, high level analog output signal
that is proportional to applied pressure.
Figure 1 shows a block diagram of the internal circuitry integrated on the stand–alone
sensing chip.
INTEGRATED PRESSURE
SENSOR
0 to 1000 kPa (0 to 150 psi)
0.2 to 4.7 V OUTPUT
Features
• Temperature Compensated Over 0 to 85°C
• Ideally Suited for Microprocessor or Microcontroller–Based Systems
• Patented Silicon Shear Stress Strain Gauge
• Durable Epoxy Unibody Element
MPX5999D
CASE 867
VS
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
PIN NUMBER
Vout
PINS 4, 5 AND 6 ARE NO CONNECTS
GND
Figure 1. Fully Integrated Pressure Sensor Schematic
1
Vout
4
N/C
2
Gnd
5
N/C
3
VS
6
N/C
NOTE: Pins 4, 5, and 6 are internal
device connections. Do not connect
to external circuitry or ground. Pin 1
is noted by the notch in the lead.
REV 4
3–126
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPX5999D
MAXIMUM RATINGS(1)
Parametrics
Maximum Pressure(2) (P1 > P2)
Storage Temperature
Operating Temperature
Symbol
Value
Unit
P1max
4000
kPa
Tstg
– 40° to +125
°C
TA
– 40° to +125
°C
NOTES:
1. Extended exposure at the specified limits may cause permanent damage or degradation to the device.
2. This sensor is designed for applications where P1 is always greater than, or equal to P2. P2 maximum is 500 kPa.
OPERATING CHARACTERISTICS (VS = 5.0 Vdc, TA = 25°C unless otherwise noted, P1 > P2. Decoupling circuit shown in Figure 4
required to meet electrical specifications.)
Freescale Semiconductor, Inc...
Characteristic
Symbol
Min
Typ
Max
Unit
Pressure Range(1)
POP
0
—
1000
kPa
Supply Voltage(2)
VS
4.75
5.0
5.25
Vdc
Supply Current
Io
—
7.0
10
mAdc
Zero Pressure Offset(3)
Voff
0.088
0.2
0.313
Vdc
Full Scale Output(4) (0 to 85°C)
(0 to 85°C)
VFSO
4.587
4.7
4.813
Vdc
Full Scale Span(5) (0 to 85°C)
VFSS
—
4.5
—
Vdc
V/P
—
4.5
—
mV/kPa
—
—
—
± 2.5
%VFSS
tR
—
1.0
—
ms
IO+
—
0.1
—
mA
—
—
20
—
ms
Sensitivity
Accuracy(6)
(0 to 85°C)
Response Time(7)
Output Source Current at Full Scale Output
Warm–Up Time(8)
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range.
3. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
4. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
5. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
6. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation over the temperature range of 0° to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0° to 85°C, relative
to 25°C.
• Variation from Nominal: The variation from nominal values, for Offset or Full Scale Span, as a percent of VFSS, at 25°C.
7. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
8. Warm–up Time is defined as the time required for the device to meet the specified output voltage after the pressure has been stabilized.
MECHANICAL CHARACTERISTICS
Characteristics
Weight, Basic Element (Case 867)
Motorola Sensor Device Data
Typ
Unit
4.0
grams
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Freescale Semiconductor, Inc.
MPX5999D
ON–CHIP TEMPERATURE COMPENSATION, CALIBRATION AND SIGNAL CONDITIONING
Figure 2 shows the sensor output signal relative to pressure input. Typical, minimum, and maximum output curves
are shown for operation over a temperature range of 0° to
85°C using the decoupling circuit shown in Figure 4. The
output will saturate outside of the specified pressure range.
The performance over temperature is achieved by integrating the shear–stress strain gauge, temperature compensation, calibration and signal conditioning circuitry onto a single
monolithic chip.
Figure 3 illustrates the differential or gauge configuration in the
basic chip carrier (Case 867). A fluoro silicone gel isolates the
die surface and wire bonds from harsh environments, while al-
lowing the pressure signal to be transmitted to the silicon diaphragm.
The MPX5999D pressure sensor operating characteristics,
and internal reliability and qualification tests are based on use
of dry air as the pressure media. Media other than dry air may
have adverse effects on sensor performance and long–term
reliability. Contact the factory for information regarding media
compatibility in your application.
Figure 4 shows the recommended decoupling circuit for
interfacing the output of the integrated sensor to the A/D input of a microprocessor or microcontroller. Proper decoupling of the power supply is recommended.
OUTPUT (V)
Freescale Semiconductor, Inc...
5.0
TRANSFER FUNCTION:
4.5 Vout = VS*(0.000901*P+0.04) ± ERROR
4.0 VS = 5.0 Vdc
TEMP = 0 to 85°C
3.5
3.0
TYPICAL
2.5
2.0
MAX
MIN
1.5
1.0
0.5
0
0
100
200 300 400 500 600 700 800
DIFFERENTIAL PRESSURE (kPa)
900 1000 1100
Figure 2. Output versus Pressure Differential
SILICONE
DIE COAT
+5 V
STAINLESS STEEL
METAL COVER
ÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉ
DIE
P1
Vout
LEAD
FRAME
RTV DIE
BOND
P2
THERMOPLASTIC CASE
Figure 3. Cross–Sectional Diagram
(Not to Scale)
3–128
OUTPUT
Vs
WIRE BOND
IPS
m
1.0 F
m
0.01 F
GND
470 pF
Figure 4. Recommended power supply decoupling
and output filtering.
For additional output filtering, please refer to
Application Note AN1646.
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPX5999D
PRESSURE (P1) / VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing fluoro silicone gel
which protects the die from harsh media. The Motorola MPX
Part Number
pressure sensor is designed to operate with positive differential pressure applied, P1 > P2.
The Pressure (P1) side may be identified by using the
table below:
Pressure (P1)
Side Identifier
Case Type
MPX5999D
867
Stainless Steel Cap
Freescale Semiconductor, Inc...
ORDERING INFORMATION
The MPX5999D pressure sensor is available as an element only.
MPX Series
Device Type
Basic Element
Options
Differential
Motorola Sensor Device Data
Case Type
867
Order Number
MPX5999D
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Information On This Product,
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Device Marking
MPX5999D
3–129
Freescale Semiconductor, Inc.
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
High Temperature Accuracy
MPXA6115A
Integrated Silicon Pressure Sensor
MPXH6115A
for Measuring Absolute Pressure,
SERIES
On-Chip Signal Conditioned,
Temperature Compensated
Freescale Semiconductor, Inc...
and Calibrated
INTEGRATED
PRESSURE SENSOR
15 to 115 kPa (2.2 to 16.7 psi)
0.2 to 4.8 Volts Output
Motorola’s MPXA6115A/MPXH6115A series sensor integrates on–chip, bipolar op amp
circuitry and thin film resistor networks to provide a high output signal and temperature
compensation. The small form factor and high reliability of on–chip integration make the
Motorola pressure sensor a logical and economical choice for the system designer.
The MPXA6115A/MPXH6115A series piezoresistive
transducer is a state–of–the–art, monolithic, signal
SUPER SMALL OUTLINE
conditioned, silicon pressure sensor. This sensor
PACKAGE
combines advanced micromachining techniques, thin
film metallization, and bipolar semiconductor processing
to provide an accurate, high level analog output signal
that is proportional to applied pressure.
Figure 1 shows a block diagram of the internal
circuitry integrated on a pressure sensor chip.
MPXH6115A6U
Features
• Improved Accuracy at High Temperature
• Available in Small and Super Small Outline
Packages
• 1.5% Maximum Error over 0° to 85°C
• Ideally suited for Microprocessor or
Microcontroller–Based Systems
• Temperature Compensated from – 40° to +125°C
• Durable Thermoplastic (PPS) Surface Mount
Package
Application Examples
• Aviation Altimeters
• Industrial Controls
• Engine Control/Manifold Absolute Pressure (MAP)
• Weather Station and Weather Reporting Device
Barometers
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
CASE 1317
MPXA6115A6U
CASE 482
MPXH6115AC6U
CASE 1317A
MPXA6115AC6U
CASE 482A
PIN NUMBER
PIN NUMBER
1
N/C
5
N/C
1
N/C
5
N/C
2
6
N/C
2
N/C
7
N/C
3
VS
Gnd
6
3
VS
Gnd
7
N/C
4
Vout
8
N/C
4
Vout
8
N/C
NOTE: Pins 1, 5, 6, 7, and 8 are
internal device connections. Do not
connect to external circuitry or
ground. Pin 1 is denoted by the
chamfered corner of the package.
VS
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
SMALL OUTLINE PACKAGE
NOTE: Pins 1, 5, 6, 7, and 8 are
internal device connections. Do not
connect to external circuitry or
ground. Pin 1 is denoted by the notch
in the lead.
Vout
PINS 1, 5, 6, 7 AND 8 ARE NO CONNECTS
GND
Figure 1. Fully Integrated Pressure Sensor
Schematic
REV 1
3–130
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Motorola Sensor Device Data
Freescale Semiconductor,
Inc.
MPXA6115A
MPXH6115A SERIES
MAXIMUM RATINGS(1)
Parametrics
Symbol
Value
Units
Pmax
400
kPa
Tstg
–40° to +125°
°C
Operating Temperature
TA
–40° to +125°
°C
Output Source Current @ Full Scale Output(2)
Io+
0.5
mAdc
Output Sink Current @ Minimum Pressure Offset(2)
Io–
–0.5
mAdc
Maximum Pressure (P1
u P2)
Storage Temperature
NOTES:
1. Exposure beyond the specified limits may cause permanent damage or degradation to the device.
2. Maximum Output Current is controlled by effective impedance from Vout to Gnd or Vout to VS in the application circuit.
OPERATING CHARACTERISTICS (VS = 5.0 Vdc, TA = 25°C unless otherwise noted, P1
Characteristic
Min
Typ
Max
Unit
POP
15
—
115
kPa
Supply Voltage(1)
VS
4.75
5.0
5.25
Vdc
Supply Current
Io
—
6.0
10
mAdc
Pressure Range
Freescale Semiconductor, Inc...
u P2.)
Symbol
Minimum Pressure Offset(2)
@ VS = 5.0 Volts
(0 to 85°C)
Voff
0.133
0.200
0.268
Vdc
Full Scale Output(3)
@ VS = 5.0 Volts
(0 to 85°C)
VFSO
4.633
4.700
4.768
Vdc
Full Scale Span(4)
@ VS = 5.0 Volts
(0 to 85°C)
VFSS
4.433
4.500
4.568
Vdc
Accuracy(5)
(0 to 85°C)
—
—
—
±1.5
%VFSS
Sensitivity
V/P
—
45.9
—
mV/kPa
Response Time(6)
tR
—
1.0
—
ms
Warm–Up Time(7)
—
—
20
—
ms
Offset Stability(8)
—
—
± 0.25
—
%VFSS
NOTES:
1. Device is ratiometric within this specified excitation range.
2. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
3. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
4. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
5. Accuracy is the deviation in actual output from nominal output over the entire pressure range and temperature range as a percent of span
at 25°C due to all sources of error including the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential
pressure applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from
minimum or maximum rated pressure at 25°C.
• TcSpan:
Output deviation over the temperature range of 0° to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum pressure applied, over the temperature range of 0° to 85°C, relative
to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Warm–up Time is defined as the time required for the product to meet the specified output voltage after the pressure has been stabilized.
8. Offset Stability is the product’s output deviation when subjected to 1000 cycles of Pulsed Pressure, Temperature Cycling with Bias Test.
Motorola Sensor Device Data
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Freescale Semiconductor, Inc.
MPXA6115A MPXH6115A SERIES
DIE
FLUORO SILICONE
GEL DIE COAT
+5.0 V
STAINLESS
STEEL CAP
P1
WIRE BOND
THERMOPLASTIC
CASE
LEAD
FRAME
VS Pin 2
MPXA6115A
MPXH6115A
Vout Pin 4
100 nF
to ADC
47 pF
GND Pin 3
51 K
ABSOLUTE ELEMENT
DIE BOND
SEALED VACUUM REFERENCE
Figure 2 illustrates the absolute sensing chip in the basic
Super Small Outline chip carrier (Case 1317).
Figure 3. Typical Application Circuit
(Output Source Current Operation)
Figure 3 shows a typical application circuit (output source
current operation).
5.0
4.5
4.0
OUTPUT (Volts)
3.5
MAX
TRANSFER FUNCTION:
Vout = Vs* (.009*P–.095) ± Error
VS = 5.0 Vdc
TEMP = 0 to 85°C
TYP
3.0
2.5
2.0
1.5
MIN
1.0
0.5
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
115
120
Freescale Semiconductor, Inc...
Figure 2. Cross Sectional Diagram SSOP
(not to scale)
Pressure (ref: to sealed vacuum) in kPa
Figure 4. Output versus Absolute Pressure
Figure 4 shows the sensor output signal relative to pressure input. Typical minimum and maximum output curves
are shown for operation over 0 to 85°C temperature range.
The output will saturate outside of the rated pressure range.
A fluorosilicone gel isolates the die surface and wire
bonds from the environment, while allowing the pressure
signal to be transmitted to the silicon diaphragm. The
3–132
MPXA6115A/MPXH6115A series pressure sensor operating
characteristics, internal reliability and qualification tests are
based on use of dry air as the pressure media. Media other
than dry air may have adverse effects on sensor performance and long–term reliability. Contact the factory for
information regarding media compatibility in your application.
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor,
Inc.
MPXA6115A
MPXH6115A SERIES
Transfer Function (MPXA6115A/MPXH6115A)
Nominal Transfer Value: Vout = VS x (0.009 x P – 0.095)
± (Pressure Error x Temp. Factor x 0.009 x VS)
VS = 5.0 ± 0.25 Vdc
Temperature Error Band
MPXA6115A/MPXH6115A Series
4.0
Break Points
Temp
3.0
Temperature
Error
Factor
Multiplier
– 40
0 to 85
125
2.0
3
1
1.75
1.0
–40
–20
0
20
40
60
80
100
120
140
Temperature in C°
NOTE: The Temperature Multiplier is a linear response from 0°C to –40°C and from 85°C to 125°C
Pressure Error Band
Error Limits for Pressure
3.0
2.0
Pressure Error (kPa)
Freescale Semiconductor, Inc...
0.0
1.0
0.0
20
40
60
80
100
120
Pressure (in kPa)
–1.0
– 2.0
– 3.0
Pressure
Error (Max)
15 to 115 (kPa)
± 1.5 (kPa)
ORDERING INFORMATION — SMALL OUTLINE PACKAGE
Device Type
Options
Case No.
Basic Element
Absolute, Element Only
482
MPXA6115A6U
Rails
MPXA6115A
Absolute, Element Only
482
MPXA6115A6T1
Tape and Reel
MPXA6115A
Absolute, Axial Port
482A
MPXA6115AC6U
Rails
MPXA6115A
Absolute, Axial Port
482A
MPXA6115AC6T1
Tape and Reel
MPXA6115A
Ported Element
MPX Series Order No.
Packing Options
Marking
ORDERING INFORMATION — SUPER SMALL OUTLINE PACKAGE
Device Type
Options
Case No.
Basic Element
Absolute, Element Only
1317
MPXH6115A6U
Rails
MPXH6115A
Absolute, Element Only
1317
MPXH6115A6T1
Tape and Reel
MPXH6115A
Absolute, Axial Port
1317A
MPXH6115AC6U
Rails
MPXH6115A
Absolute, Axial Port
1317A
MPXH6115AC6T1
Tape and Reel
MPXH6115A
Ported Element
Motorola Sensor Device Data
MPX Series Order No.
Packing Options
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Marking
3–133
Freescale Semiconductor, Inc.
MPXA6115A MPXH6115A SERIES
SURFACE MOUNTING INFORMATION
MINIMUM RECOMMENDED FOOTPRINT FOR SMALL AND SUPER SMALL PACKAGES
a solder reflow process. It is always recommended to fabricate boards with a solder mask layer to avoid bridging and/or
shorting between solder pads, especially on tight tolerances
and/or tight layouts.
Surface mount board layout is a critical portion of the total
design. The footprint for the semiconductor package must
be the correct size to ensure proper solder connection interface between the board and the package. With the correct
pad geometry, the packages will self–align when subjected to
0.100 TYP
2.54
0.660
16.76
Freescale Semiconductor, Inc...
0.060 TYP 8X
1.52
0.300
7.62
inch
mm
0.100 TYP 8X
2.54
Figure 5. SOP Footprint (Case 482)
0.050
1.27
TYP
0.387
9.83
0.150
3.81
0.027 TYP 8X
0.69
0.053 TYP 8X
1.35
inch
mm
Figure 6. SSOP Footprint (Case 1317 and 1317A)
3–134
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MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
Media Resistant, Integrated Silicon
Pressure Sensor for Manifold
MPXAZ4100A
SERIES
Absolute Pressure Applications
On-Chip Signal Conditioned,
Temperature Compensated, and
Freescale Semiconductor, Inc...
Calibrated
The Motorola MPXAZ4100A series Manifold Absolute Pressure (MAP) sensor for
engine control is designed to sense absolute air pressure within the intake manifold.
This measurement can be used to compute the amount of fuel required for each
cylinder. The small form factor and high reliability of on–chip integration makes the
Motorola MAP sensor a logical and economical choice for automotive system
designers.
The MPXAZ4100A series piezoresistive transducer is a state–of–the–art, monolithic,
signal conditioned, silicon pressure sensor. This sensor combines advanced
micromachining techniques, thin film metallization, and bipolar semiconductor
processing to provide an accurate, high level analog output signal that is proportional to
applied pressure.
Figure 1 shows a block diagram of the internal circuitry integrated on a pressure
sensor chip.
INTEGRATED
PRESSURE SENSOR
20 to 105 kPa (2.9 to 15.2 psi)
0.3 to 4.9 V Output
SMALL OUTLINE PACKAGE
MPXAZ4100AC6U
CASE 482A
Features
• Resistant to high humidity and common automotive media
• 1.8% Maximum Error Over 0° to 85°C
• Specifically Designed for Intake Manifold Absolute
Pressure Sensing in Engine Control Systems
• Ideally Suited for Microprocessor or Microcontroller Based Systems
• Temperature Compensated Over – 40°C to +125°C
MPXAZ4100A6U
CASE 482
• Durable Thermoplastic (PPS) Surface Mount Package
Application Examples
PIN NUMBER
• Manifold Sensing for Automotive Systems
• Also Ideal for Non–Automotive Applications
1
N/C
5
N/C
2
VS
Gnd
6
N/C
7
N/C
3
VS
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
N/C
Vout
8
NOTE: Pins 1, 5, 6, 7, and 8 are not
device connections. Do not connect to
external circuitry or ground. Pin 1 is
noted by the notch in the lead.
4
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
Vout
PINS 1, 5, 6, 7 AND 8 ARE NO CONNECTS
FOR SMALL OUTLINE PACKAGE DEVICE
GND
Figure 1. Fully Integrated Pressure Sensor Schematic
Rev 0
Motorola Sensor Device Data
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3–135
Freescale Semiconductor, Inc.
MPXAZ4100A SERIES
MAXIMUM RATINGS(NOTE)
Parametric
Maximum Pressure (P1 > P2)
Storage Temperature
Symbol
Value
Unit
Pmax
400
kPa
Tstg
– 40 to +125
°C
TA
– 40 to +125
°C
Operating Temperature
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 5.1 Vdc, TA = 25°C unless otherwise noted, P1 > P2. Decoupling circuit shown in Figure 3
required to meet electrical specifications.)
Freescale Semiconductor, Inc...
Characteristic
Symbol
Min
Typ
Max
Unit
Pressure Range(1)
POP
20
—
105
kPa
Supply Voltage(2)
VS
4.85
5.1
5.35
Vdc
Supply Current
Io
—
7.0
10
mAdc
Minimum Pressure Offset(3)
@ VS = 5.1 Volts
(0 to 85°C)
Voff
0.225
0.306
0.388
Vdc
Full Scale Output(4)
@ VS = 5.1 Volts
(0 to 85°C)
VFSO
4.870
4.951
5.032
Vdc
Full Scale Span(5)
@ VS = 5.1 Volts
(0 to 85°C)
VFSS
—
4.59
—
Vdc
Accuracy(6)
(0 to 85°C)
—
—
—
±1.8
%VFSS
Sensitivity
V/P
—
54
—
mV/kPa
Response Time(7)
tR
—
1.0
—
ms
Output Source Current at Full Scale Output
Io+
—
0.1
—
mAdc
Warm–Up Time(8)
—
—
20
—
ms
Offset Stability(9)
—
—
± 0.5
—
%VFSS
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range.
3. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
4. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
5. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
6. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation over the temperature range of 0 to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative to
25°C.
• Variation from Nominal: The variation from nominal values, for Offset or Full Scale Span, as a percent of VFSS, at 25°C.
7. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
8. Warm–up Time is defined as the time required for the product to meet the specified output voltage after the Pressure has been stabilized.
9. Offset Stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
3–136
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
FLUORO SILICONE
GEL DIE COAT
DIE
MPXAZ4100A SERIES
STAINLESS
STEEL CAP
P1
WIRE BOND
THERMOPLASTIC
CASE
LEAD
FRAME
ABSOLUTE ELEMENT
DIE BOND
Figure 2. Cross Sectional Diagram SOP
(not to scale)
Figure 2 illustrates an absolute sensing chip in the basic chip carrier (Case 482).
5.0
4.5
+5 V
4.0
Vout
OUTPUT
Vs
IPS
m
1.0 F
m
0.01 F
GND
OUTPUT (Volts)
3.5
3.0
TRANSFER FUNCTION:
Vout = Vs* (.01059*P–.152) ± Error
VS = 5.1 Vdc
TEMP = 0 to 85°C
20 kPa TO 105 kPa
MPXAZ4100A
MAX
TYP
2.5
2.0
1.5
470 pF
MIN
1.0
0.5
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
Freescale Semiconductor, Inc...
SEALED VACUUM REFERENCE
Pressure (ref: to sealed vacuum) in kPa
Figure 3. Recommended power supply decoupling
and output filtering.
For additional output filtering, please refer to
Application Note AN1646.
Figure 4 shows the sensor output signal relative to pressure input. Typical, minimum, and maximum output curves
are shown for operation over a temperature range of 0° to
85°C using the decoupling circuit shown in Figure 3. The
output will saturate outside of the specified pressure range.
A gel die coat isolates the die surface and wire bonds
from the environment, while allowing the pressure signal
to be transmitted to the sensor diaphragm. The gel die
coat and durable polymer package provide a media resis-
Motorola Sensor Device Data
Figure 4. Output versus Absolute Pressure
tant barrier that allows the sensor to operate reliably in
high humidity conditions as well as environments containing common automotive media. Contact the factory for
more information regarding media compatibility in your
specific application.
Figure 3 shows the recommended decoupling circuit for interfacing the output of the integrated sensor to the A/D input
of a microprocessor or microcontroller. Proper decoupling of
the power supply is recommended.
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–137
MPXAZ4100A SERIES
Freescale Semiconductor, Inc.
Transfer Function (MPXAZ4100A)
Nominal Transfer Value: Vout = VS (P x 0.01059 – 0.1518)
+/– (Pressure Error x Temp. Factor x 0.01059 x VS)
VS = 5.1 V ± 0.25 Vdc
Temperature Error Band
MPXAZ4100A Series
4.0
Temperature
Error
Factor
2.0
Temp
Multiplier
– 40
0 to 85
+125
3
1
3
1.0
0.0
–40
–20
0
20
40
60
80
100
120
140
Temperature in C°
NOTE: The Temperature Multiplier is a linear response from 0°C to –40°C and from 85°C to 125°C.
Pressure Error Band
Error Limits for Pressure
3.0
2.0
Pressure Error (kPa)
Freescale Semiconductor, Inc...
3.0
1.0
0.0
20
40
60
80
100
Pressure (in kPa)
120
–1.0
– 2.0
– 3.0
Pressure
Error (Max)
20 to 105 (kPa)
± 1.5 (kPa)
ORDERING INFORMATION — SMALL OUTLINE PACKAGE
Device Type
Options
Case No.
Basic Element
Absolute, Element Only
482
MPXAZ4100A6U
Rails
MPXAZ4100A
Absolute, Element Only
482
MPXAZ4100A6T1
Tape and Reel
MPXAZ4100A
Absolute, Axial Port
482A
MPXAZ4100AC6U
Rails
MPXAZ4100A
Absolute, Axial Port
482A
MPXAZ4100AC6T1
Tape and Reel
MPXAZ4100A
Ported Element
3–138
MPX Series Order No.
Packing Options
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Marking
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPXAZ4100A SERIES
INFORMATION FOR USING THE SMALL OUTLINE PACKAGE (CASE 482)
MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS
Surface mount board layout is a critical portion of the total
design. The footprint for the surface mount packages must
be the correct size to ensure proper solder connection interface between the board and the package. With the correct
fottprint, the packages will self align when subjected to a
solder reflow process. It is always recommended to design
boards with a solder mask layer to avoid bridging and shorting between solder pads.
0.100 TYP 8X
2.54
0.660
16.76
Freescale Semiconductor, Inc...
0.060 TYP 8X
1.52
0.300
7.62
0.100 TYP 8X
2.54
inch
mm
SCALE 2:1
Figure 5. SOP Footprint (Case 482)
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
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3–139
Freescale Semiconductor, Inc.
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Media Resistant, Integrated Silicon
Pressure Sensor for Manifold
MPXAZ4115A
SERIES
Absolute Pressure, Altimeter or
Barometer Applications
On-Chip Signal Conditioned,
Temperature Compensated, and
Freescale Semiconductor, Inc...
Calibrated
INTEGRATED
PRESSURE SENSOR
15 to 115 kPa (2.2 to 16.7 psi)
0.2 to 4.8 V Output
Motorola’s MPXAZ4115A series sensor integrates on–chip, bipolar op amp circuitry and
thin film resistor networks to provide a high output signal and temperature compensation.
The small form factor and high reliability of on–chip integration make the Motorola pressure
sensor a logical and economical choice for the system designer.
The MPXAZ4115A series piezoresistive transducer is a state–of–the–art, monolithic,
signal conditioned, silicon pressure sensor. This sensor combines advanced
micromachining techniques, thin film metallization, and bipolar semiconductor processing to
provide an accurate, high level analog output signal that is proportional to applied pressure.
Figure 1 shows a block diagram of the internal circuitry integrated on a pressure
sensor chip.
SMALL OUTLINE PACKAGE
MPXAZ4115AC6U
CASE 482A
Features
• Resistant to high humidity and common automotive media
• 1.5% Maximum Error over 0° to 85°C
• Ideally suited for Microprocessor or Microcontroller–
Based Systems
• Temperature Compensated from – 40° to +125°C
• Durable Thermoplastic (PPS) Surface Mount Package
Application Examples
MPXAZ4115A6U
CASE 482
• Aviation Altimeters
• Industrial Controls
• Engine Control
PIN NUMBER
• Weather Stations and Weather Reporting Devices
VS
1
N/C
5
N/C
2
VS
Gnd
6
N/C
7
N/C
3
N/C
Vout
8
NOTE: Pins 1, 5, 6, 7, and 8 are not
device connections. Do not connect to
external circuitry or ground. Pin 1 is
noted by the notch in the lead.
4
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
Vout
PINS 1, 5, 6, 7 AND 8 ARE NO CONNECTS
FOR SMALL OUTLINE PACKAGE DEVICE
GND
Figure 1. Fully Integrated Pressure Sensor Schematic
Rev 0
3–140
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More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPXAZ4115A SERIES
MAXIMUM RATINGS(NOTE)
Parametrics
Maximum Pressure (P1
u P2)
Storage Temperature
Symbol
Value
Units
Pmax
400
kPa
Tstg
–40° to +125°
°C
TA
–40° to +125°
°C
Operating Temperature
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 5.1 Vdc, TA = 25°C unless otherwise noted, P1
required to meet Electrical Specifications.)
Characteristic
Symbol
Min
Typ
Max
Unit
POP
15
—
115
kPa
Supply Voltage(1)
VS
4.85
5.1
5.35
Vdc
Supply Current
Io
—
7.0
10
mAdc
Pressure Range
Freescale Semiconductor, Inc...
u P2. Decoupling circuit shown in Figure 3
Minimum Pressure Offset(2)
@ VS = 5.1 Volts
(0 to 85°C)
Voff
0.135
0.204
0.273
Vdc
Full Scale Output(3)
@ VS = 5.1 Volts
(0 to 85°C)
VFSO
4.725
4.794
4.863
Vdc
Full Scale Span(4)
@ VS = 5.1 Volts
(0 to 85°C)
VFSS
4.521
4.590
4.659
Vdc
Accuracy(5)
(0 to 85°C)
—
—
—
±1.5
%VFSS
Sensitivity
V/P
—
45.9
—
mV/kPa
Response Time(6)
tR
—
1.0
—
ms
Output Source Current at Full Scale Output
Io+
—
0.1
—
mAdc
Warm–Up Time(7)
—
—
20
—
ms
Offset Stability(8)
—
—
± 0.5
—
%VFSS
NOTES:
1. Device is ratiometric within this specified excitation range.
2. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
3. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
4. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
5. Accuracy is the deviation in actual output from nominal output over the entire pressure range and temperature range as a percent of span
at 25°C due to all sources of error including the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential
pressure applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from
minimum or maximum rated pressure at 25°C.
• TcSpan:
Output deviation over the temperature range of 0° to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum pressure applied, over the temperature range of 0° to 85°C, relative
to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Warm–up Time is defined as the time required for the product to meet the specified output voltage after the pressure has been stabilized.
8. Offset Stability is the product’s output deviation when subjected to 1000 cycles of Pulsed Pressure, Temperature Cycling with Bias Test.
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–141
Freescale Semiconductor, Inc.
MPXAZ4115A SERIES
FLUORO SILICONE
GEL DIE COAT
+5 V
DIE
STAINLESS
STEEL CAP
Vout
P1
Vs
WIRE BOND
THERMOPLASTIC
CASE
LEAD
FRAME
IPS
m
1.0 F
ABSOLUTE ELEMENT
m
GND
0.01 F
470 pF
DIE BOND
Figure 3. Recommended power supply decoupling
and output filtering.
For additional output filtering, please refer to
Application Note AN1646.
SEALED VACUUM REFERENCE
Figure 2. Cross Sectional Diagram SOP
(not to scale)
Figure 2 illustrates the absolute sensing chip in the basic
chip carrier (Case 482).
Figure 3 shows the recommended decoupling circuit for
interfacing the output of the integrated sensor to the A/D input of a microprocessor or microcontroller. Proper decoupling of the power supply is recommended.
5.0
4.5
4.0
OUTPUT (Volts)
3.5
MAX
TRANSFER FUNCTION:
Vout = Vs* (.009*P–.095) ± Error
VS = 5.1 Vdc
TEMP = 0 to 85°C
TYP
3.0
2.5
2.0
1.5
MIN
1.0
0.5
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
115
120
Freescale Semiconductor, Inc...
OUTPUT
Pressure (ref: to sealed vacuum) in kPa
Figure 4. Output versus Absolute Pressure
Figure 4 shows the sensor output signal relative to pressure input. Typical minimum and maximum output curves
are shown for operation over a temperature range of 0 to
85°C using the decoupling circuit shown in Figure 3. The
output will saturate outside of the specified pressure range.
A gel die coat isolates the die surface and wire bonds
from the environment, while allowing the pressure signal
3–142
to be transmitted to the sensor diaphragm. The gel die
coat and durable polymer package provide a media resistant barrier that allows the sensor to operate reliably in
high humidity conditions as well as environments containing common automotive media. Contact the factory for
more information regarding media compatibility in your
specific application.
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPXAZ4115A SERIES
Transfer Function (MPXAZ4115A)
Nominal Transfer Value: Vout = VS x (0.009 x P – 0.095)
± (Pressure Error x Temp. Factor x 0.009 x VS)
VS = 5.1 ± 0.25 Vdc
Temperature Error Band
MPXAZ4115A Series
4.0
Break Points
3.0
Temperature
Error
Factor
2.0
Temp
Multiplier
– 40
0 to 85
125
3
1
3
1.0
–40
–20
0
20
40
60
80
100
120
140
Temperature in C°
NOTE: The Temperature Multiplier is a linear response from 0°C to –40°C and from 85°C to 125°C
Pressure Error Band
Error Limits for Pressure
3.0
2.0
Pressure Error (kPa)
Freescale Semiconductor, Inc...
0.0
1.0
0.0
20
40
60
80
100
120
Pressure (in kPa)
–1.0
– 2.0
– 3.0
Pressure
Error (Max)
15 to 115 (kPa)
± 1.5 (kPa)
ORDERING INFORMATION — SMALL OUTLINE PACKAGE
Device Type
Options
Case No.
Basic Element
Absolute, Element Only
482
MPXAZ4115A6U
Rails
MPXAZ4115A
Absolute, Element Only
482
MPXAZ4115A6T1
Tape and Reel
MPXAZ4115A
Absolute, Axial Port
482A
MPXAZ4115AC6U
Rails
MPXAZ4115A
Absolute, Axial Port
482A
MPXAZ4115AC6T1
Tape and Reel
MPXAZ4115A
Ported Element
Motorola Sensor Device Data
MPX Series Order No.
Packing Options
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
Marking
3–143
MPXAZ4115A SERIES
Freescale Semiconductor, Inc.
INFORMATION FOR USING THE SMALL OUTLINE PACKAGE (CASE 482)
MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS
Surface mount board layout is a critical portion of the total
design. The footprint for the surface mount packages must
be the correct size to ensure proper solder connection interface between the board and the package. With the correct
fottprint, the packages will self–align when subjected to a
solder reflow process. It is always recommended to design
boards with a solder mask layer to avoid bridging and shorting between solder pads.
0.100 TYP 8X
2.54
0.660
16.76
Freescale Semiconductor, Inc...
0.060 TYP 8X
1.52
0.300
7.62
0.100 TYP 8X
2.54
inch
mm
SCALE 2:1
Figure 5. SOP Footprint (Case 482)
3–144
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
Media Resistant and
High Temperature Accuracy
MPXAZ6115A
SERIES
Integrated Silicon Pressure Sensor
for Measuring Absolute Pressure,
On-Chip Signal Conditioned,
Temperature Compensated
Freescale Semiconductor, Inc...
and Calibrated
INTEGRATED
PRESSURE SENSOR
15 to 115 kPa (2.2 to 16.7 psi)
0.2 to 4.8 Volts Output
Motorola’s MPXAZ6115A series sensor integrates on–chip, bipolar op amp circuitry
and thin film resistor networks to provide a high output signal and temperature
compensation. The small form factor and high reliability of on–chip integration make the
Motorola pressure sensor a logical and economical choice for the system designer.
The MPXAZ6115A series piezoresistive transducer is a state–of–the–art, monolithic,
signal conditioned, silicon pressure sensor. This sensor combines advanced
micromachining techniques, thin film metallization, and bipolar semiconductor processing
to provide an accurate, high level analog output signal that is proportional to applied
pressure.
Figure 1 shows a block diagram of the internal circuitry integrated on a pressure
sensor chip.
SMALL OUTLINE PACKAGE
MPXAZ6115A6U
CASE 482
Features
• Resistant to High Humidity and Common Automotive Media
• Improved Accuracy at High Temperature
• 1.5% Maximum Error over 0° to 85°C
• Ideally suited for Microprocessor or Microcontroller–Based Systems
• Temperature Compensated from – 40° to +125°C
• Durable Thermoplastic (PPS) Surface Mount Package
MPXAZ6115AC6U
CASE 482A
Application Examples
• Aviation Altimeters
PIN NUMBER
• Industrial Controls
• Engine Control/Manifold Absolute Pressure (MAP)
• Weather Station and Weather Reporting Devices
VS
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
1
N/C
5
N/C
2
6
N/C
3
VS
Gnd
7
N/C
4
Vout
8
N/C
NOTE: Pins 1, 5, 6, 7, and 8 are internal
device connections. Do not connect to
external circuitry or ground. Pin 1 is
denoted by the notch in the lead.
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
Vout
PINS 1, 5, 6, 7 AND 8 ARE NO CONNECTS
GND
Figure 1. Fully Integrated Pressure Sensor
Schematic
REV 0
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–145
MPXAZ6115A SERIES
Freescale Semiconductor, Inc.
MAXIMUM RATINGS(1)
Parametrics
Symbol
Value
Units
Pmax
400
kPa
Tstg
–40° to +125°
°C
Operating Temperature
TA
–40° to +125°
°C
Output Source Current @ Full Scale Output(2)
Io+
0.5
mAdc
Output Sink Current @ Minimum Pressure Offset(2)
Io–
–0.5
mAdc
Maximum Pressure (P1
u P2)
Storage Temperature
NOTES:
1. Exposure beyond the specified limits may cause permanent damage or degradation to the device.
2. Maximum Output Current is controlled by effective impedance from Vout to Gnd or Vout to VS in the application circuit.
OPERATING CHARACTERISTICS (VS = 5.0 Vdc, TA = 25°C unless otherwise noted, P1
Characteristic
Min
Typ
Max
Unit
POP
15
—
115
kPa
Supply Voltage(1)
VS
4.75
5.0
5.25
Vdc
Supply Current
Io
—
6.0
10
mAdc
Pressure Range
Freescale Semiconductor, Inc...
u P2.)
Symbol
Minimum Pressure Offset(2)
@ VS = 5.0 Volts
(0 to 85°C)
Voff
0.133
0.200
0.268
Vdc
Full Scale Output(3)
@ VS = 5.0 Volts
(0 to 85°C)
VFSO
4.633
4.700
4.768
Vdc
Full Scale Span(4)
@ VS = 5.0 Volts
(0 to 85°C)
VFSS
4.433
4.500
4.568
Vdc
Accuracy(5)
(0 to 85°C)
—
—
—
±1.5
%VFSS
Sensitivity
V/P
—
45.9
—
mV/kPa
Response Time(6)
tR
—
1.0
—
ms
Warm–Up Time(7)
—
—
20
—
ms
Offset Stability(8)
—
—
± 0.25
—
%VFSS
NOTES:
1. Device is ratiometric within this specified excitation range.
2. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
3. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
4. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
5. Accuracy is the deviation in actual output from nominal output over the entire pressure range and temperature range as a percent of span
at 25°C due to all sources of error including the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential
pressure applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from
minimum or maximum rated pressure at 25°C.
• TcSpan:
Output deviation over the temperature range of 0° to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum pressure applied, over the temperature range of 0° to 85°C, relative
to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Warm–up Time is defined as the time required for the product to meet the specified output voltage after the pressure has been stabilized.
8. Offset Stability is the product’s output deviation when subjected to 1000 cycles of Pulsed Pressure, Temperature Cycling with Bias Test.
3–146
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
FLUORO SILICONE
GEL DIE COAT
DIE
MPXAZ6115A SERIES
STAINLESS
STEEL CAP
P1
WIRE BOND
THERMOPLASTIC
CASE
LEAD
FRAME
+5.0 V
ABSOLUTE ELEMENT
VS Pin 2
DIE BOND
MPXAZ6115A
SEALED VACUUM REFERENCE
100 nF
Vout Pin 4
to ADC
47 pF
GND Pin 3
51 K
Figure 3. Typical Application Circuit
(Output Source Current Operation)
Figure 2 illustrates the absolute sensing chip in the basic
Small Outline chip carrier (Case 482).
Figure 3 shows a typical application circuit (output source
current operation).
5.0
4.5
4.0
OUTPUT (Volts)
3.5
MAX
TRANSFER FUNCTION:
Vout = Vs* (.009*P–.095) ± Error
VS = 5.0 Vdc
TEMP = 0 to 85°C
TYP
3.0
2.5
2.0
1.5
MIN
1.0
0.5
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
115
120
Freescale Semiconductor, Inc...
Figure 2. Cross Sectional Diagram SOP
(Not to Scale)
Pressure (ref: to sealed vacuum) in kPa
Figure 4. Output versus Absolute Pressure
Figure 4 shows the sensor output signal relative to pressure input. Typical minimum and maximum output curves
are shown for operation over 0 to 85°C temperature range.
The output will saturate outside of the rated pressure range.
A gel die coat isolates the die surface and wire bonds
from the environment, while allowing the pressure signal
to be transmitted to the sensor diaphragm. The gel die
Motorola Sensor Device Data
coat and durable polymer package provide a media resistant barrier that allows the sensor to operate reliably in
high humidity conditions as well as environments containing common automotive media. Contact the factory for
more information regarding media compatibility in your
specific application.
www.motorola.com/semiconductors
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Information On This Product,
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3–147
MPXAZ6115A SERIES
Freescale Semiconductor, Inc.
Transfer Function (MPXAZ6115A)
Nominal Transfer Value: Vout = VS x (0.009 x P – 0.095)
± (Pressure Error x Temp. Factor x 0.009 x VS)
VS = 5.0 ± 0.25 Vdc
Temperature Error Band
MPXAZ6115A Series
4.0
Break Points
Temp
3.0
Temperature
Error
Factor
Multiplier
– 40
0 to 85
125
2.0
3
1
1.75
1.0
–40
–20
0
20
40
60
80
100
120
140
Temperature in C°
NOTE: The Temperature Multiplier is a linear response from 0°C to –40°C and from 85°C to 125°C
Pressure Error Band
Error Limits for Pressure
3.0
2.0
Pressure Error (kPa)
Freescale Semiconductor, Inc...
0.0
1.0
0.0
20
40
60
80
100
120
Pressure (in kPa)
–1.0
– 2.0
– 3.0
Pressure
Error (Max)
15 to 115 (kPa)
± 1.5 (kPa)
ORDERING INFORMATION — SMALL OUTLINE PACKAGE
Device Type
Options
Case No.
Basic Element
Absolute, Element Only
482
MPXAZ6115A6U
Rails
MPXAZ6115A
Absolute, Element Only
482
MPXAZ6115A6T1
Tape and Reel
MPXAZ6115A
Absolute, Axial Port
482A
MPXAZ6115AC6U
Rails
MPXAZ6115A
Absolute, Axial Port
482A
MPXAZ6115AC6T1
Tape and Reel
MPXAZ6115A
Ported Element
3–148
MPX Series Order No.
Packing Options
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More Information On This Product,
Go to: www.freescale.com
Marking
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPXAZ6115A SERIES
SURFACE MOUNTING INFORMATION
MINIMUM RECOMMENDED FOOTPRINT FOR SMALL OUTLINE PACKAGE
Surface mount board layout is a critical portion of the total
design. The footprint for the semiconductor package must
be the correct size to ensure proper solder connection interface between the board and the package. With the correct
pad geometry, the packages will self–align when subjected to
a solder reflow process. It is always recommended to fabricate boards with a solder mask layer to avoid bridging and/or
shorting between solder pads, especially on tight tolerances
and/or tight layouts.
0.100 TYP
2.54
Freescale Semiconductor, Inc...
0.660
16.76
0.060 TYP 8X
1.52
0.300
7.62
0.100 TYP 8X
2.54
inch
mm
Figure 5. SOP Footprint (Case 482 and 482A)
Motorola Sensor Device Data
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Information On This Product,
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3–149
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
High Volume Sensor for
Low Pressure Applications
Motorola has developed a low cost, high volume, miniature pressure sensor package
which is ideal as a sub–module component or a disposable unit. The unique concept of
the Chip Pak allows great flexibility in system design while allowing an economic solution
for the designer. This new chip carrier package uses Motorola’s unique sensor die with its
piezoresistive technology, along with the added feature of on–chip, thin–film temperature
compensation and calibration.
NOTE: Motorola is also offering the Chip Pak package in application–specific
configurations, which will have an “SPX” prefix, followed by a four–digit number, unique
to the specific customer.
MPXC2011DT1
MPXC2012DT1
Motorola Preferred Device
PRESSURE SENSORS
0 to 75 mmHg (0 to 10 kPa)
Freescale Semiconductor, Inc...
Features:
• Low Cost
CHIP PAK PACKAGE
• Integrated Temperature Compensation and Calibration
• Ratiometric to Supply Voltage
• Polysulfone Case Material (Medical, Class V Approved)
• Provided in Easy–to–Use Tape and Reel
MPXC2011DT1/MPXC2012DT1
CASE 423A
Application Examples
• Respiratory Diagnostics
• Air Movement Control
• Controllers
PIN NUMBER
• Pressure Switching
1
Gnd
3
VS
NOTE: The die and wire bonds are exposed on the front side of the Chip Pak
(pressure is applied to the backside of the device). Front side die and wire protection
must be provided in the customer’s housing. Use caution when handling the devices
during all processes.
2
S+
4
S–
Motorola’s MPXC2011DT1/MPXC2012DT1 Pressure
Sensor has been designed for medical usage by combining
the performance of Motorola’s shear stress pressure sensor
design and the use of biomedically approved materials.
Materials with a proven history in medical situations have
been chosen to provide a sensor that can be used with
confidence in applications, such as invasive blood pressure
monitoring. It can be sterilized using ethylene oxide. The
portions of the pressure sensor that are required to be
biomedically approved are the rigid housing and the gel
coating.
The rigid housing is molded from a white, medical grade
polysulfone that has passed extensive biological testing
including: tissue culture test, rabbit implant, hemolysis,
intracutaneous test in rabbits, and system toxicity, USP.
The MPXC2011DT1 contains a silicone dielectric gel
which covers the silicon piezoresistive sensing element. The
gel is a nontoxic, nonallergenic elastomer system which
meets all USP XX Biological Testing Class V requirements.
The properties of the gel allow it to transmit pressure uniformly to the diaphragm surface, while isolating the internal
electrical connections from the corrosive effects of fluids,
such as saline solution. The gel provides electrical isolation
sufficient to withstand defibrillation testing, as specified in the
proposed Association for the Advancement of Medical
Instrumentation (AAMI) Standard for blood pressure transducers. A biomedically approved opaque filler in the gel prevents bright operating room lights from affecting the
performance of the sensor.
The MPXC2012DT1 is a no–gel option.
Preferred devices are Motorola recommended choices for future use and best overall value.
REV 2
3–150
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPXC2011DT1 MPXC2012DT1
MAXIMUM RATINGS(NOTE)
Rating
Maximum Pressure (Backside)
Storage Temperature
Operating Temperature
Symbol
Value
Unit
Pmax
75
kPa
Tstg
– 25 to +85
°C
TA
+15 to +40
°C
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 10 Vdc, TA = 25°C unless otherwise noted, P1 > P2)
Characteristic
Symbol
Min
Typ
Max
Unit
Pressure Range(1)
POP
0
—
10
kPa
Supply Voltage(2)
VS
—
3
10
Vdc
Supply Current
Io
—
6.0
—
mAdc
VFSS
24
25
26
mV
Voff
–1.0
—
1.0
mV
Sensitivity
∆V/∆P
—
2.5
—
mV/kPa
Linearity(5)
—
–1.0
—
1.0
%VFSS
Pressure Hysteresis(5) (0 to 10 kPa)
—
—
± 0.1
—
%VFSS
Full Scale Span(3)
Freescale Semiconductor, Inc...
Offset(4)
Temperature Hysteresis(5) (+15°C to +40°C)
Temperature Effect on Full Scale Span(5)
Temperature Effect on Offset(5)
Input Impedance
—
—
± 0.1
—
%VFSS
TCVFSS
–1.0
—
1.0
%VFSS
TCVoff
–1.0
—
1.0
mV
Zin
1300
—
2550
Ω
Zout
1400
—
3000
Ω
Response Time(6) (10% to 90%)
tR
—
1.0
—
ms
Warm–Up
—
—
20
—
ms
Offset Stability(7)
—
—
± 0.5
—
%VFSS
Output Impedance
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range. Operating the device above the specified excitation range may induce additional
error due to device self–heating.
3. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
4. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
5. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure, using end point method, over the specified
pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation at full rated pressure over the temperature range of 0 to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative
to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Offset stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
Motorola Sensor Device Data
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Information On This Product,
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3–151
Freescale Semiconductor, Inc.
MPXC2011DT1 MPXC2012DT1
ORDERING INFORMATION
The MPXC2011DT1/MPXC2012DT1 silicon pressure sensors are available in tape and reel.
Device Type/Order No.
Case No.
Device Description
Marking
MPXC2011DT1
423A
Chip Pak, 1/3 Gel
Date Code, Lot ID
MPXC2012DT1
423A
Chip Pak, No Gel
Date Code, Lot ID
Packaging Information
Tape Width
Quantity
330 mm
24 mm
1000 pc/reel
Freescale Semiconductor, Inc...
Tape and Reel
Reel Size
3–152
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Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
High Temperature Accuracy
Integrated Silicon Pressure Sensor
MPXH6300A
SERIES
for Measuring Absolute Pressure,
On-Chip Signal Conditioned,
Temperature Compensated
Freescale Semiconductor, Inc...
and Calibrated
Motorola’s MPXH6300A series sensor integrates on–chip, bipolar op amp circuitry and
thin film resistor networks to provide a high output signal and temperature compensation.
The small form factor and high reliability of on–chip integration make the Motorola pressure
sensor a logical and economical choice for the system designer.
The MPXH6300A series piezoresistive transducer is a state–of–the–art, monolithic,
signal conditioned, silicon pressure sensor. This sensor combines advanced
micromachining techniques, thin film metallization, and bipolar semiconductor processing to
provide an accurate, high level analog output signal that is proportional to applied pressure.
Figure 1 shows a block diagram of the internal circuitry integrated on a pressure
sensor chip.
INTEGRATED
PRESSURE SENSOR
20 to 304 kPa (3.0 to 42 psi)
0.3 to 4.9 Volts Output
SUPER SMALL OUTLINE
PACKAGE
Features
• Improved Accuracy at High Temperature
MPXH6300A6T1
CASE 1317
• Available in Small and Super Small Outline Packages
• 1.5% Maximum Error over 0° to 85°C
• Ideally suited for Microprocessor or Microcontroller–Based Systems
• Temperature Compensated from – 40° to +125°C
• Durable Thermoplastic (PPS) Surface Mount Package
Application Examples
• Aviation Altimeters
MPXH6300AC6T1
CASE 1317A
• Industrial Controls
• Engine Control/Manifold Absolute Pressure (MAP)
PIN NUMBER
• Weather Station and Weather Reporting Device Barometers
VS
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
Vout
1
N/C
5
N/C
2
6
N/C
3
VS
Gnd
7
N/C
4
Vout
8
N/C
NOTE: Pins 1, 5, 6, 7, and 8 are
internal device connections. Do not
connect to external circuitry or
ground. Pin 1 is denoted by the
chamfered corner of the package.
PINS 1, 5, 6, 7 AND 8 ARE NO CONNECTS
GND
Figure 1. Fully Integrated Pressure Sensor
Schematic
REV 0
Motorola Sensor Device Data
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MPXH6300A SERIES
Freescale Semiconductor, Inc.
MAXIMUM RATINGS(1)
Parametrics
Symbol
Value
Units
Pmax
1200
kPa
Tstg
–40° to +125°
°C
Operating Temperature
TA
–40° to +125°
°C
Output Source Current @ Full Scale Output(2)
Io+
0.5
mAdc
Output Sink Current @ Minimum Pressure Offset(2)
Io–
–0.5
mAdc
Maximum Pressure (P1
u P2)
Storage Temperature
NOTES:
1. Exposure beyond the specified limits may cause permanent damage or degradation to the device.
2. Maximum Output Current is controlled by effective impedance from Vout to Gnd or Vout to VS in the application circuit.
OPERATING CHARACTERISTICS (VS = 5.1 Vdc, TA = 25°C unless otherwise noted, P1
Characteristic
Min
Typ
Max
Unit
POP
20
—
304
kPa
Supply Voltage(1)
VS
4.74
5.1
5.46
Vdc
Supply Current
Io
—
6.0
10
mAdc
Pressure Range
Freescale Semiconductor, Inc...
u P2.)
Symbol
Minimum Pressure Offset(2)
@ VS = 5.1 Volts
(0 to 85°C)
Voff
0.241
0.306
0.371
Vdc
Full Scale Output(3)
@ VS = 5.1 Volts
(0 to 85°C)
VFSO
4.847
4.912
4.977
Vdc
Full Scale Span(4)
@ VS = 5.1 Volts
(0 to 85°C)
VFSS
4.476
4.606
4.736
Vdc
Accuracy(5)
(0 to 85°C)
—
—
—
±1.5
%VFSS
Sensitivity
V/P
—
16.2
—
mV/kPa
Response Time(6)
tR
—
1.0
—
ms
Warm–Up Time(7)
—
—
20
—
ms
Offset Stability(8)
—
—
± 0.25
—
%VFSS
NOTES:
1. Device is ratiometric within this specified excitation range.
2. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
3. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
4. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
5. Accuracy is the deviation in actual output from nominal output over the entire pressure range and temperature range as a percent of span
at 25°C due to all sources of error including the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential
pressure applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from
minimum or maximum rated pressure at 25°C.
• TcSpan:
Output deviation over the temperature range of 0° to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum pressure applied, over the temperature range of 0° to 85°C, relative
to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Warm–up Time is defined as the time required for the product to meet the specified output voltage after the pressure has been stabilized.
8. Offset Stability is the product’s output deviation when subjected to 1000 cycles of Pulsed Pressure, Temperature Cycling with Bias Test.
3–154
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
DIE
FLUORO SILICONE
GEL DIE COAT
+5.1 V
STAINLESS
STEEL CAP
MPXH6300A SERIES
P1
WIRE BOND
THERMOPLASTIC
CASE
LEAD
FRAME
VS Pin 2
MPXH6300A
Vout Pin 4
100 nF
GND Pin 3
to ADC
47 pF
51 K
ABSOLUTE ELEMENT
DIE BOND
SEALED VACUUM REFERENCE
Figure 3. Typical Application Circuit
(Output Source Current Operation)
Figure 2 illustrates the absolute sensing chip in the basic
Super Small Outline chip carrier (Case 1317).
Figure 3 shows a typical application circuit (output source
current operation).
5.0
4.5
4.0
OUTPUT (Volts)
3.5
TRANSFER FUNCTION:
Vout = Vs* (.00318*P–.00353) ± Error
VS = 5.1 Vdc
TEMP = 0 to 85°C
3.0
2.5
MAX
2.0
TYP
1.5
1.0
0.5
0
MIN
20
35
50
65
80
95
110
125
140
155
170
185
200
215
230
245
260
275
290
305
Freescale Semiconductor, Inc...
Figure 2. Cross Sectional Diagram SSOP
(not to scale)
Pressure (ref: to sealed vacuum) in kPa
Figure 4. Output versus Absolute Pressure
Figure 4 shows the sensor output signal relative to pressure input. Typical minimum and maximum output curves
are shown for operation over 0 to 85°C temperature range.
The output will saturate outside of the rated pressure range.
A fluorosilicone gel isolates the die surface and wire
bonds from the environment, while allowing the pressure
signal to be transmitted to the silicon diaphragm. The
Motorola Sensor Device Data
MPXH6300A series pressure sensor operating characteristics, internal reliability and qualification tests are based on
use of dry air as the pressure media. Media other than dry
air may have adverse effects on sensor performance and
long–term reliability. Contact the factory for information regarding media compatibility in your application.
www.motorola.com/semiconductors
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3–155
Freescale Semiconductor, Inc.
MPXH6300A SERIES
Transfer Function (MPXH6300A)
Nominal Transfer Value: Vout = VS x (0.00318 x P – 0.00353)
± (Pressure Error x Temp. Factor x 0.00318 x VS)
VS = 5.1 ± 0.36 Vdc
Temperature Error Band
MPXH6300A Series
4.0
Break Points
3.0
Temperature
Error
Factor
2.0
Temp
Multiplier
– 40
0 to 85
125
3
1
3
1.0
–40
–20
0
20
40
60
80
100
120
140
Temperature in C°
NOTE: The Temperature Multiplier is a linear response from 0°C to –40°C and from 85°C to 125°C
Pressure Error Band
Error Limits for Pressure
4.0
3.0
Pressure Error (kPa)
Freescale Semiconductor, Inc...
0.0
2.0
1.0
0.0
–1.0
60
20
100
140
180
220
260
Pressure (in kPa)
300
– 2.0
– 3.0
–4.0
Pressure
Error (Max)
20 to 304 (kPa)
± 4.0 (kPa)
ORDERING INFORMATION — SUPER SMALL OUTLINE PACKAGE
Device Type
Options
Case No.
Basic Element
Absolute, Element Only
1317
MPXH6300A6U
Rails
MPXH6300A
Absolute, Element Only
1317
MPXH6300A6T1
Tape and Reel
MPXH6300A
Absolute, Axial Port
1317A
MPXH6300AC6U
Rails
MPXH6300A
Absolute, Axial Port
1317A
MPXH6300AC6T1
Tape and Reel
MPXH6300A
Ported Element
3–156
MPX Series Order No.
Packing Options
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Marking
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPXH6300A SERIES
SURFACE MOUNTING INFORMATION
MINIMUM RECOMMENDED FOOTPRINT FOR SUPER SMALL OUTLINE PACKAGES
Surface mount board layout is a critical portion of the total
design. The footprint for the semiconductor package must
be the correct size to ensure proper solder connection interface between the board and the package. With the correct
pad geometry, the packages will self–align when subjected to
0.050
1.27
TYP
a solder reflow process. It is always recommended to fabricate boards with a solder mask layer to avoid bridging and/or
shorting between solder pads, especially on tight tolerances
and/or tight layouts.
0.387
9.83
Freescale Semiconductor, Inc...
0.150
3.81
0.027 TYP 8X
0.69
0.053 TYP 8X
1.35
inch
mm
Figure 5. SSOP Footprint (Case 1317 and 1317A)
Motorola Sensor Device Data
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3–157
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
10 kPa
On-Chip Temperature
Compensated & Calibrated
Silicon Pressure Sensors
MPXM2010
SERIES
The MPXM2010 device is a silicon piezoresistive pressure sensors providing a highly
accurate and linear voltage output — directly proportional to the applied pressure. The
sensor is a single, monolithic silicon diaphragm with the strain gauge and a thin–film
resistor network integrated on–chip. The chip is laser trimmed for precise span and offset
calibration and temperature compensation.
Motorola Preferred Device
0 to 10 kPa (0 to 1.45 psi)
25 mV FULL SCALE SPAN
(TYPICAL)
Features
Freescale Semiconductor, Inc...
• Temperature Compensated Over 0°C to + 85°C
• Available in Easy–to–Use Tape & Reel
MPAK PACKAGE
• Ratiometric to Supply Voltage
• Gauge Ported & Non Ported Options
Application Examples
• Respiratory Diagnostics
SCALE 1:1
• Air Movement Control
MPXM2010D/DT1
CASE 1320
• Controllers
• Pressure Switching
Figure 1 shows a block diagram of the internal circuitry on the stand–alone pressure
sensor chip.
VS
3
SCALE 1:1
THIN FILM
TEMPERATURE
COMPENSATION
AND
CALIBRATION
CIRCUITRY
SENSING
ELEMENT
2
4
MPXM2010GS/GST1
CASE 1320A
Vout+
PIN NUMBER
Vout–
1
Gnd
3
VS
2
+Vout
4
–Vout
1
GND
Figure 1. Temperature Compensated Pressure Sensor Schematic
VOLTAGE OUTPUT versus APPLIED DIFFERENTIAL PRESSURE
The differential voltage output of the sensor is directly proportional to the differential
pressure applied.
The output voltage of the differential or gauge sensor increases with increasing
pressure applied to the pressure side (P1) relative to the vacuum side (P2). Similarly,
output voltage increases as increasing vacuum is applied to the vacuum side (P2)
relative to the pressure side (P1).
Preferred devices are Motorola recommended choices for future use and best overall value.
REV 1
3–158
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPXM2010 SERIES
MAXIMUM RATINGS(NOTE)
Rating
Maximum Pressure (P1 > P2)
Storage Temperature
Operating Temperature
Symbol
Value
Unit
Pmax
75
kPa
Tstg
– 40 to +125
°C
TA
– 40 to +125
°C
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 10 Vdc, TA = 25°C unless otherwise noted, P1 > P2)
Characteristic
Symbol
Min
Typ
Max
Unit
Pressure Range(1)
POP
0
—
10
kPa
Supply Voltage(2)
VS
—
10
16
Vdc
Supply Current
Io
—
6.0
—
mAdc
VFSS
24
25
26
mV
Voff
–1.0
—
1.0
mV
Sensitivity
∆V/∆P
—
2.5
—
mV/kPa
Linearity(5)
—
–1.0
—
1.0
%VFSS
Pressure Hysteresis(5) (0 to 10 kPa)
—
—
± 0.1
—
%VFSS
Full Scale Span(3)
Freescale Semiconductor, Inc...
Offset(4)
Temperature Hysteresis(5) (– 40°C to +125°C)
Temperature Effect on Full Scale Span(5)
Temperature Effect on Offset(5)
Input Impedance
—
—
± 0.5
—
%VFSS
TCVFSS
–1.0
—
1.0
%VFSS
TCVoff
–1.0
—
1.0
mV
Zin
1000
—
2550
Ω
Zout
1400
—
3000
Ω
Response Time(6) (10% to 90%)
tR
—
1.0
—
ms
Warm–Up
—
—
20
—
ms
Offset Stability(7)
—
—
± 0.5
—
%VFSS
Output Impedance
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range. Operating the device above the specified excitation range may induce additional
error due to device self–heating.
3. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
4. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
5. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure, using end point method, over the specified
pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation at full rated pressure over the temperature range of 0 to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative
to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Offset stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–159
Freescale Semiconductor, Inc.
LINEARITY
Linearity refers to how well a transducer’s output follows
the equation: Vout = Voff + sensitivity x P over the operating
pressure range. There are two basic methods for calculating
nonlinearity: (1) end point straight line fit (see Figure 2) or (2)
a least squares best line fit. While a least squares fit gives
the “best case” linearity error (lower numerical value), the
calculations required are burdensome.
Conversely, an end point fit will give the “worst case” error
(often more desirable in error budget calculations) and the calculations are more straightforward for the user. Motorola’s
specified pressure sensor linearities are based on the end
point straight line method measured at the midrange pressure.
LEAST
SQUARE
DEVIATION
LEAST SQUARES FIT
EXAGGERATED
PERFORMANCE
CURVE
RELATIVE VOLTAGE OUTPUT
MPXM2010 SERIES
STRAIGHT LINE
DEVIATION
END POINT
STRAIGHT LINE FIT
OFFSET
50
PRESSURE (% FULLSCALE)
100
Figure 2. Linearity Specification Comparison
ON–CHIP TEMPERATURE COMPENSATION and CALIBRATION
Figure 3 shows the minimum, maximum and typical output
characteristics of the MPXM2010 series at 25°C. The output
is directly proportional to the differential pressure and is essentially a straight line.
A silicone gel isolates the die surface and wire bonds from
the environment, while allowing the pressure signal to be
transmitted to the silicon diaphragm.
VS = 10 Vdc
TA = 25°C
P1 > P2
30
OUTPUT (mVdc)
Freescale Semiconductor, Inc...
0
25
20
aMAX
15
TYP
SPAN
RANGE
(TYP)
10
MIN
5
0
–5
kPa
PSI
2.5
0.362
5
0.725
7.5
1.09
10
1.45
OFFSET
(TYP)
Figure 3. Output versus Pressure Differential
ORDERING INFORMATION
Device Type
3–160
Options
Case No
No.
MPXM2010D
Non–ported
1320
MPXM2010DT1
Non–ported, Tape and Reel
1320
MPXM2010GS
Ported
1320A
MPXM2010GST1
Ported, Tape and Reel
1320A
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
50 kPa
On-Chip Temperature
Compensated & Calibrated
Silicon Pressure Sensors
MPXM2053
SERIES
The MPXM2053 device is a silicon piezoresistive pressure sensor providing a highly
accurate and linear voltage output — directly proportional to the applied pressure. The
sensor is a single, monolithic silicon diaphragm with the strain gauge and a thin–film
resistor network integrated on–chip. The chip is laser trimmed for precise span and offset
calibration and temperature compensation.
Motorola Preferred Device
0 to 50 kPa (0 to 7.25 psi)
40 mV FULL SCALE SPAN
(TYPICAL)
Freescale Semiconductor, Inc...
Features
• Temperature Compensated Over 0°C to + 85°C
• Available in Easy–to–Use Tape & Reel
MPAK PACKAGE
• Ratiometric to Supply Voltage
• Gauge Ported & Non Ported Options
Application Examples
• Pump/Motor Controllers
• Robotics
SCALE 1:1
• Level Indicators
MPXM2053D/DT1
CASE 1320
• Medical Diagnostics
• Pressure Switching
• Non–Invasive Blood Pressure Measurement
Figure 1 shows a block diagram of the internal circuitry on the stand–alone pressure
sensor chip.
VS
SCALE 1:1
3
THIN FILM
TEMPERATURE
COMPENSATION
AND
CALIBRATION
CIRCUITRY
X–ducer
SENSING
ELEMENT
2
4
MPXM2053GS/GST1
CASE 1320A
Vout+
Vout–
1
PIN NUMBER
1
Gnd
3
VS
2
+Vout
4
–Vout
GND
Figure 1. Temperature Compensated Pressure Sensor Schematic
VOLTAGE OUTPUT versus APPLIED DIFFERENTIAL PRESSURE
The differential voltage output of the sensor is directly proportional to the differential
pressure applied.
The output voltage of the differential or gauge sensor increases with increasing
pressure applied to the pressure side (P1) relative to the vacuum side (P2). Similarly,
output voltage increases as increasing vacuum is applied to the vacuum side (P2)
relative to the pressure side (P1).
Preferred devices are Motorola recommended choices for future use and best overall value.
REV 1
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–161
Freescale Semiconductor, Inc.
MPXM2053 SERIES
MAXIMUM RATINGS(NOTE)
Rating
Maximum Pressure (P1 > P2)
Storage Temperature
Operating Temperature
Symbol
Value
Unit
Pmax
200
kPa
Tstg
– 40 to +125
°C
TA
– 40 to +125
°C
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 10 Vdc, TA = 25°C unless otherwise noted, P1 > P2)
Characteristic
Symbol
Typ
Max
Unit
0
—
50
kPa
—
10
16
Vdc
—
6.0
—
mAdc
VFSS
38.5
40
41.5
mV
Voff
–1.0
—
1.0
mV
Sensitivity
∆V/∆P
—
0.8
—
mV/kPa
Linearity(5)
—
– 0.6
—
0.4
%VFSS
Pressure Hysteresis(5) (0 to 50 kPa)
—
—
± 0.1
—
%VFSS
Temperature Hysteresis(5) (– 40°C to +125°C)
—
—
± 0.5
—
%VFSS
TCVFSS
–2.0
—
2.0
%VFSS
TCVoff
–1.0
—
1.0
mV
Zin
1000
—
2500
Ω
Pressure Range(1)
POP
Supply Voltage(2)
VS
Supply Current
Io
Full Scale Span(3)
Freescale Semiconductor, Inc...
Offset(4)
Temperature Effect on Full Scale Span(5)
Temperature Effect on Offset(5)
Input Impedance
Min
Zout
1400
—
3000
Ω
Response Time(6) (10% to 90%)
tR
—
1.0
—
ms
Warm–Up
—
—
20
—
ms
Offset Stability(7)
—
—
± 0.5
—
%VFSS
Output Impedance
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range. Operating the device above the specified excitation range may induce additional
error due to device self–heating.
3. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
4. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
5. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure, using end point method, over the specified
pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation at full rated pressure over the temperature range of 0 to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative
to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Offset stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
3–162
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
LINEARITY
Linearity refers to how well a transducer’s output follows
the equation: Vout = Voff + sensitivity x P over the operating
pressure range. There are two basic methods for calculating
nonlinearity: (1) end point straight line fit (see Figure 2) or (2)
a least squares best line fit. While a least squares fit gives
the “best case” linearity error (lower numerical value), the
calculations required are burdensome.
Conversely, an end point fit will give the “worst case” error
(often more desirable in error budget calculations) and the calculations are more straightforward for the user. Motorola’s
specified pressure sensor linearities are based on the end
point straight line method measured at the midrange pressure.
MPXM2053 SERIES
LEAST SQUARES FIT
RELATIVE VOLTAGE OUTPUT
EXAGGERATED
PERFORMANCE
CURVE
LEAST
SQUARE
DEVIATION
STRAIGHT LINE
DEVIATION
END POINT
STRAIGHT LINE FIT
OFFSET
50
PRESSURE (% FULLSCALE)
100
Figure 2. Linearity Specification Comparison
ON–CHIP TEMPERATURE COMPENSATION and CALIBRATION
A silicone gel isolates the die surface and wire bonds from
the environment, while allowing the pressure signal to be
transmitted to the silicon diaphragm.
Figure 3 shows the minimum, maximum and typical output
characteristics of the MPXM2053 series at 25°C. The output
is directly proportional to the differential pressure and is essentially a straight line.
VS = 10 Vdc
TA = 25°C
P1 > P2
40
35
OUTPUT (mVdc)
Freescale Semiconductor, Inc...
0
30
25
20
TYP
SPAN
RANGE
(TYP)
MAX
15
10
MIN
5
kPa
PSI
0
–5
0
12.5
1.8
25
3.6
37.5
5.4
50
7.25
OFFSET
(TYP)
Figure 3. Output versus Pressure Differential
ORDERING INFORMATION
Device Type
Options
Case No
No.
MPXM2053D
Non–ported
1320
MPXM2053DT1
Non–ported, Tape and Reel
1320
MPXM2053GS
Ported
1320A
MPXM2053GST1
Ported, Tape and Reel
1320A
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–163
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
100 kPa
On-Chip Temperature
Compensated & Calibrated
Silicon Pressure Sensors
MPXM2102
SERIES
The MPXM2102 device is a silicon piezoresistive pressure sensors providing a highly
accurate and linear voltage output — directly proportional to the applied pressure. The
sensor is a single, monolithic silicon diaphragm with the strain gauge and a thin–film
resistor network integrated on–chip. The chip is laser trimmed for precise span and offset
calibration and temperature compensation.
Motorola Preferred Device
0 to 100 kPa (0 to 14.5 psi)
40 mV FULL SCALE SPAN
(TYPICAL)
Freescale Semiconductor, Inc...
Features
• Temperature Compensated Over 0°C to + 85°C
MPAK PACKAGE
• Available in Easy-to-Use Tape & Reel
• Ratiometric to Supply Voltage
• Gauge Ported & Non Ported Options
Application Examples
• Pump/Motor Controllers
• Robotics
• Level Indicators
• Medical Diagnostics
• Pressure Switching
• Barometers
• Altimeters
SCALE 1:1
CASE 1320
Figure 1 shows a block diagram of the internal circuitry on the stand–alone pressure
sensor chip.
SCALE 1:1
VS
CASE 1320A
3
THIN FILM
TEMPERATURE
COMPENSATION
AND
CALIBRATION
CIRCUITRY
X–ducer
SENSING
ELEMENT
2
4
PIN NUMBER
Vout+
Vout–
1
Gnd
3
VS
2
+Vout
4
–Vout
1
GND
Figure 1. Temperature Compensated Pressure Sensor Schematic
VOLTAGE OUTPUT versus APPLIED DIFFERENTIAL PRESSURE
The differential voltage output of the sensor is directly proportional to the differential
pressure applied.
The output voltage of the differential or gauge sensor increases with increasing
pressure applied to the pressure side (P1) relative to the vacuum side (P2). Similarly,
output voltage increases as increasing vacuum is applied to the vacuum side (P2)
relative to the pressure side (P1).
Preferred devices are Motorola recommended choices for future use and best overall value.
REV 1
3–164
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPXM2102 SERIES
MAXIMUM RATINGS(NOTE)
Rating
Symbol
Value
Unit
Pmax
200
kPa
Tstg
– 40 to +125
°C
Operating Temperature
TA
– 40 to +125
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
°C
Maximum Pressure (P1 > P2)
Storage Temperature
OPERATING CHARACTERISTICS (VS = 10 Vdc, TA = 25°C unless otherwise noted, P1 > P2)
Characteristic
POP
Supply Voltage(2)
VS
Supply Current
Full Scale Span(3)
Offset(4)
Freescale Semiconductor, Inc...
Symbol
Pressure Range(1)
MPXM2102D/G Series
MPXM2102A Series
Sensitivity
Linearity(5)
MPXM2102D/G Series
MPXM2102A Series
Pressure Hysteresis(5) (0 to 100 kPa)
Temperature Hysteresis(5) (– 40°C to +125°C)
Temperature Effect on Full Scale Span(5)
Temperature Effect on Offset(5)
Input Impedance
Min
Typ
Max
Unit
0
—
100
kPa
—
10
16
Vdc
Io
—
6.0
—
mAdc
VFSS
38.5
40
41.5
mV
Voff
–1.0
– 2.0
—
—
1.0
2.0
mV
∆V/∆P
—
0.4
—
mV/kPa
—
—
– 0.6
– 1.0
—
—
0.4
1.0
%VFSS
—
—
± 0.1
—
%VFSS
—
—
± 0.5
—
%VFSS
TCVFSS
–2.0
—
2.0
%VFSS
TCVoff
–1.0
—
1.0
mV
Zin
1000
—
2500
Ω
Zout
1400
—
3000
Ω
Response Time(6) (10% to 90%)
tR
—
1.0
—
ms
Warm–Up
—
—
20
—
ms
Offset Stability(7)
—
—
± 0.5
—
%VFSS
Output Impedance
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range. Operating the device above the specified excitation range may induce additional
error due to device self–heating.
3. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
4. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
5. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure, using end point method, over the specified
pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation at full rated pressure over the temperature range of 0 to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative
to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Offset stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–165
Freescale Semiconductor, Inc.
MPXM2102 SERIES
LINEARITY
Linearity refers to how well a transducer’s output follows
the equation: Vout = Voff + sensitivity x P over the operating
pressure range. There are two basic methods for calculating
nonlinearity: (1) end point straight line fit (see Figure 2) or (2)
a least squares best line fit. While a least squares fit gives
the “best case” linearity error (lower numerical value), the
calculations required are burdensome.
Conversely, an end point fit will give the “worst case” error
(often more desirable in error budget calculations) and the calculations are more straightforward for the user. Motorola’s
specified pressure sensor linearities are based on the end
point straight line method measured at the midrange pressure.
LEAST
SQUARE
DEVIATION
LEAST SQUARES FIT
RELATIVE VOLTAGE OUTPUT
EXAGGERATED
PERFORMANCE
CURVE
STRAIGHT LINE
DEVIATION
END POINT
STRAIGHT LINE FIT
OFFSET
50
PRESSURE (% FULLSCALE)
100
Figure 2. Linearity Specification Comparison
ON–CHIP TEMPERATURE COMPENSATION and CALIBRATION
A silicone gel isolates the die surface and wire bonds from
the environment, while allowing the pressure signal to be
transmitted to the silicon diaphragm.
Figure 3 shows the minimum, maximum and typical output
characteristics of the MPXM2102 series at 25°C. The output
is directly proportional to the differential pressure and is essentially a straight line.
40
VS = 10 Vdc
TA = 25°C
P1 > P2
35
OUTPUT (mVdc)
Freescale Semiconductor, Inc...
0
30
25
20
TYP
SPAN
RANGE
(TYP)
MAX
15
10
MIN
5
kPa
PSI
0
–5
0
25
3.62
50
7.25
75
10.87
100
14.5
OFFSET
(TYP)
Figure 3. Output versus Pressure Differential
ORDERING INFORMATION
Device Type
3–166
Options
Case Type
MPXM2102D
Non–ported
1320
MPXM2102DT1
Non–ported, Tape and Reel
1320
MPXM2102GS
Ported
1320A
MPXM2102GST1
Ported, Tape and Reel
1320A
MPXM2102A
Non–ported
1320
MPXM2102AT1
Non–ported, Tape and Reel
1320
MPXM2102AS
Ported
1320A
MPXM2102AST1
Ported, Tape and Reel
1320A
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
200 kPa
On-Chip Temperature
Compensated & Calibrated
Silicon Pressure Sensors
MPXM2202
SERIES
The MPXM2202 device is a silicon piezoresistive pressure sensors providing a highly
accurate and linear voltage output — directly proportional to the applied pressure. The
sensor is a single, monolithic silicon diaphragm with the strain gauge and a thin–film
resistor network integrated on–chip. The chip is laser trimmed for precise span and offset
calibration and temperature compensation.
Motorola Preferred Device
0 to 200 kPa (0 to 29 psi)
40 mV FULL SCALE SPAN
(TYPICAL)
Freescale Semiconductor, Inc...
Features
• Temperature Compensated Over 0°C to + 85°C
MPAK PACKAGE
• Available in Easy-to-Use Tape & Reel
• Ratiometric to Supply Voltage
• Gauge Ported & Non Ported Options
Application Examples
• Pump/Motor Controllers
• Robotics
• Level Indicators
• Medical Diagnostics
• Pressure Switching
• Barometers
• Altimeters
SCALE 1:1
CASE 1320
Figure 1 shows a block diagram of the internal circuitry on the stand–alone pressure
sensor chip.
SCALE 1:1
VS
CASE 1320A
3
THIN FILM
TEMPERATURE
COMPENSATION
AND
CALIBRATION
CIRCUITRY
X–ducer
SENSING
ELEMENT
2
4
PIN NUMBER
Vout+
Vout–
1
Gnd
3
VS
2
+Vout
4
–Vout
1
GND
Figure 1. Temperature Compensated Pressure Sensor Schematic
VOLTAGE OUTPUT versus APPLIED DIFFERENTIAL PRESSURE
The differential voltage output of the sensor is directly proportional to the differential
pressure applied.
The output voltage of the differential or gauge sensor increases with increasing
pressure applied to the pressure side (P1) relative to the vacuum side (P2). Similarly,
output voltage increases as increasing vacuum is applied to the vacuum side (P2)
relative to the pressure side (P1).
Preferred devices are Motorola recommended choices for future use and best overall value.
REV 0
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
Go to: www.freescale.com
3–167
Freescale Semiconductor, Inc.
MPXM2202 SERIES
MAXIMUM RATINGS(NOTE)
Rating
Symbol
Value
Unit
Pmax
400
kPa
Tstg
– 40 to +125
°C
Operating Temperature
TA
– 40 to +125
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
°C
Maximum Pressure (P1 > P2)
Storage Temperature
OPERATING CHARACTERISTICS (VS = 10 Vdc, TA = 25°C unless otherwise noted, P1 > P2)
Characteristic
Symbol
Pressure Range(1)
POP
Supply Voltage(2)
VS
Supply Current
Full Scale Span(3)
Freescale Semiconductor, Inc...
Offset(4)
MPXM2202D/G Series
MPXM2202A Series
Sensitivity
Linearity(5)
MPXM2202D/G Series
MPXM2202A Series
Pressure Hysteresis(5) (0 to 100 kPa)
Temperature Hysteresis(5) (– 40°C to +125°C)
Temperature Effect on Full Scale Span(5)
Temperature Effect on Offset(5)
Input Impedance
Min
Typ
Max
Unit
0
—
200
kPa
—
10
16
Vdc
Io
—
6.0
—
mAdc
VFSS
38.5
40
41.5
mV
Voff
–1.0
– 2.0
—
—
1.0
2.0
mV
∆V/∆P
—
0.2
—
mV/kPa
—
—
– 0.6
– 1.0
—
—
0.4
1.0
%VFSS
—
—
± 0.1
—
%VFSS
—
—
± 0.5
—
%VFSS
TCVFSS
–2.0
—
2.0
%VFSS
TCVoff
–1.0
—
1.0
mV
Zin
1000
—
2500
Ω
Zout
1400
—
3000
Ω
Response Time(6) (10% to 90%)
tR
—
1.0
—
ms
Warm–Up
—
—
20
—
ms
Offset Stability(7)
—
—
± 0.5
—
%VFSS
Output Impedance
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range. Operating the device above the specified excitation range may induce additional
error due to device self–heating.
3. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
4. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
5. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure, using end point method, over the specified
pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• TcSpan:
Output deviation at full rated pressure over the temperature range of 0 to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85°C, relative
to 25°C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Offset stability is the product’s output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
3–168
For www.motorola.com/semiconductors
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
LINEARITY
Linearity refers to how well a transducer’s output follows
the equation: Vout = Voff + sensitivity x P over the operating
pressure range. There are two basic methods for calculating
nonlinearity: (1) end point straight line fit (see Figure 2) or (2)
a least squares best line fit. While a least squares fit gives
the “best case” linearity error (lower numerical value), the
calculations required are burdensome.
Conversely, an end point fit will give the “worst case” error
(often more desirable in error budget calculations) and the calculations are more straightforward for the user. Motorola’s
specified pressure sensor linearities are based on the end
point straight line method measured at the midrange pressure.
MPXM2202 SERIES
LEAST SQUARES FIT
RELATIVE VOLTAGE OUTPUT
EXAGGERATED
PERFORMANCE
CURVE
LEAST
SQUARE
DEVIATION
STRAIGHT LINE
DEVIATION
END POINT
STRAIGHT LINE FIT
OFFSET
50
PRESSURE (% FULLSCALE)
100
Figure 2. Linearity Specification Comparison
ON–CHIP TEMPERATURE COMPENSATION and CALIBRATION
A silicone gel isolates the die surface and wire bonds from
the environment, while allowing the pressure signal to be
transmitted to the silicon diaphragm.
Figure 3 shows the minimum, maximum and typical output
characteristics of the MPXM2202 series at 25°C. The output
is directly proportional to the differential pressure and is essentially a straight line.
40
35
OUTPUT (mVdc)
Freescale Semiconductor, Inc...
0
VS = 10 Vdc
TA = 25°C
P1 > P2
TYP
30
25
SPAN
RANGE
(TYP)
MAX
20
15
10
MIN
5
0
–5
kPa 0
PSI
50
7.25
25
100
14.5
75
125
150
21.75
175
OFFSET
200
29
PRESSURE
Figure 3. Output versus Pressure Differential
ORDERING INFORMATION
No
Device Type/Order No.
Options
Case Type
MPXM2202D
Non–ported
1320
MPXM2202DT1
Non–ported, Tape and Reel
1320
MPXM2202GS
Ported
1320A
MPXM2202GST1
Ported, Tape and Reel
1320A
MPXM2202A
Non–ported
1320
MPXM2202AT1
Non–ported, Tape and Reel
1320
MPXM2202AS
Ported
1320A
MPXM2202AST1
Ported, Tape and Reel
1320A
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
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3–169
Freescale Semiconductor, Inc.
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Integrated Silicon Pressure Sensor
MPXV4006G
On-Chip Signal Conditioned,
SERIES
Temperature Compensated
and Calibrated
The MPXV4006G series piezoresistive transducer is a state–of–the–art monolithic
silicon pressure sensor designed for a wide range of applications, but particularly those
employing a microcontroller or microprocessor with A/D inputs. This sensor combines a
highly sensitive implanted strain gauge with advanced micromachining techniques,
thin–film metallization, and bipolar processing to provide an accurate, high level analog
output signal that is proportional to the applied pressure.
INTEGRATED
PRESSURE SENSOR
0 to 6 kPa (0 to 0.87 psi)
0.2 to 4.7 V OUTPUT
Freescale Semiconductor, Inc...
Features
• Temperature Compensated over 10° to 60°C
• Ideally Suited for Microprocessor or Microcontroller–
Based Systems
SMALL OUTLINE PACKAGE
THROUGH–HOLE
SMALL OUTLINE PACKAGE
SURFACE MOUNT
J
• Available in Gauge Surface Mount (SMT) or Through–
hole (DIP) Configurations
• Durable Thermoplastic (PPS) Package
MPXV4006G6U
CASE 482
VS
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
MPXV4006G7U
CASE 482B
Vout
MPXV4006GC6U
CASE 482A
MPXV4006GC7U
CASE 482C
PINS 1, 5, 6, 7, AND 8 ARE NO CONNECTS
FOR SMALL OUTLINE PACKAGE DEVICE
GND
Figure 1. Fully Integrated Pressure Sensor
Schematic
PIN NUMBER
MPXV4006GP
CASE 1369
1
N/C
5
N/C
2
6
N/C
3
VS
Gnd
7
N/C
4
Vout
8
N/C
NOTE: Pins 1, 5, 6, 7, and 8 are
internal device connections. Do not
connect to external circuitry or
ground. Pin 1 is noted by the notch
in the lead.
MPXV4006DP
CASE 1351
Replaces MPXT4006D/D
REV 4
3–170
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More Information On This Product,
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPXV4006G SERIES
MAXIMUM RATINGS(NOTE)
Parametrics
Maximum Pressure (P1 > P2)
Storage Temperature
Operating Temperature
Symbol
Value
Unit
Pmax
24
kPa
Tstg
– 30 to +100
°C
TA
+10 to +60
°C
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 5.0 Vdc, TA = 25°C unless otherwise noted, P1 > P2. Decoupling circuit shown in Figure 3
required to meet electrical specifications.)
Characteristic
Pressure Range
Supply Voltage(1)
Freescale Semiconductor, Inc...
Supply Current
Symbol
Min
Typ
Max
Unit
POP
0
—
6.0
kPa
VS
4.75
5.0
5.25
Vdc
IS
—
—
10
mAdc
Full Scale Span(2)
(RL = 51kΩ)
VFSS
—
4.6
—
V
Offset(3)(5)
(RL = 51kΩ)
Voff
0.100
0.225
0.430
V
V/P
—
766
—
mV/kPa
—
—
—
± 5.0
%VFSS
Sensitivity
Accuracy(4)(5)
(10 to 60°C)
NOTES:
1. Device is ratiometric within this specified excitation range.
2. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
3. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
4. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• Offset Stability:
Output deviation, after 1000 temperature cycles, 30 to 100°C, and 1.5 million pressure cycles, with
minimum rated pressure applied.
• TcSpan:
Output deviation over the temperature range of 10 to 60°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 10 to 60°C,
relative to 25°C.
• Variation from Nominal: The variation from nominal values, for Offset or Full Scale Span, as a percent of VFSS, at 25°C.
5. Auto Zero at Factory Installation: Due to the sensitivity of the MPXV4006G, external mechanical stresses and mounting position can affect
the zero pressure output reading. To obtain the 5% FSS accuracy, the device output must be “autozeroed’’ after installation. Autozeroing
is defined as storing the zero pressure output reading and subtracting this from the device’s output during normal operations.
*
Motorola Sensor Device Data
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Information On This Product,
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3–171
Freescale Semiconductor, Inc.
MPXV4006G SERIES
ON–CHIP TEMPERATURE COMPENSATION, CALIBRATION AND SIGNAL CONDITIONING
test for dry air, and other media, are available from the factory.
Contact the factory for information regarding media tolerance
in your application.
Figure 3 shows the recommended decoupling circuit for interfacing the output of the integrated sensor to the A/D input
of a microprocessor or microcontroller. Proper decoupling of
the power supply is recommended.
Figure 4 shows the sensor output signal relative to pressure input. Typical, minimum and maximum output curves
are shown for operation over a temperature range of 10°C to
60°C using the decoupling circuit shown in Figure 3. The
output will saturate outside of the specified pressure range.
DIE
FLUOROSILICONE
GEL DIE COAT
+5 V
STAINLESS
STEEL CAP
P1
WIRE BOND
Vout
THERMOPLASTIC
CASE
OUTPUT
Vs
IPS
LEAD
FRAME
m
1.0 F
m
0.01 F
GND
470 pF
P2
DIE BOND
DIFFERENTIAL SENSING
ELEMENT
Figure 2. Cross–Sectional Diagram (Not to Scale)
Figure 3. Recommended power supply decoupling
and output filtering recommendations.
For additional output filtering, please refer to
Application Note AN1646.
5.0
OUTPUT (V)
Freescale Semiconductor, Inc...
The performance over temperature is achieved by integrating the shear–stress strain gauge, temperature compensation, calibration and signal conditioning circuitry onto a
single monolithic chip.
Figure 2 illustrates the gauge configuration in the basic chip
carrier (Case 482). A fluorosilicone gel isolates the die surface
and wire bonds from the environment, while allowing the pressure signal to be transmitted to the silicon diaphragm.
The MPXV4006G series sensor operating characteristics
are based on use of dry air as pressure media. Media, other
than dry air, may have adverse effects on sensor performance
and long–term reliability. Internal reliability and qualification
TRANSFER FUNCTION:
4.5 Vout = VS*[(0.1533*P) + 0.045] ± 5% VFSS
4.0 VS = 5.0 V ± 0.25 Vdc
TEMP = 10 to 60°C
3.5
3.0
TYPICAL
2.5
2.0
MAX
1.5
MIN
1.0
0.5
0
0
3
DIFFERENTIAL PRESSURE (kPa)
6
Figure 4. Output versus Pressure Differential
(See Note 5 in Operating Characteristics)
3–172
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPXV4006G SERIES
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing silicone gel which
isolates the die from the environment. The Motorola pres-
Freescale Semiconductor, Inc...
Part Number
sure sensor is designed to operate with positive differential
pressure applied, P1 > P2.
The Pressure (P1) side may be identified by using the table
below:
Case Type
Pressure (P1) Side Identifier
MPXV4006G6U/T1
482
Stainless Steel Cap
MPXV4006GC6U/T1
482A
Side with Port Attached
MPXV4006G7U
482B
Stainless Steel Cap
MPXV4006GC7U
482C
Side with Port Attached
MPXV4006GP
1369
Side with Port Attached
MPXV4006DP
1351
Side with Part Marking
ORDERING INFORMATION
MPXV4006G series pressure sensors are available in the basic element package or with pressure ports. Two packing options
are offered for the 482 and 482A case configurations.
Device Type
Basic Element
Ported Element
Options
Case No.
MPX Series Order No.
Packing Options
Marking
Element Only
482
MPXV4006G6U
Rails
MPXV4006G
Element Only
482
MPXV4006G6T1
Tape and Reel
MPXV4006G
Element Only
482
MPXV4006G7U
Rails
MPXV4006G
Axial Port
482A
MPXV4006GC6U
Rails
MPXV4006G
Axial Port
482A
MPXV4006GC6T1
Tape and Reel
MPXV4006G
Axial Port
482A
MPXV4006GC7U
Rails
MPXV4006G
Side Port
1369
MPXV4006GP
Trays
MPXV4006G
Dual Port
1351
MPXV4006DP
Trays
MPXV4006G
MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS
Surface mount board layout is a critical portion of the total
design. The footprint for the surface mount packages must
be the correct size to ensure proper solder connection interface between the board and the package. With the correct
footprint, the packages will self align when subjected to a solder reflow process. It is always recommended to design
boards with a solder mask layer to avoid bridging and shorting between solder pads.
0.100 TYP 8X
2.54
0.660
16.76
0.060 TYP 8X
1.52
0.300
7.62
0.100 TYP 8X
2.54
inch
mm
SCALE 2:1
Figure 5. SOP Footprint (Case 482)
Motorola Sensor Device Data
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Information On This Product,
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3–173
Freescale Semiconductor, Inc.
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Integrated Silicon Pressure Sensor
On-Chip Signal Conditioned,
MPXV4115V
SERIES
Temperature Compensated
Freescale Semiconductor, Inc...
and Calibrated
The MPXV4115V series piezoresistive transducer is a state–of–the–art monolithic
silicon pressure sensor designed for a wide range of applications, particularly those
employing a microcontroller with A/D inputs. This transducer combines advanced
micromachining techniques, thin–film metallization and bipolar processing to provide an
accurate, high–level analog output signal that is proportional to the applied pressure/vacuum. The small form factor and high reliability of on–chip integration make the Motorola
sensor a logical and economical choice for the automotive system designer. Figure 1
shows a block diagram of the internal circuitry integrated on a pressure sensor chip.
INTEGRATED
PRESSURE SENSOR
–115 to 0 kPa (–16.7 to 2.2 psi)
0.2 to 4.6 V OUTPUT
SMALL OUTLINE PACKAGE
Features
• 1.5 % Maximum error over 0° to 85°C
• Temperature Compensated from –40° + 125°C
• Ideally Suited for Microprocessor or Microcontroller–Based Systems
• Durable Thermoplastic (PPS) Surface Mount Package
MPXV4115VC6U
CASE 482A
Application Examples
• Vacuum Pump Monitoring
• Brake Booster Monitoring
VS
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
MPXV4115V6U
CASE 482
Vout
PINS 1, 5, 6, 7 AND 8 ARE NO CONNECTS
FOR SMALL OUTLINE PACKAGE DEVICE
GND
PIN NUMBER
1
N/C
5
N/C
2
VS
Gnd
6
N/C
3
7
N/C
4
Vout
8
N/C
Figure 1. Fully Integrated Pressure Sensor Schematic
NOTE: Pins 1, 5, 6, 7, and 8 are
internal device connections. Do not
connect to external circuitry or ground.
Pin 1 is noted by the notch in the lead.
REV 1
3–174
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPXV4115V SERIES
MAXIMUM RATINGS(NOTE)
Parametrics
Maximum Pressure
Storage Temperature
Operating Temperature
Symbol
Value
Unit
Pmax
400
kPa
Tstg
– 40 to + 125
°C
TA
–40 to + 125
°C
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 5 Vdc, TA = 25° C unless otherwise noted. Decoupling circuit shown in Figure 3 required to
meet electrical specifications.)
Characteristic
Symbol
Min
Typ
Max
Unit
Pressure Range (Differential mode, Vacuum on metal cap side, Atmospheric pressure on back side)
POP
–115
—
0
kPa
VS
4.75
5
5.25
Vdc
Supply Voltage(1)
Freescale Semiconductor, Inc...
Supply Current
Io
—
6.0
10
mAdc
Full Scale Output (2) (0 to 85° C)
(Pdiff = 0 kPa) 2
VFSO
4.535
4.6
4.665
Vdc
Full Scale Span (3) (0 to 85° C)
@Vs = 5.0 V
VFSS
Accuracy (4) (0 to 85° C)
4.4
Vdc
—
—
1.5%
%VFSS
V/P
—
38.26
—
mV/kPa
Response Time (5)
tR
—
1.0
—
ms
Output Source Current at Full Scale Output
Io
—
0.1
—
mAdc
Warm–Up Time (6)
—
—
20
—
ms
—
± 0.5
—
%VFSS
Sensitivity
Offset Stability (7)
NOTES:
1. Device is ratiometric within the specified excitation voltage range.
2. Full–scale output is defined as the output voltage at the maximum or full–rated pressure.
3. Full–scale span is defined as the algebraic difference between the output voltage at full–rated pressure and the output voltage at the minimum–rated pressure.
4. Accuracy is the deviation in actual output from nominal output over the entire pressure range and temperature range as a percent of span
at 25° C due to all sources of errors, including the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential
pressure applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from
minimum or maximum rated pressure at 25°C.
• TcSpan:
Output deviation over the temperature range of 0° to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum pressure applied, over the temperature range of 0° to 85°C, relative
to 25°C.
5. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
6. Warm–up Time is defined as the time required for the product to meet the specified output voltage after the pressure has been stabilized.
7. Offset Stability is the product’s output deviation when subjected to 1000 cycles of Pulsed Pressure, Temperature Cycling with Bias Test.
Motorola Sensor Device Data
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Information On This Product,
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3–175
Freescale Semiconductor, Inc.
MPXV4115V SERIES
ON–CHIP TEMPERATURE COMPENSATION, CALIBRATION AND SIGNAL CONDITIONING
Figure 3 shows the recommended decoupling circuit for
interfacing the output of the integrated sensor to the A/D input of a microprocessor or microcontroller. Proper decoupling of the power supply is recommended.
Figure 4 shows the sensor output signal relative to differential pressure input. Typical, minimum and maximum output curves are shown for operation over a temperature range
of 0°C to 85°C using the decoupling circuit shown in Figure 3.
The output will saturate outside of the specified pressure
range.
DIE
FLUOROSILICONE
GEL DIE COAT
+5 V
STAINLESS
STEEL CAP
P1
WIRE BOND
Vout
THERMOPLASTIC
CASE
OUTPUT
Vs
IPS
LEAD
FRAME
m
1.0 F
m
0.01 F
GND
470 pF
P2
DIE BOND
DIFFERENTIAL SENSING
ELEMENT
Figure 2. Cross–Sectional Diagram (Not to Scale)
Figure 3. Recommended power supply decoupling
and output filtering.
For additional output filtering, please refer to
Application Note AN1646.
TRANSFER FUNCTION MPXV4115V
5
OUTPUT (VOLTS)
Freescale Semiconductor, Inc...
The performance over temperature is achieved by integrating the shear–stress strain gauge, temperature compensation, calibration and signal conditioning circuitry onto a
single monolithic chip.
Figure 2 illustrates the gauge configuration in the basic chip
carrier (Case 482). A fluorosilicone gel isolates the die surface
and wire bonds from the environment, while allowing the pressure signal to be transmitted to the silicon diaphragm.
The MPXV4115V series sensor operating characteristics
are based on use of dry air as pressure media. Media, other
than dry air, may have adverse effects on sensor performance
and long–term reliability. Internal reliability and qualification
test for dry air, and other media, are available from the factory.
Contact the factory for information regarding media tolerance
in your application.
TRANSFER FUNCTION:
4.5 V = V *[(0.007652*P) + 0.92] ± (Pressure error
out S
4 *Temp Factor*0.007652*VS)
VS = 5.0 V ± 0.25 Vdc
3.5
TEMP = 0–85° C
3
2.5
2
1.5
MAX
MIN
1
0.5
0
–115
–95
–75
–55
Vout vs. VACUUM
–35
–15
Figure 4. Applied Vacuum in kPa (below
atmospheric pressure)
3–176
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPXV4115V SERIES
ORDERING INFORMATION
The MPXV4115V series pressure sensors are available in the basic element package or with a pressure port. Two packing
options are also offered.
Device Type
Case No
No.
MPXV4115V6U
Packing Options
Device Marking
482
Rails
MPXV4115V
MPXV4115V6T1
482
Tape and Reel
MPXV4115V
MPXV4115VC6U
482A
Rails
MPXV4115V
MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS
Freescale Semiconductor, Inc...
Surface mount board layout is a critical portion of the total
design. The footprint for the surface mount packages must
be the correct size to ensure proper solder connection interface between the board and the package. With the correct
fottprint, the packages will self align when subjected to a
solder reflow process. It is always recommended to design
boards with a solder mask layer to avoid bridging and shorting between solder pads.
0.100 TYP 8X
2.54
0.660
16.76
0.060 TYP 8X
1.52
0.300
7.62
0.100 TYP 8X
2.54
inch
mm
SCALE 2:1
Figure 5. SOP Footprint (Case 482)
Motorola Sensor Device Data
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3–177
Freescale Semiconductor, Inc.
MPXV4115V SERIES
Transfer Function
)
Nominal Transfer Value: Vout = VS (P x 0.007652 )
0.92)
+/– (Pressure Error x Temp. Factor x 0.007652 x VS)
VS = 5 V ± 0.25 Vdc
Temperature Error Band
MPXV4115V Series
4.0
3.0
Temperature
Error
Factor
2.0
Temp
Multiplier
– 40
0 to 85
+125
3
1
3
0.0
–40
–20
0
20
40
60
80
100
120
140
Temperature in C°
NOTE: The Temperature Multiplier is a linear response from 0° to –40°C and from 85° to 125°C.
Pressure Error Band
1.950
1.725
Pressure Error (kPa)
Freescale Semiconductor, Inc...
1.0
1.500
0
–115 –100
–85
–60
–45
–30
–15
Pressure in kPa
(below atmospheric)
0
–1.500
– 1.725
– 1.950
Pressure
–115 to 0 kPa
3–178
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Error (Max)
"1.725 (kPa)
Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
Integrated Silicon Pressure Sensor
On-Chip Signal Conditioned,
MPXV5004G
SERIES
Temperature Compensated
and Calibrated
INTEGRATED
PRESSURE SENSOR
0 to 3.92 kPa
(0 to 400 mm H2O)
1.0 to 4.9 V OUTPUT
Freescale Semiconductor, Inc...
The MPXV5004G series piezoresistive transducer is a state–of–the–art monolithic
silicon pressure sensor designed for a wide range of applications, but particularly those
employing a microcontroller or microprocessor with A/D inputs. This sensor combines a
highly sensitive implanted strain gauge with advanced micromachining techniques,
thin–film metallization, and bipolar processing to provide an accurate, high level analog
output signal that is proportional to the applied pressure.
Features
SMALL OUTLINE PACKAGE
SURFACE MOUNT
• Temperature Compensated over 10° to 60°C
SMALL OUTLINE PACKAGE
THROUGH–HOLE
• Available in Gauge Surface Mount (SMT) or Through–
hole (DIP) Configurations
• Durable Thermoplastic (PPS) Package
Application Examples
• Washing Machine Water Level
• Ideally Suited for Microprocessor or Microcontroller–
Based Systems
MPXV5004G6U
CASE 482
MPXV5004GC7U
CASE 482C
VS
J
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
MPXV5004GC6U
CASE 482A
Vout
MPXV5004G7U
CASE 482B
PINS 1, 5, 6, 7, AND 8 ARE NO CONNECTS
FOR SMALL OUTLINE PACKAGE DEVICE
GND
Figure 1. Fully Integrated Pressure Sensor
Schematic
MPXV5004GP
CASE 1369
MPXV5004DP
CASE 1351
PIN NUMBER
1
N/C
5
N/C
2
VS
Gnd
6
N/C
3
7
N/C
4
Vout
8
N/C
NOTE: Pins 1, 5, 6, 7, and 8 are
internal device connections. Do not
connect to external circuitry or
ground. Pin 1 is noted by the notch in
the lead.
MPXV5004GVP
CASE 1368
REV 5
Motorola Sensor Device Data
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For More
Information On This Product,
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3–179
MPXV5004G SERIES
Freescale Semiconductor, Inc.
MAXIMUM RATINGS(NOTE)
Parametrics
Maximum Pressure (P1 > P2)
Storage Temperature
Operating Temperature
Symbol
Value
Unit
Pmax
16
kPa
Tstg
– 30 to +100
°C
TA
0 to +85
°C
NOTE: Exposure beyond the specified limits may cause permanent damage or degradation to the device.
OPERATING CHARACTERISTICS (VS = 5.0 Vdc, TA = 25°C unless otherwise noted, P1 > P2. Decoupling circuit shown in Figure 3
required to meet electrical specifications)
Symbol
Min
Typ
Max
Unit
POP
0
—
3.92
400
kPa
mm H2O
Supply Voltage(1)
VS
4.75
5.0
5.25
Vdc
Supply Current
IS
—
—
10
mAdc
Characteristic
Freescale Semiconductor, Inc...
Pressure Range
Span at 306 mm H2O (3 kPa)(2)
VFSS
—
3.0
—
V
Offset(3)(5)
Voff
0.75
1.00
1.25
V
Sensitivity
V/P
—
1.0
9.8
—
V/kPa
mV/mm H2O
—
—
—
± 1.5
± 2.5
%VFSS
%VFSS
Accuracy(4)(5)
0 to 100 mm H2O
100 to 400 mm H2O
(10 to 60°C)
(10 to 60°C)
NOTES:
1. Device is ratiometric within this specified excitation range.
2. Span is defined as the algebraic difference between the output voltage at specified pressure and the output voltage at the minimum rated
pressure.
3. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
4. Accuracy (error budget) consists of the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
minimum or maximum rated pressure, at 25°C.
• Offset Stability:
Output deviation, after 1000 temperature cycles, 30 to 100°C, and 1.5 million pressure cycles, with
minimum rated pressure applied.
• TcSpan:
Output deviation over the temperature range of 10 to 60°C, relative to 25°C.
• TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 10 to 60°C,
relative to 25°C.
• Variation from Nominal: The variation from nominal values, for Offset or Full Scale Span, as a percent of VFSS, at 25°C.
5. Auto Zero at Factory Installation: Due to the sensitivity of the MPXV5004G, external mechanical stresses and mounting position can affect
the zero pressure output reading. Autozeroing is defined as storing the zero pressure output reading and subtracting this from the device’s
output during normal operations. Reference AN1636 for specific information. The specified accuracy assumes a maximum temperature
change of ± 5° C between autozero and measurement.
*
3–180
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MPXV5004G SERIES
ON–CHIP TEMPERATURE COMPENSATION, CALIBRATION AND SIGNAL CONDITIONING
test for dry air, and other media, are available from the factory.
Contact the factory for information regarding media tolerance
in your application.
Figure 3 shows the recommended decoupling circuit for interfacing the output of the MPXV5004G to the A/D input of
the microprocessor or microcontroller. Proper decoupling of
the power supply is recommended.
Figure 4 shows the sensor output signal relative to pressure input. Typical, minimum and maximum output curves
are shown for operation over a temperature range of 10°C to
60°C using the decoupling circuit shown in Figure 3. The
output will saturate outside of the specified pressure range.
DIE
FLUOROSILICONE
GEL DIE COAT
STAINLESS
STEEL CAP
+5 V
P1
WIRE BOND
Vout
THERMOPLASTIC
CASE
OUTPUT
Vs
IPS
LEAD
FRAME
m
1.0 F
m
0.01 F
GND
470 pF
P2
DIE BOND
DIFFERENTIAL SENSING
ELEMENT
Figure 2. Cross–Sectional Diagram (Not to Scale)
Figure 3. Recommended power supply decoupling
and output filtering.
For additional output filtering, please refer to
Application Note AN1646.
5.0
TRANSFER FUNCTION:
Vout = VS*[(0.2*P) + 0.2] ± 1.5% VFSS
VS = 5.0 V ± 0.25 Vdc
4.0 TEMP = 10 to 60°C
OUTPUT (V)
Freescale Semiconductor, Inc...
The performance over temperature is achieved by integrating the shear–stress strain gauge, temperature compensation, calibration and signal conditioning circuitry onto a
single monolithic chip.
Figure 2 illustrates the gauge configuration in the basic chip
carrier (Case 482). A fluorosilicone gel isolates the die surface
and wire bonds from the environment, while allowing the pressure signal to be transmitted to the silicon diaphragm.
The MPXV5004G series sensor operating characteristics
are based on use of dry air as pressure media. Media, other
than dry air, may have adverse effects on sensor performance
and long–term reliability. Internal reliability and qualification
TYPICAL
3.0
MAX
MIN
2.0
1.0
2 kPa
200 mm H2O
4 kPa
400 mm H2O
DIFFERENTIAL PRESSURE
Figure 4. Output versus Pressure Differential
(See Note 5 in Operating Characteristics)
Motorola Sensor Device Data
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MPXV5004G SERIES
Freescale Semiconductor, Inc.
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing silicone gel which
isolates the die from the environment. The Motorola pressure
Part Number
Case Type
MPXV5004GC6U/T1
Pressure (P1) Side Identifier
482A
MPXV5004G6U/T1
Freescale Semiconductor, Inc...
sensor is designed to operate with positive differential pressure applied, P1 > P2.
The Pressure (P1) side may be identified by using the table
below:
Side with Port Attached
482
Stainless Steel Cap
MPXV5004GC7U
482C
Side with Port Attached
MPXV5004G7U
482B
Stainless Steel Cap
MPXV5004GP
1369
Side with Port Attached
MPXV5004DP
1351
Side with Port Marking
MPXV5004GVP
1368
Stainless Steel Cap
ORDERING INFORMATION
MPXV5004G series pressure sensors are available in the basic element package or with a pressure port. Two packing
options are offered for the surface mount configuration.
No
Device Type / Order No.
Case No
No.
Packing Options
Device Marking
MPXV5004G6U
482
Rails
MPXV5004G
MPXV5004G6T1
482
Tape and Reel
MPXV5004G
MPXV5004GC6U
482A
Rails
MPXV5004G
MPXV5004GC6T1
482A
Tape and Reel
MPXV5004G
MPXV5004GC7U
482C
Rails
MPXV5004G
MPXV5004G7U
482B
Rails
MPXV5004G
MPXV5004GP
1369
Trays
MPXV5004G
MPXV5004DP
1351
Trays
MPXV5004G
MPXV5004GVP
1368
Trays
MPXV5004G
INFORMATION FOR USING THE SMALL OUTLINE PACKAGE (CASE 482)
MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS
Surface mount board layout is a critical portion of the total
design. The footprint for the surface mount packages must
be the correct size to ensure proper solder connection interface between the board and the package. With the correct
fottprint, the packages will self align when subjected to a
solder reflow process. It is always recommended to design
boards with a solder mask layer to avoid bridging and shorting between solder pads.
0.100 TYP 8X
2.54
0.660
16.76
0.060 TYP 8X
1.52
0.300
7.62
0.100 TYP 8X
2.54
inch
mm
SCALE 2:1
Figure 5. SOP Footprint (Case 482)
3–182
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MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
High Temperature Accuracy
Integrated Silicon Pressure Sensor
On-Chip Signal Conditioned,
MPXV6115VC6U
Temperature Compensated
Freescale Semiconductor, Inc...
and Calibrated
Motorola’s MPXV6115VC6U sensor integrates on–chip, bipolar op amp
circuitry and thin film resistor networks to provide a high output signal and
temperature compensation. The small form factor and high reliability of on–chip
integration make the Motorola pressure sensor a logical and economical choice
for the system designer.
The MPXV6115VC6U piezoresistive transducer is a state–of–the–art,
monolithic, signal conditioned, silicon pressure sensor. This sensor combines
advanced micromachining techniques, thin film metallization, and bipolar semiconductor processing to provide an accurate, high level analog output signal that is
proportional to applied pressure.
Figure 1 shows a block diagram of the internal circuitry integrated on a
pressure sensor chip.
INTEGRATED
PRESSURE SENSOR
–115 to 0 kPa (–16.7 to 2.2 psi)
0.2 to 4.6 Volts Output
SMALL OUTLINE PACKAGE
Features
• Improved Accuracy at High Temperature
• 1.5% Maximum Error over 0° to 85°C
MPXV6115VC6U
CASE 482A
• Ideally suited for Microprocessor or Microcontroller–Based Systems
• Temperature Compensated from – 40° to +125°C
• Durable Thermoplastic (PPS) Surface Mount Package
Application Examples
• Vacuum Pump Monitoring
• Brake Booster Monitoring
VS
THIN FILM
TEMPERATURE
COMPENSATION
AND
GAIN STAGE #1
SENSING
ELEMENT
PIN NUMBER
1
N/C
5
N/C
2
VS
Gnd
6
N/C
3
7
N/C
4
Vout
8
N/C
NOTE: Pins 1, 5, 6, 7, and 8 are internal device
connections. Do not connect to external circuitry
or ground. Pin 1 is denoted by the notch in the
lead.
GAIN STAGE #2
AND
GROUND
REFERENCE
SHIFT CIRCUITRY
Vout
PINS 1, 5, 6, 7 AND 8 ARE NO CONNECTS
GND
Figure 1. Fully Integrated Pressure Sensor
Schematic
REV 0
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MPXV6115VC6U
MAXIMUM RATINGS(1)
Parametrics
Symbol
Value
Units
Pmax
400
kPa
Tstg
–40° to +125°
°C
Operating Temperature
TA
–40° to +125°
°C
Output Source Current @ Full Scale Output(2)
Io+
0.5
mAdc
Output Sink Current @ Minimum Pressure Offset(2)
Io–
–0.5
mAdc
Maximum Pressure (P1
u P2)
Storage Temperature
NOTES:
1. Exposure beyond the specified limits may cause permanent damage or degradation to the device.
2. Maximum Output Current is controlled by effective impedance from Vout to Gnd or Vout to VS in the application circuit.
OPERATING CHARACTERISTICS (VS = 5.0 Vdc, TA = 25°C unless otherwise noted, P1
Characteristic
Min
Typ
Max
Unit
POP
–115
—
0
kPa
Supply Voltage(1)
VS
4.75
5.0
5.25
Vdc
Supply Current
Io
—
6.0
10
mAdc
Pressure Range
Freescale Semiconductor, Inc...
u P2.)
Symbol
Full Scale Output(2)
@ VS = 5.0 Volts
(0 to 85°C)
(Pdiff = 0 kPa)
VFSO
4.534
4.6
4.665
Vdc
Full Scale Span(3)
@ VS = 5.0 Volts
(0 to 85°C)
VFSS
—
4.4
—
Vdc
Accuracy(4)
(0 to 85°C)
—
—
—
±1.5
%VFSS
Sensitivity
V/P
—
38.26
—
mV/kPa
Response Time(5)
tR
—
1.0
—
ms
Warm–Up Time(6)
—
—
20
—
ms
Offset Stability(7)
—
—
± 0.5
—
%VFSS
NOTES:
1. Device is ratiometric within this specified excitation range.
2. Full Scale Output (VFSO) is defined as the output voltage at the maximum or full rated pressure.
3. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
4. Accuracy is the deviation in actual output from nominal output over the entire pressure range and temperature range as a percent of span
at 25°C due to all sources of error including the following:
• Linearity:
Output deviation from a straight line relationship with pressure over the specified pressure range.
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential
pressure applied.
• Pressure Hysteresis:
Output deviation at any pressure within the specified range, when this pressure is cycled to and from
minimum or maximum rated pressure at 25°C.
• TcSpan:
Output deviation over the temperature range of 0° to 85°C, relative to 25°C.
• TcOffset:
Output deviation with minimum pressure applied, over the temperature range of 0° to 85°C, relative
to 25°C.
5. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
6. Warm–up Time is defined as the time required for the product to meet the specified output voltage after the pressure has been stabilized.
7. Offset Stability is the product’s output deviation when subjected to 1000 cycles of Pulsed Pressure, Temperature Cycling with Bias Test.
3–184
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DIE
FLUOROSILICONE
GEL DIE COAT
MPXV6115VC6U
STAINLESS
STEEL CAP
P1
WIRE BOND
THERMOPLASTIC
CASE
LEAD
FRAME
+5.0 V
P2
DIE BOND
DIFFERENTIAL SENSING
ELEMENT
VS Pin 2
MPXV6115VC6U
100 nF
Vout Pin 4
to ADC
47 pF
GND Pin 3
51 K
Figure 3. Typical Application Circuit
(Output Source Current Operation)
Figure 2 illustrates the absolute sensing chip in the basic
Small Outline chip carrier (Case 482).
Figure 3 shows a typical application circuit (output source
current operation).
TRANSFER FUNCTION MPXV6115VC6U
5
OUTPUT (VOLTS)
Freescale Semiconductor, Inc...
Figure 2. Cross Sectional Diagram SOP
(Not to Scale)
TRANSFER FUNCTION:
4.5 V = V *[(0.007652*P) + 0.92] ± (Pressure error
out S
4 *Temp Factor*0.007652*VS)
VS = 5.0 V ± 0.25 Vdc
3.5
TEMP = 0–85° C
3
2.5
2
1.5
MAX
MIN
1
0.5
0
–115
–95
–75
–55
Vout vs. VACUUM
–35
–15
0
Figure 4. Output versus Absolute Pressure
Figure 4 shows the sensor output signal relative to pressure input. Typical minimum and maximum output curves
are shown for operation over 0 to 85°C temperature range.
The output will saturate outside of the rated pressure range.
A fluorosilicone gel isolates the die surface and wire
bonds from the environment, while allowing the pressure
signal to be transmitted to the silicon diaphragm. The
Motorola Sensor Device Data
MPXV6115VC6U pressure sensor operating characteristics,
internal reliability and qualification tests are based on use of
dry air as the pressure media. Media other than dry air may
have adverse effects on sensor performance and long–term
reliability. Contact the factory for information regarding media compatibility in your application.
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Freescale Semiconductor, Inc.
MPXV6115VC6U
Transfer Function (MPXV6115VC6U)
Nominal Transfer Value: Vout = VS x (0.007652 x P + 0.92)
± (Pressure Error x Temp. Factor x 0.007652 x VS)
VS = 5.0 ± 0.25 Vdc
Temperature Error Band
MPXV6115VC6U
4.0
Break Points
3.0
Temperature
Error
Factor
2.0
Temp
Multiplier
– 40
0 to 85
125
3
1
2
1.0
–40
–20
0
20
40
60
80
100
120
140
Temperature in C°
NOTE: The Temperature Multiplier is a linear response from 0°C to –40°C and from 85°C to 125°C
Pressure Error Band
Error Limits for Pressure
1.950
1.725
Pressure Error (kPa)
Freescale Semiconductor, Inc...
0.0
1.500
0
–115 –100
–85
–60
–45
–30
–15
Pressure in kPa
(below atmospheric)
0
–1.500
– 1.725
Pressure
– 1.950
–115 to 0 kPa
Error (Max)
"1.725 (kPa)
ORDERING INFORMATION — SMALL OUTLINE PACKAGE
Device Type
Ported Element
3–186
Options
Vacuum, Axial Port
Case No.
482A
MPX Series Order No.
MPXV6115VC6U
Packing Options
Rails
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Marking
MPXV6115V
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
MPXV6115VC6U
SURFACE MOUNTING INFORMATION
MINIMUM RECOMMENDED FOOTPRINT FOR SMALL OUTLINE PACKAGE
Surface mount board layout is a critical portion of the total
design. The footprint for the semiconductor package must
be the correct size to ensure proper solder connection interface between the board and the package. With the correct
pad geometry, the packages will self–align when subjected to
a solder reflow process. It is always recommended to fabricate boards with a solder mask layer to avoid bridging and/or
shorting between solder pads, especially on tight tolerances
and/or tight layouts.
0.100 TYP
2.54
Freescale Semiconductor, Inc...
0.660
16.76
0.060 TYP 8X
1.52
0.300
7.62
0.100 TYP 8X
2.54
inch
mm
Figure 5. SOP Footprint (Case 482A)
Motorola Sensor Device Data
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MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
AN935
Compensating for Nonlinearity in the MPX10
Series Pressure Transducer
Prepared by: Carl Demington
Design Engineering
Freescale Semiconductor, Inc...
INTRODUCTION
This application note describes a technique to improve the
linearity of Motorola’s MPX10 series (i.e., MPX10, MPXV10,
and MPX12 pressure sensors) pressure transducers when
they are interfaced to a microprocessor system. The
linearization technique allows the user to obtain both high
sensitivity and good linearity in a cost effective system.
The MPX10, MPXV10 and MPX12 pressure transducers
are semiconductor devices which give an electrical output
signal proportional to the applied pressure over the pressure
range of 0–10 kPa (0–75 mm Hg). These devices use a unique
transverse voltage–diffused silicon strain–gauge which is
sensitive to stress produced by pressure applied to a thin
silicon diaphragm.
One of the primary considerations when using a pressure
transducer is the linearity of the transfer function, since this
parameter has a direct effect on the total accuracy of the
system, and compensating for nonlinearities with peripheral
circuits is extremely complicated and expensive. The purpose
of this document is to outline the causes of nonlinearity, the
trade–offs that can be made for increased system accuracy,
and a relatively simple technique that can be utilized to
maintain system performance, as well as system accuracy.
ORIGINS OF NONLINEARITY
Nonlinearity in semiconductor strain–gauges is a topic that
has been the target of many experiments and much
discussion. Parameters such as resistor size and orientation,
surface impurity levels, oxide passivation thickness and
growth temperatures, diaphragm size and thickness are all
contributors to nonlinear behavior in silicon pressure
transducers. The Motorola X–ducer was designed to minimize
these effects. This goal was certainly accomplished in the
MPX2000 series which have a maximum nonlinearity of 0.1%
FS. However, to obtain the higher sensitivity of the MPX10
series, a maximum nonlinearity of ±1% FS has to be allowed.
The primary cause of the additional nonlinearity in the MPX10
series is due to the stress induced in the diaphragm by applied
pressure being no longer linear.
One of the basic assumptions in using semiconductor
strain–gauges as pressure sensors is that the deflection of the
diaphragm when pressure is applied is small compared to the
thickness of the diaphragm. With devices that are very
sensitive in the low pressure ranges, this assumption is no
longer valid. The deflection of the diaphragm is a considerable
percentage of the diaphragm thickness, especially in devices
with higher sensitivities (thinner diaphragms). The resulting
stresses do not vary linearly with applied pressure. This
behavior can be reduced somewhat by increasing the area of
the diaphragm and consequently thickening the diaphragm.
Due to the constraint, the device is required to have high
sensitivity over a fairly small pressure range, and the
nonlinearity cannot be eliminated. Much care was given in the
design of the MPX10 series to minimize the nonlinear
behavior. However, for systems which require greater
accuracy, external techniques must be used to account for this
behavior.
PERFORMANCE OF AN MPX DEVICE
The output versus pressure of a typical MPX12 along with
an end–point straight line is shown in Figure 1. All nonlinearity
errors are referenced to the end–point straight line (see data
sheet). Notice there is an appreciable deviation from the
end–point straight line at midscale pressure. This shape of
curve is consistent with MPX10 and MPXV10, as well as
MPX12 devices, with the differences between the parts being
the magnitude of the deviation from the end–point line. The
major tradeoff that can be made in the total device
performance is sensitivity versus linearity.
Figure 2 shows the relationship between full scale span and
nonlinearity error for the MPX10 series of devices. The data
shows the primary contribution to nonlinearity is
nonproportional stress with pressure, while assembly and
packaging stress (scatter of the data about the line) is fairly
small and well controlled. It can be seen that relatively good
accuracies (<0.5% FS) can be achieved at the expense of
reduced sensitivity, and for high sensitivity the nonlinearity
errors increase rapidly. The data shown in Figure 2 was taken
at room temperature with a constant voltage excitation of
3.0 volts.
REV 3
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90
0.5
0.4
0.3
0.2
0.1
80
60
50
B0
Vout (mV)
70
40
30
20
10
0
0
10
20
30
40
50
60
70
80
90
0
– 0.1
– 0.2
– 0.3
– 0.4
– 0.5
20
25
30
35
40
45
50
55
60
65
70
SPAN (mV)
Figure 1. MPX12 Linearity Analysis Raw Data
Figure 3. MPX10 Linearity Analysis —
Correlation of B0 Vout = B0 + B1 (P) + B2 (P)2
1.1
1.0
4.0
B1 = 0.2055 + 1.598E – 3*(SPAN)
+ 1.723E – 4*(SPAN)2
0.9
0.8
3.0
B1
LINEARITY (% FS)
2.0
0.7
0.6
0.5
1.0
0.4
0
0
10
20
30
40
50
60
70
80
0.3
0.2
20
90
25
30
35
40
45
50
55
60
65
70
SPAN (mV)
SPAN (mV)
Figure 4. MPX10 Linearity Analysis —
Correlation of B1 Vout = B0 + B1 (P) + B2 (P)2
Figure 2. MPX10 Series Span versus Linearity
0.0030
COMPENSATION FOR NONLINEARITY
The nonlinearity error shown in Figure 1 arises from the
assumption that the output voltage changes with respect to
pressure in the following manner:
Vout = Voff + sens*P
where Voff = output voltage at zero pressure
differential
sens = sensitivity of the device
P = applied pressure
[1]
0.0015
0.0005
[2]
where B0, B1, B2, B3, etc. are sensitivity coefficients. In
order to determine the sensitivity coefficients given in equation
[2] for the MPX10 series of pressure transducers, a polynomial
regression analysis was performed on data taken from 139
devices with full scale spans ranging from 30 to 730 mV. It was
found that second order terms are sufficient to give excellent
agreement with experimental data. The calculated regression
coefficients were typically 0.999999+ with the worst case
being 0.99999. However, these sensitivity coefficients
demonstrated a strong correlation with the full scale span of
the device for which they were calculated. The correlation of
B0, B1, and B2 with full scale span is shown in Figures 3
through 5.
Motorola Sensor Device Data
B2 = –1.293E – 13*(SPAN)5.68
0.0020
0.0010
It is obvious that the true output does not follow this simple
straight line equation. Therefore, if an expression could be
determined with additional higher order terms that more
closely described the output behavior, increased accuracies
would be possible. The output expression would then become
Vout = Voff +(B0+B1*P+B2*P2+B3*P3 +. . .)
0.0025
–B 2
Freescale Semiconductor, Inc...
B0 = 0.1045 – 0.00295*(SPAN)
PRESSURE (torr)
5.0
–1.0
AN935
20
25
30
35
40
45
50
55
60
65
70
SPAN (mV)
Figure 5. MPX10 Linearity Analysis —
Correlation of B2 Vout = B0 + B1 (P) + B2 (P)2
In order to simplify the determination of these coefficients
for the user, further regression analysis was performed so that
expressions could be given for each coefficient as a function
of full scale span. This would then allow the user to do a single
pressure measurement, a series of calculations, and
analytically arrive at the equation of the line that describes the
output behavior of the transducer. Nonlinearity errors were
then calculated by comparing experimental data with the
values calculated using equation [2] and the sensitivity
coefficients given by the regression analysis. The resulting
errors are shown in Figures 6 through 9 at various pressure
points. While using this technique has been successful in
reducing the errors due to nonlinearity, the considerable
spread and large number of devices that showed errors >1%
indicate this technique was not as successful as desired.
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Freescale Semiconductor, Inc.
AN935
%
21.54
NO. OF UNITS
LINEARITY ERROR (% FS)
30
19.38
27
24
Freescale Semiconductor, Inc...
21
17.23
General Fit
P = 1/4 FS
Average Error = 0.15
Standard Deviation = 0.212
15.08
18
12.92
15
10.77
12
8.62
9.0
6.46
6.0
4.31
3.0
2.15
0.0
– 2.0 –1.8 –1.6 –1.4 –1.2 –1.0 – 0.8 – 0.6 – 0.4 – 0.2 0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Figure 6. Linearity Error of General Fit Equation at 1/4 FS
%
16.15
NO. OF UNITS
LINEARITY ERROR (% FS)
14.54
21
12.92
18
15
General Fit
P = 1/2 FS
Average Error = – 0.02
Standard Deviation = 0.391
11.31
9.69
12
8.08
6.46
9.0
4.85
6.0
3.23
3.0
1.62
0.0
– 2.0 –1.8 –1.6 –1.4 –1.2 –1.0 – 0.8 – 0.6 – 0.4 – 0.2 0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Figure 7. Linearity Error of General Fit Equation at 1/2 FS
3–190
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AN935
NO. OF UNITS
%
12.31
LINEARITY ERROR (% FS)
16.5
11.08
15
13.5
12
9.85
General Fit
P = 3/4 FS
Average Error = – 0.10
Standard Deviation = 0.549
8.62
10.5
7.38
9.0
6.15
Freescale Semiconductor, Inc...
7.5
4.92
6.0
3.69
4.5
2.46
3.0
1.23
1.5
0.0
– 2.0 –1.8 –1.6 –1.4 –1.2 –1.0 – 0.8 – 0.6 – 0.4 – 0.2
0.0 0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Figure 8. Linearity Error of General Fit Equation at 3/4 FS
NO. OF UNITS
19.5
%
13.85
LINEARITY ERROR (% FS)
12.46
18
16.5
15
13.5
11.08
General Fit
P = 1 FS
Average Error = 0.11
Standard Deviation = 0.809
9.69
12
8.31
10.5
6.92
9.0
5.54
7.5
4.15
6.0
4.5
2.77
3.0
1.38
1.5
0.0
– 2.0 –1.8 –1.6 –1.4 –1.2 –1.0 – 0.8 – 0.6 – 0.4 – 0.2 0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Figure 9. Linearity Error of General Fit Equation at FS
Motorola Sensor Device Data
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AN935
devices having errors <0.5%, while only one of the devices
was >1%. The sensitivity coefficients that are substituted into
equation [2] for the different techniques are given in Table 1.
It is important to note that for either technique the only
measurement that is required by the user in order to clearly
determine the sensitivity coefficients is the determination of
the full scale span of the particular pressure transducer.
A second technique that still uses a single pressure
measurement as the input was investigated. In this method,
the sensitivity coefficients are calculated using a piece–wise
linearization technique where the total span variation is
divided into four windows of 10 mV (i.e., 30–39.99, 40–49.99,
etc.) and coefficients calculated for each window. The errors
that arise out of using this method are shown in Figures 10
through 13. This method results in a large majority of the
NO. OF UNITS
%
37.69
LINEARITY ERROR (% FS)
33.92
48
Freescale Semiconductor, Inc...
42
36
30.15
General Fit
P = 1/4 FS
Average Error = 0.18
Standard Deviation = 0.159
26.38
22.62
30
18.85
24
15.08
18
11.31
12
7.54
6.0
3.77
0.0
– 2.0 –1.8 –1.6 –1.4 –1.2 –1.0 – 0.8 – 0.6 – 0.4 – 0.2 0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4 1.6
1.8
2.0
Figure 10. Linearity Error of Piece–Wise Linear Fit at 1/4 FS
Table 1. Comparison of Linearization Methods
SPAN WINDOW
B0
B1
B2
GENERAL FIT
0.1045 + 2.95E – 3X
0.2055 + 1.598E – 3X + 1.723E – 4X2
1.293E – 13X5.681
PIECE–WISE LINEAR FIT
30–39.99
0.08209 – 2.246E – 3X
40–49.99
0.1803 – 4.67E – 3X
–0.119 + 1.655E – 2X
–1.572E – 3 + 4.247E – 5X
50–59.99
0.1055 – 3.051E – 3X
–0.355 + 2.126E – 2X
–5.0813 – 3 + 1.116E – 4X
–0.361 + 2.145E – 2X
–5.928E – 3 + 1.259E – 4X
60–69.99
–0.288 + 3.473E – 3X
0.02433 = 1.430E – 2X
–1.961E – 4 + 8.816E – 6X
X = Full Scale Span
3–192
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AN935
%
20
NO. OF UNITS
LINEARITY ERROR (% FS)
27
18
24
21
Freescale Semiconductor, Inc...
18
16
General Fit
P = 1/2 FS
Average Error = 0.02
Standard Deviation = 0.267
14
12
15
10
12
8.0
9.0
6.0
6.0
4.0
3.0
2.0
0.0
– 2.0 –1.8 –1.6 –1.4 –1.2 –1.0 – 0.8 – 0.6 – 0.4 – 0.2 0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4 1.6
1.8
2.0
Figure 11. Linearity Error of Piece–Wise Linear Fit at 1/2 FS
NO. OF UNITS
%
16.15
LINEARITY ERROR (% FS)
21
18
15
14.54
12.92
General Fit
P = 3/4 FS
Average Error = – 0.09
Standard Deviation = 0.257
11.31
9.69
12
8.08
9.0
6.46
4.85
6.0
3.23
3.0
1.62
0.0
– 2.0 –1.8 –1.6 –1.4 –1.2 –1.0 – 0.8 – 0.6 – 0.4 – 0.2 0.0
0.2
0.4
0.6
0.8
1.0 1.2
1.4
1.6
1.8
2.0
Figure 12. Linearity Error of Piece–Wise Linear Fit at 3/4 PS
Motorola Sensor Device Data
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AN935
NO. OF UNITS
%
38.46
LINEARITY ERROR (% FS)
52.5
34.62
45
37.5
30.77
General Fit
P = 1 FS
Average Error = 0.13
Standard Deviation = 0.186
26.92
23.08
30
19.23
Freescale Semiconductor, Inc...
22.5
15.38
11.54
15
7.69
7.5
3.85
0.0
– 2.0 –1.8 –1.6 –1.4 –1.2 –1.0 – 0.8 – 0.6 – 0.4 – 0.2 0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Figure 13. Linearity Error of Piece–Wise Linear Fit at FS
Once the sensitivity coefficients have been determined, a
system can then be built that provides an accurate output
function with pressure. The system shown in Figure 14
consists of a pressure transducer, a temperature
compensation and amplification stage, an A/D converter, a
microprocessor, and a display. The display block can be
replaced with a control function if required. The A/D converter
simply transforms the voltage signal to an input signal for the
microprocessor, in which resides the look–up table of the
transfer function generated from the previously determined
sensitivity coefficients. The microprocessor can then drive a
display or control circuit using standard techniques.
X–DUCER
DISPLAY
MICROCONTROLLER
MC68HC908QT4
TEMPERATURE
COMPENSATION
AND AMPLIFICATION
Figure 14. Linearization System Block Diagram
SUMMARY
While at first glance this technique appears to be fairly
complicated, it can be a very cost effective method of building
a high–accuracy, high–sensitivity pressure–monitoring
system for low–pressure ranges.
3–194
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MOTOROLA
SEMICONDUCTOR APPLICATION NOTE
AN936
Mounting Techniques, Lead Forming and
Testing of Motorola's MPX Series Pressure Sensors
Prepared by: Randy Frank
Motorola Inc., Semiconductor Products Sector
Phoenix, Arizona
Freescale Semiconductor, Inc...
INTRODUCTION
Motorola’s MPX series pressure sensors are silicon
piezoresistive strain–gauges offered in a chip–carrier
package (see Figure 1). The exclusive chip–carrier package
was developed to realize the advantages of high–speed,
automated assembly and testing. In addition to high volume
availability and low cost, the chip–carrier package offers users
a number of packaging options. This Application Note
describes several mounting techniques, offers lead forming
recommendations, and suggests means of testing the MPX
series of pressure sensors.
DIFFERENTIAL
PORT OPTION
CASE 344C–01
Figure 1. MPX Pressure Sensor In Chip Carrier
Package Shown with Port Options
BASIC ELEMENT
CASE 344–15
SUFFIX A / D
GAUGE PORT
CASE 344B–01
SUFFIX AP / GP
AXIAL VACUUM PORT STOVEPIPE VACUUM PORT
CASE 344G–01
CASE 344E–01
SUFFIX GVSX
SUFFIX AS/GS
DUAL PORT
CASE 867C–05
SUFFIX DP
AXIAL PORT
CASE 867F–03
SUFFIX ASX / GSX
GAUGE VACUUM PORT
CASE 344D–01
SUFFIX GVP
STOVEPIPE PORT
CASE 344A–01
SUFFIX GVS
BASIC ELEMENT
CASE 867–08
SUFFIX A / D
AXIAL VACUUM PORT
CASE 867G–03
SUFFIX GVSX
DUAL PORT
CASE 344C–01
SUFFIX DP
GAUGE PORT
CASE 867B–04
SUFFIX AP / GP
STOVEPIPE PORT
CASE 867E–03
SUFFIX AS / GS
AXIAL PORT
CASE 344F–01
SUFFIX ASX / GSX
GAUGE VACUUM PORT
CASE 867D–04
SUFFIX GVP
STOVEPIPE VACUUM PORT
CASE 867A–04
SUFFIX GVS
Figure 2. Chip Carrier and Available Ported Packages
REV 3
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AN936
PORT ADAPTERS
Freescale Semiconductor, Inc...
Available Packages
Motorola’s chip–carrier package and available ports for
attachment of 1/8″ I.D. hose are made from a high
temperature thermoplastic that can withstand temperature
extremes from –50 to 150°C (see Figure 2). The port adapters
were designed for rivet or 5/32″ screw attachment to panels,
printed circuit boards or chassis mounting.
Custom Port Adaptor Installation Techniques
The Motorola MPX silicon pressure sensor is available in a
basic chip carrier cell which is adaptable for attachment to
customer specific housings/ports (Case 344 for 4–pin devices
and Case 867 for 6–pin devices). The basic cell has
chamfered shoulders on both sides which will accept an
O–ring such as Parker Seal’s silicone O–ring
(p/n#2–015–S–469–40).
Refer to Figure 3 for the
recommended O–ring to sensor cell interface dimensions.
The sensor cell may also be glued directly to a custom
housing or port using many commercial grade epoxies or RTV
adhesives which adhere to grade Valox 420, 30% glass
reinforced polyester resin plastic or Union Carbide’s Udel
polysulfone (MPX2300DT1 only). Motorola recommends
using Thermoset EP530 epoxy or an equivalent. The epoxy
should be dispensed in a continuous bead around the
case–to–port interface shoulder. Refer to Figure 4. Care must
be taken to avoid gaps or voids in the adhesive bead to help
ensure that a complete seal is made when the cell is joined to
the port. The recommended cure conditions for Thermoset
EP539 are 15 minutes at 150°C. After cure, a simple test for
gross leaks should be performed to ensure the integrity of the
.114
.047
cell to port bond. Submerging the device in water for 5
seconds with full rated pressure applied to the port nozzle and
checking for air bubbles will provide a good indication.
TESTING MPX SERIES PRESSURE SENSORS
Pressure Connection
Testing of pressure sensing elements in the chip carrier
package can be performed easily by using a clamping fixture
which has an O–ring seal to attach to the beveled surface.
Figure 8 shows a diagram of the fixture that Motorola uses to
apply pressure or vacuum to unported elements.
When performing tests on packages with ports, a high
durometer tubing is necessary to minimize leaks, especially in
higher pressure range sensors. Removal of tubing must be
parallel to the port since large forces can be generated to the
pressure port which can break the nozzle if applied at an
angle. Whether sensors are tested with or without ports, care
must be exercised so that force is not applied to the back metal
cap or offset errors can result.
Standard Port Attach Connection
Motorola also offers standard port options designed to
accept readily available silicone, vinyl, nylon or polyethylene
tubing for the pressure connection. The inside dimension of
the tubing selected should provide a snug fit over the port
nozzle. Installation and removal of tubing from the port nozzle
must be parallel to the nozzle to avoid undue stress which may
break the nozzle from the port base. Whether sensors are
used with Motorola’s standard ports or customer specific
housings, care must be taken to ensure that force is uniformly
distributed to the package or offset errors may be induced.
0
.125
ADHESIVE BEAD
.075
.037R
0
.210″
CELL
.021
Figure 3. Examples of Motorola Sensors
in Custom Housings
3–196
Figure 4. Case to Port Interface
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5.72
0.225
= DIAMETER
MM
DIMENSIONS IN INCHES
AN936
F
4.55
0.179
3.81
0.150
3.40
0.134
2.54
0.100
2.39
0.094
φ 0.36 (0.014)
1.27
0.050
φ 0.36 (0.014)
M
A B
A B
M
C
M
C
M
M
0.76
0.030
M
10.16
0.400
2.03 3 PL
0.080
14.48
0.570
3.96
0.156
16.23
0.639
Freescale Semiconductor, Inc...
1.60
0.063
35° ± 2°
6.35
0.250
3.96
0.156
6.35
0.250
13.66
13.51
0.538
0.532
F
2.21
2.13
0.087
SECTION F–F 0.084
φ 0.36 (0.014)
M
A B
M
C
M
2 PL
0.36 (0.014) A B C
ZONE –D– WITHIN
ZONE –D–
Figure 5. Port Adapter Dimensions
C
R
M
B
–A–
TOP CLAMP AREA
N
1
PIN 1
2
3
L
4
–T–
SEATING
PLANE
J
G
F
D
4 PL
0.136 (0.005)
M
T A
M
NOTES:
1. DIMENSIONING AND TOLERANCING PER ASME
Y14.5M, 1994.
2. CONTROLLING DIMENSION: INCH.
3. DIMENSION –A– IS INCLUSIVE OF THE MOLD
STOP RING. MOLD STOP RING NOT TO EXCEED
16.00 (0.630).
DIM
A
B
C
D
F
G
J
L
M
N
R
INCHES
MIN
MAX
0.595
0.630
0.514
0.534
0.200
0.220
0.016
0.020
0.048
0.064
0.100 BSC
0.014
0.016
0.695
0.725
30_ NOM
0.475
0.495
0.430
0.450
STYLE 1:
PIN 1.
2.
3.
4.
GROUND
+ OUTPUT
+ SUPPLY
– OUTPUT
MILLIMETERS
MIN
MAX
15.11
16.00
13.06
13.56
5.08
5.59
0.41
0.51
1.22
1.63
2.54 BSC
0.36
0.40
17.65
18.42
30 _ NOM
12.07
12.57
10.92
11.43
BOTTOM CLAMP AREA
Leads should be securely clamped top and
bottom in the area between the plastic body
and the form being sure that no stress is being
put on plastic body. The area between dotted
lines represents surfaces to be clamped.
CASE 344–15
All seals to be made on pressure sealing surface.
Figure 6. Chip–Carrier Package
Motorola Sensor Device Data
Figure 7. Leadforming
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AN936
Freescale Semiconductor, Inc.
Electrical Connection
The MPX series pressure sensor is designed to be installed
on a printed circuit board (standard 0.100″ lead spacing) or to
accept an appropriate connector if installed on a baseplate.
The leads of the sensor may be formed at right angles for
assembly to the circuit board, but one must ensure that proper
leadform techniques and tools are employed. Hand or
“needlenose” pliers should never be used for leadforming
unless they are specifically designed for that purpose. Refer
to Figure 7 for the recommended leadform technique. It is also
important that once the leads are formed, they should not be
straightened and reformed without expecting reduced
durability. The recommended connector for off–circuit board
applications
may
be
supplied
by
JST
Corp.
(1–800–292–4243) in Mount Prospect, IL. The part numbers
for the housing and pins are listed below.
CONCLUSION
Motorola’s MPX series pressure sensors in the chip carrier
package provide the design engineer several packaging
alternatives. They can easily be tested with or without
pressure ports using the information provided.
Freescale Semiconductor, Inc...
CONNECTORS FOR CHIP CARRIER PACKAGES
MFG./ADDRESS/PHONE
CONNECTOR
PIN
J.S. Terminal Corp.
1200 Business Center Dr.
Mount Prospect, IL 60056
(800) 292–4243
4 Pin Housing: SMP–04V–BC
6 Pin Housing: SMP–06V–BC
SHF–001T–0.8SS
SHF–01T–0.8SS
Methode Electronics, Inc.
Rolling Meadows, IL 60008
(312) 392–3500
1300–004
Hand crimper YC–12 recommended
Requires hand crimper
1400–213
1402–213
1402–214 Reel
TERMINAL BLOCKS
Molex
2222 Wellington Court
Lisle, IL 60532
(312) 969–4550
22–18–2043
22–16–2041
Samtec
P.O. Box 1147
New Albany, IN 47150
(812) 944–6733
SSW–104–02–G–S–RA
SSW–104–02–G–S
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Motorola Sensor Device Data
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AN936
A 0.002
0.175 ±0.001
0.01 x 45°
4 PL
For Vacuum
or Pressure
Source
–A–
0.125 Dia.
Freescale Semiconductor, Inc...
±0.000
0.311 –0.001
Dia.
±0.002
0.290 Dia.
0.070 Dia.
0.130 ±0.002
0.10
For Retaining Ring
(Waldes Kohinoor Inc.
Truarc 5100–31)
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
0.036
R
0.038
/ A 0.002 TOTAL
30°
0.44 Dia.
0.648
0.650
Dia.
0.575 Dia.
0.780 Dia.
±0.002
0.670 Dia.
0.015 R
0.02 R
0.04
For O–Ring
(Parker Seals
2–015–S469–40)
0.250
0.245
+0.003
–0.000
0.60
0.525–
1.00
1.25 Ref
A
0.0005
Figure 8. O–Ring Test Fixture
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MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
AN1082
Simple Design for a 4-20 mA Transmitter
Interface Using a Motorola Pressure Sensor
Prepared by: Jean Claude Hamelain
Motorola Toulouse Application Lab Manager
Freescale Semiconductor, Inc...
INTRODUCTION
Pressure is a very important parameter in most industrial
applications such as air conditioning, liquid level sensing and
flow control.
In most cases, the sensor is located close to the measured
source in a very noisy environment, far away from the receiver
(recorder, computer, automatic controller, etc.)
The transmission line can be as long as a few hundred
meters and is subject to electromagnetic noise when the
signal is transmitted as voltage. If the signal is transmitted as
a current it is easier to recover at the receiving end and is less
affected by the length of the transmission line.
The purpose of this note is to describe a simple circuit which
can achieve high performance, using standard Motorola
pressure sensors, operational amplifiers and discrete
devices.
PERFORMANCES
The following performances have been achieved using an
MPXV2102DP Motorola pressure sensor and an MC33079
quad operational amplifier. The MPXV2102DP is a 100 kPa
temperature compensated differential pressure sensor. The
load is a 150 ohm resistor at the end of a 50 meter telephone
line. The 15 volt power supply is connected at the receiver
end.
Power Supply
+15 Vdc, 30 mA
Connecting Line
3 wire telephone cable
Load Resistance
150 to 400 Ohms
Temperature Range
– 40 to + 85°C (up to +125°C
with special hardware)
Pressure Range
0 to 100 kPa
Total Maximum Error
Better than 2% full scale
Basic Circuit
The Motorola MPXV2102DP pressure sensor is a very high
performance piezoresistive pressure sensor. Manufacturing
technologies include standard bipolar processing techniques
with state of the art metallization and on–chip laser trim for
offset and temperature compensation.
This unique design, coupled with computer laser trimming,
gives this device excellent performance at competitive cost
for demanding applications such as automotive, industrial or
healthcare.
MC33078, 79 operational amplifiers are specially designed
for very low input voltage, a high output voltage swing and very
good stability versus temperature changes.
First Stage
The Motorola MPXV2102 and the operational amplifier are
directly powered by the 15 Vdc source. The first stage is a
simple true differential amplifier made with both of the
operational amplifiers in the MC33078. The potentiometer,
RG, provides adjustment for the output.
Current Generator
The voltage to current conversion is made with a unity gain
differential amplifier, one of the four operational amplifiers in
an MC33079. The two output connections from the first stage
are connected to the input of this amplifier through R3 and R5.
Good linearity is achieved by the matching between R3, R4,
R5 and R6, providing a good common mode rejection. For the
same reason, a good match between resistors R8 and R9 is
needed.
The MC33078 or MC33079 has a limited current output;
therefore, a 2N2222 general purpose transistor is connected
as the actual output current source to provide a 20 mA output.
To achieve good performance with a very long transmission
line it may be necessary to place some capacitors (C1, C2)
between the power supply and output to prevent oscillations.
Calibration
The circuit is electrically connected to the 15 Vdc power
supply and to the load resistor (receiver).
The high pressure is connected to the pressure port and the
low pressure (if using a differential pressure sensor), is
connected to the vacuum port.
It is important to perform the calibration with the actual
transmission line connected.
The circuit needs only two adjustments to achieve the
4 – 20 mA output current.
1. With no pressure (zero differential pressure), adjust Roff
to read exactly 4 mA on the receiver.
2. Under the full scale pressure, adjust RG to exactly read
20 mA on the receiver. The calibration is now complete.
REV 2
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AN1082
VCC = +15 Volts dc
3
RG
3
2
MPX2100DP
1
4
gain
adj.
+ 8
a1
–
R1
2
C1
C2
R4
1
R3
+
+
a3
–
output
6
R2
–
a2
7
+
4
5
–
R5
Remote
Receiver
2N2222
R8
RL
R9
R7
R6
Roff
R10
R11
Freescale Semiconductor, Inc...
R12
OFFSET ADJUST
Basic Circuit of SEK–1
RG = 47 K Pot. R7 = 1 K
Roff = 1 M Pot. R10 = 110 K
* R1 = R2 = 330 K R11 = 1 M
* R3 = R4 = 27 K R12 = 330 K
* R5 = R6 = 27 K C1 = C2 = 0.1 µF
* R8 = R9 = 150 a1, a2, a3 = 1/4 MC33079
* All resistor pairs must be matched at better than 0.5%
Additional Circuit for 4 to 20 mA current loop
(Receiver Load Resistance : RL = 150 to 400 Ohms)
Note A: If using SEK–1 a1, a2, a3 = 1/2 MC33078
Note A: RG from 20 K to 47 K
Note A: R1 and R2 from 1M to 330 K
NOTICE: THE PRESSURE SENSOR OUTPUT IS RATIOMETRIC TO THE POWER SUPPLY
VOLTAGE. THE OUTPUT WILL CHANGE WITH THE SAME RATIO AS VOLTAGE CHANGE.
Figure 1. Demo Kit with 4 – 20 mA Current Loop
The output is ratiometric to the power supply voltage. For
example, if the receiver reads 18 mA at 80 kPa and 15 V power
supply, the receiver should read 16.8 mA under the same
pressure with 14 V power supply.
For best results it is mandatory to use a regulated power
supply. If that is not possible, the circuit must be modified by
inserting a 12 V regulator to provide a constant supply to the
pressure sensor.
When using a Motorola MC78L12AC voltage regulator, the
circuit can be used with power voltage variation from 14 to
30 volts.
The following results have been achieved using an
Motorola Sensor Device Data
MPX2100DP and two MC33078s. The resistors were regular
carbon resistors, but pairs were matched at ± 0.3% and
capacitors were 0.1 µF. The load was 150 ohms and the
transmission line was a two pair telephone line with the
+15 Vdc power supply connected on the remote receiver
side.
Note: Best performances in temperature can be achieved
using metal film resistors. The two potentiometers must be
chosen for high temperatures up to 125°C.
The complete circuit with pressure sensor is available
under reference TZA120 and can be ordered as a regular
Motorola product for evaluation.
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AN1082
22
21
+
20
19
+
+
18
+
17
16
Io (OUTPUT mA)
15
+
14
13
12
11
+
10
9
+
7
+
6
4
Power supply + 15 V dc, 150 Ohm load
+
5
85°
+ 25°
0°
– 40°
+
3
0
20
40
60
80
100
PRESSURE (kPa)
Figure 2. Output versus Pressure
2.0
1.5
1.0
.5
ERROR (kPA)
Freescale Semiconductor, Inc...
8
0
+
+
+
+
+
+
+
+
+
+
– .5
– 1.0
Reference algorithm Io(mA) = 4 + 16 x P(kPa)
– 1.5
85°
+ 25°
0°
– 40°
– 2.0
0
20
40
60
80
100
PRESSURE (kPa)
Reference algorithm is the straight from output at 255 0 pressure and output at full pressure
Figure 3. Absolute Error Reference to Algorithm
3–202
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Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
Calibration-Free Pressure Sensor System
AN1097
Prepared by: Michel Burri, Senior System Engineer
Geneva, Switzerland
Freescale Semiconductor, Inc...
INTRODUCTION
The MPX2000 series pressure transducers are
semiconductor devices which give an electrical output signal
proportional to the applied pressure. The sensors are a single
monolithic silicon diaphragm with strain gauge and thin–film
resistor networks on the chip. Each chip is laser trimmed for
full scale output, offset, and temperature compensation.
The purpose of this document is to describe another method
of measurement which should facilitate the life of the designer.
The MPX2000 series sensors are available both as unported
elements and as ported assemblies suitable for pressure,
vacuum and differential pressure measurements in the range
of 10 kPa through 200 kPa.
The use of the on–chip A/D converter of Motorola’s
MC68HC05B6 HCMOS MCU makes possible the design of
an accurate and reliable pressure measurement system.
SYSTEM ANALYSIS
The measurement system is made up of the pressure
sensor, the amplifiers, and the MCU. Each element in the
chain has its own device–to–device variations and
temperature effects which should be analyzed separately. For
instance, the 8–bit A/D converter has a quantization error of
about ± 0.2%. This error should be subtracted from the
maximum error specified for the system to find the available
error for the rest of elements in the chain. The MPX2000 series
pressure sensors are designed to provide an output sensitivity
of 4.0 mV/V excitation voltage with full–scale pressure applied
or 20 mV at the excitation voltage of 5.0 Vdc.
An interesting property must be considered to define the
configuration of the system: the ratiometric function of both the
A/D converter and the pressure sensor device. The
ratiometric function of these elements makes all voltage
variations from the power supply rejected by the system. With
this advantage, it is possible to design a chain of amplification
where the signal is conditioned in a different way.
Ç
ÇÇÇ Ç
ÇÇ
ÇÇ
Ç
ÇÇ
ÇÇ
ÇÇÇÇ
ÇÇ Ç
ÇÇ Ç
ÇÇ
+ Vs
PIN 3
Rs1
Rp
Rin
THERMISTOR
Rs2
LASER
TRIMMED
ON–CHIP
PIN 1
PIN 2
+
Vout
–
PIN 4
GND
Figure 1. Seven Laser–Trimmed Resistors and Two
Thermistors Calibrate the Sensor for Offset, Span,
Symmetry and Temperature Compensation
The op amp configuration should have a good
common–mode rejection ratio to cancel the DC component
voltage of the pressure sensor element which is about half the
excitation voltage value VS. Also, the op amp configuration is
important when the designer’s objective is to minimize the
calibration procedures which cost time and money and often
don’t allow the unit–to–unit replacement of devices or modules.
One other aspect is that most of the applications are not
affected by inaccuracy in the region 0 kPa thru 40 kPa.
Therefore, the goal is to obtain an acceptable tolerance of the
system from 40 kPa through 100 kPa, thus minimizing the
inherent offset voltage of the pressure sensor.
REV 1
Motorola Sensor Device Data
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AN1097
PRESSURE SENSOR CHARACTERISTICS
OP AMP CHARACTERISTICS
Figure 2 shows the differential output voltage of the
MPX2100 series at +25°C. The dispersion of the output
voltage determines the best tolerance that the system may
achieve without undertaking a calibration procedure, if any
other elements or parameters in the chain do not introduce
additional errors.
For systems with only one power supply, the instrument
amplifier configuration shown in Figure 4 is a good solution to
monitor the output of a resistive transducer bridge.
The instrument amplifier does provide an excellent CMRR
and a symmetrical buffered high input impedance at both
non–inverting and inverting terminals. It minimizes the
number of the external passive components used to set the
gain of the amplifier. Also, it is easy to compensate the
temperature variation of the Full Scale Output of the Pressure
Sensor by implementing resistors “Rf” having a negative
coefficient temperature of –250 PPM/°C.
The differential–mode voltage gain of the instrument
amplifier is:
Vout (mV)
20
VS = 5 Vdc
TA = 25°C
FULL–SCALE
Freescale Semiconductor, Inc...
10
Avd =
V1–V2
2 Rf
= 1+
Vs2–Vs4
Rg
(1)
5
OFFSET
0
+Vs
–5
0
20
40
60
80
100
P
(kPa)
Figure 2. Spread of the Output Voltage versus the
Applied Pressure at 25°C
The effects of temperature on the full scale output and offset
are shown in Figure 3. It is interesting to notice that the offset
variation is greater than the full scale output and both have a
positive temperature coefficient respectively of +8.0
µV/degree and +5.0 µV excitation voltage. That means that
the full scale variation may be compensated by modifying the
gain somewhere in the chain amplifier by components
arranged to produce a negative TC of 250 PPM/°C. The dark
area of Figure 3 shows the trend of the compensation which
improves the full scale value over the temperature range. In
the area of 40 kPa, the compensation acts in the ratio of
40/100 of the value of the offset temperature coefficient.
Vout (f) ∆T
+85°C
POSITIVE
FULL SCALE
VARIATION
–15°C
OFFSET VARIATION
0
20
40
60
80
100
+
ÉÉÉ
ÉÉÉÉ
ÉÉÉÉ
ÉÉÉ
–
3
2
Rg
4
1
V1
Rf
–
+
V2
0V
Figure 4. One Power Supply to Excite the Bridge
and to Develop a Differential Output Voltage
The major source of errors introduced by the op amp is
offset voltages which may be positive or negative, and the
input bias current which develops a drop voltage ∆V through
the feedback resistance Rf. When the op amp input is
composed of PNP transistors, the whole characteristic of the
transfer function is shifted below the DC component voltage
value set by the Pressure Sensor as shown in Figure 5.
The gain of the instrument amplifier is calculated carefully
to avoid a saturation of the output voltage, and to provide the
maximum of differential output voltage available for the A/D
Converter. The maximum output swing voltage of the
amplifiers is also dependent on the bias current which creates
a ∆V voltage on the feedback resistance Rf and on the Full
Scale output voltage of the pressure sensor.
P
(kPa)
Figure 3. Output Voltage versus Temperature. The
Dark Area Shows the Trend of the Compensation
3–204
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AN1097
lib (nA)
V1, V2
5 Vdc
VCC
600
450
UNIT 1
V1
V2X
1/2
VCC
0
5
150
V1X
V2
VEE
UNIT 2
300
10
15
20
0
VPS
(mV)
–50
–25
0
25
50
75
100
125
T
(°C)
Freescale Semiconductor, Inc...
Figure 7. Input Bias Current versus Temperature
Figure 5. Instrument Amplifier Transfer Function with
Spread of the Device to Device Offset Variation
Figure 5 shows the transfer function of different instrument
amplifiers used in the same application. The same sort of
random errors are generated by crossing the inputs of the
instrument amplifier. The spread of the differential output
voltage (V1–V2) and (V2x–V1x) is due to the unsigned voltage
offset and its absolute value. Figures 6 and 7 show the
unit–to–unit variations of both the offset and the bias current
of the dual op amp MC33078.
MCU CONTRIBUTION
As shown in Figure 5, crossing the instrument amplifier
inputs generated their mutual differences which can be
computed by the MCU.
+VS
+
3
2
Rg
Vio (mV)
4
+2
V1
–
1
ÉÉ
ÉÉ
Rf
–
V2
+
UNIT 1
P
+1
0V
UNIT 2
Figure 8. Crossing of the Instrument Amplifier
Input Using a Port of the MCU
0
UNIT 3
–1
–2
–50
–25
0
25
50
75
100
125
T
(°C)
Figure 6. Input Offset Voltage versus Temperature
To realize such a system, the designer must provide a
calibration procedure which is very time consuming. Some
extra potentiometers must be implemented for setting both the
offset and the Full Scale Output with a complex temperature
compensation network circuit.
The new proposed solution will reduce or eliminate any
calibration procedure.
Motorola Sensor Device Data
Figure 8 shows the analog switches on the front of the
instrument amplifier and the total symmetry of the chain. The
residual resistance RDS(on) of the switches does not introduce
errors due to the high input impedance of the instrument
amplifier.
With the aid of two analog switches, the MCU successively
converts the output signals V1, V2.
Four conversions are necessary to compute the final result.
First, two conversions of V1 and V2 are executed and stored
in the registers R1, R2. Then, the analog switches are
commuted in the opposite position and the two last
conversions of V2x and V1x are executed and stored in the
registers R2x and R1x. Then, the MCU computes the following
equation:
RESULT = (R1 – R2) + (R2x – R1x)
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AN1097
The result is twice a differential conversion. As
demonstrated below, all errors from the instrument amplifier
are cancelled. Other averaging techniques may be used to
ÉÉÉÉ
ÉÉÉÉ
ÉÉÉÉ
ÉÉÉÉ
ÉÉÉÉ
ÉÉÉÉ
ÉÉÉÉ
ÉÉÉÉ
ÉÉÉÉ
MC74HC4053
MPX2100AP
3
2
PRESSURE
SENSOR
SYSTEM
Freescale Semiconductor, Inc...
4
1
improve the result, but the appropriated algorithm is always
determined by the maximum bandwidth of the input signal
and the required accuracy of the system.
ÉÉÉÉÉ
ÉÉÉÉÉ
ÉÉÉÉÉ
ÉÉÉÉÉ
ÉÉÉÉÉ
ÉÉÉÉÉ
ÉÉÉÉÉ
ÉÉÉÉÉ
ÉÉÉÉÉ
+5V
MC33078
+
VRH
CH1
–
I/O
Rf
Rg
MC68HC05B6
P
Rf
+
–
VDD
V1
CH2
V2
VRL
VSS
0V
Figure 9. Two Channel Input and One Output Port Are Used by the MCU
SYSTEM CALCULATION
Sensor out 2
Vs2 = a (P) + of2
Sensor out 4
Vs4 = b (P) + of4
Amplifier out 1
V1 = Avd (Vs2 + OF1)
Amplifier out 2
V2 = Avd (Vs4 + OF2)
Inverting of the amplifier input
V1x = Avd (Vs4 + OF1)
V2x = Avd (Vs2 + OF2)
Delta = V1–V2
1st differential result
= Avd * (Vs2 of OF1) – Avd * (Vs4 + OF2)
Deltax = V2x–V1x
2nd differential result
= Avd * (Vs2 + OF2) – Vdc * (Vs4 + OF1)
Adding of the two differential results
VoutV = Delta + Deltax
= Avd*Vs2 + Avd*OF2 + Avd*OF2 – Avd*OF1
+ Avd*OF1 – Avd*OF2 + Avd*OF2 – Avd*OF1
= 2 * Avd * (Vs2 –Vs4)
= 2 * Avd * [(a (P) + of2) – (b (P) + of4)]
= 2 * Avd * [V(P) + Voffset]
neglected. That means the system does not require any
calibration procedure.
The equation of the system transfer is then:
count = 2 * Avd * V(P) * 51/V where:
Avd is the differential–mode gain of the instrument amplifier
which is calculated using the equation (1). Then with Rf = 510
kΩ and Rg = 9.1 kΩ Avd = 113.
The maximum counts available in the MCU register at the
Full Scale Pressure is:
count (Full Scale) = 2 * 113 * 0.02 V * 51/V = 230
knowing that the MPX2100AP pressure sensor provides
20 mV at 5.0 excitation voltage and 100 kPa full scale
pressure.
The system resolution is 100 kPa/230 that give 0.43 kPa per
count.
+5V
VDD
There is a full cancellation of the amplifier offset OF1 and
OF2. The addition of the two differential results V1–V2 and
V2x–V1X produce a virtual output voltage VoutV which
becomes the applied input voltage to the A/D converter. The
result of the conversion is expressed in the number of counts
or bits by the ratiometric formula shown below:
count = VoutV *
VRH
I/O
CH1
MC68HC05B6
P
CH2
255
VRH–VRL
255 is the maximum number of counts provided by the A/D
converter and VRH–VRL is the reference voltage of the
ratiometric A/D converter which is commonly tied to the 5.0 V
supply voltage of the MCU.
When the tolerance of the full scale pressure has to be in the
range of ± 2.5%, the offset of the pressure sensor may be
3–206
FINE
CAL.
VRL
VSS
0V
Figure 10. Full Scale Output Calibration Using the
Reference Voltage VRH–VRL
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When the tolerance of the system has to be in the range of
±1%, the designer should provide only one calibration
ÉÉÉÉ
ÉÉÉÉ
ÉÉÉÉ
ÉÉÉÉ
ÉÉÉÉ
ÉÉÉÉ
ÉÉÉÉ
ÉÉÉÉ
MC74HC4053
MPX2100AP
3
2
Freescale Semiconductor, Inc...
4
1
PRESSURE
SENSOR
SYSTEM
AN1097
procedure which sets the Full Scale Output (counts) at 25°C
100 kPa or under the local atmospheric pressure conditions.
ÉÉÉÉÉ
ÉÉÉÉÉ
ÉÉÉÉÉ
ÉÉÉÉÉ
ÉÉÉÉÉ
ÉÉÉÉÉ
ÉÉÉÉÉ
ÉÉÉÉÉ
ÉÉÉÉÉ
ÉÉÉÉÉ
+5V
MC33078
+
ÉÉÉ
ÉÉÉ
ÉÉÉ
ÉÉÉ
–
Rf
Rg
Rf
–
+
VRH
1/3
MC74HC4053
V1
VDD
P1
I/O
MC68HC05B6
CH1
P2
V2
VRL
VSS
0V
Figure 11. One Channel Input and Two Output Ports are used by the MCU
Due to the high impedance input of the A/D converter of the
MC68HC05B6 MCU, another configuration may be
implemented which uses only one channel input as shown in
Figure 11. It is interesting to notice that practically any dual op
amp may be used to do the job but a global consideration must
be made to optimize the total cost of the system according the
the requested specification.
When the Full Scale Pressure has to be sent with accuracy,
the calibration procedure may be executed in different ways.
For instance, the module may be calibrated directly using
Up/Down push buttons.
The gain of the chain is set by changing the VRH voltage of
the ratiometric A/D converter with the R/2R ladder network
circuit which is directly drived by the ports of the MCU. (See
Figure 12.)
Using a communication bus, the calibration procedure may
be executed from a host computer. In both cases, the setting
value is stored in the EEROM of the MCU.
The gain may be also set using a potentiometer in place of
the resistor Rf. But, this component is expensive, taking into
account that it must be stable over the temperature range at
long term.
+5V
2R
RO
VDD
VRH
I/O
2R
P3
R
R/2R
LADDER R
NETWORK
R
2R
P2
BUS
MC68HC05B6
2R
P1
+5V
2R
P0
CH1
CH2
VRL
VSS
UP
DOWN
0V
Figure 12.
Table 1. Pressure Conversion Table
Unity
Pa
mbar
Torr
atm
at=kp/cm2
mWS
psi
1 N/m2 = 1 Pascal
1
0.01
7.5 10–3
—
—
—
—
100
1
0.75
—
—
0.0102
0.014
1 Torr = 1 mmHg
133.32
1.333
.1
—
—
—
0.019
1 atm (1)
101325
1013.2
760
1
1.033
10.33
14.69
1 at = 1 kp/cm2 (2)
98066.5
981
735.6
0.97
1
10
14.22
1 m of water
9806.65
98.1
73.56
0.097
0.1
1
1.422
1 lb/sqin = 1 psi
6894.8
68.95
51.71
0.068
—
—
1
1 mbar
(1) Normal atmosphere
(2) Technical atmosphere
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MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
AN1100
Analog to Digital Converter Resolution
Extension Using a Motorola Pressure Sensor
PURPOSE
Freescale Semiconductor, Inc...
This paper describes a simple method to gain more than
8–bits of resolution with an 8–bit A/D. The electronic design is
relatively simple and uses standard components.
Refer to Figure 1 and assume a pressure of 124 kPa is to
be measured. With this system, the input signal to the A/D
should read (assuming no offset voltage error):
V m(measured)
PRINCIPLE
Consider a requirement to measure pressure up to
200 kPa. Using a pressure sensor and an amplifier, this
pressure can be converted to an analog voltage output. This
analog voltage can then be converted to a digital value and
used by the microprocessor as shown in Figure 1.
If we assume for this circuit that 200 kPa results in a +4.5 V
output, the sensitivity of our system is:/
+ 4.5 Vń200kPa
+ 0.0225 VńkPa
S + 22.5 mVńkPa
(1)
S
or
+ 5Vń ǒ
+ 0.01961 V
R v + 19.60 mV per bit
S
or
+ 5Vń255Ǔ
2 8–1
(2)
M
(5)
+ (142 count) x ǒ19.60mVń
count)
+ 2783 mV
(6)
The microprocessor will output the stored value M to the
D/A. The corresponding voltage at the analog output of the
D/A, for an 8–bit D/A with same references, will be 2783 mV.
The calculated pressure corresponding to this voltage
would be:
P c (calculated)
+ 5Vń ǒ19.60 mVńbit) ńǒ22.5 mVńkPaǓ
+ 0.871 kPa per bit
+ (2790 mV)ń ǒ19.60 mVńbitǓ
+ 142.35
+ 142 (truncated to integer)
The calculated voltage for this stored value is:
This corresponds to a pressure resolution of:
RP
(4)
where Papp is the pressure applied to the sensor.
Due to the resolution of the A/D, the microprocessor
receives the following conversion:
V c (calculated)
If an 8–bit A/D is used with 0 and 5 Volt low and high
references, respectively, then the resolution would be:
+ 4.5 (Papp) x (S)
+ (124 kPa) x ǒ22.5 mVńkPaǓ
+ 2790 mV,
+ (2783 mV)ń ǒ22.5 mVńkPaǓ
(7)
123.7 kPa
(3)
Thus, the error would be:
E
Assume a resolution of at least 0.1 kPa/bit is needed. This
would require an A/D with at least 12 bits ( 212 = 4096 steps).
One can artificially increase the A/D resolution as described
below.
+ Papp–Pc
+ 124 kPa–123.7 kPa
+ 0.3 kPa
(8)
This is greater than the 0.1 kPa resolution requirement.
+V
G
Vm
A/D
M
MPU
Pc
OUTPUT
CIRCUITRY
Figure 1. Block Diagram
REV 1
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AN1100
+V
Vm
M
G
A/D
Σ
C
D
G
–
Control
OUTPUT
CIRCUITRY
MPU
Vc
M
Freescale Semiconductor, Inc...
D/A
ANALOG CIRCUITRY
Figure 2. Expanded Block Diagram
Figure 2 shows the block diagram of a system that can be
used to reduce the inaccuracies caused by the limited A/D
resolution. The microprocessor would use the stored value M,
as described above, to cause a D/A to output the
corresponding voltage, Vc. Vc is subtracted from the
measured voltage, Vm, using a differential amplifier, and the
resulting voltage is amplified. Assuming a gain, G, of 10 for the
amplifier, the output would be:
D
+ (Vm–Vc) G
+ (2790 mV–2783 mV)
+ 70 mV
(9)
Expanded Voltage
+ 70mVńǒ19.60 mVńcountǓ
+ 3.6
+ 3 full counts
+ Vc ) ǒ ǒC R)ń G)
+ 2783 ) ǒǒ 3 19.60)ń10)
+ 2789 mV,
(11)
NOTE: R is resolution of 8-bit d/A
Corresponding Pressure
10
The microprocessor will receive the following count from the
A/D:
C
The microprocessor then computes the actual pressure
with the following equations:
Thus the error is:
Pressure Error
(10)
+ 2789 mVń
+ 22.5 mVńkPa
+ 123.9 kPa
+ Actual – Measured
+ 124 kPa – 123.9 kPa
+ 0.1 kPa
(12)
(13)
Figures 3 and 4 together provide a more detailed
description of the analog portion of this system.
+V
R4
R3
+V
R2
R5
+
R1
R8
A1
+
–
A2
R6
R7
Note: R7 = R2, R1 = R6
Vm (to Second Stage)
–
R9
R10
Figure 3. First Stage – Differential Amplifier, Offset Adjust and Gain Adjust
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AN1100
Vm
R11
Vm
(from
first
stage)
+
R15
A3
R12
+
–
R14
R16
R17
R13
Note: R14 = R12, R11 = R13
D
A4
–
Freescale Semiconductor, Inc...
from D/A
Vc
Figure 4. Second Stage — Difference Amplifier and Gain
FIRST STAGE (Figure 3)
The first stage consists of the Motorola pressure sensor; in
this case the MPX2200 is used. This sensor typically gives a
full scale span output of 40 mV at 200 kPa. The sensor output
(VS) is connected to the inputs of amplifier A1 (1/4 of the
MC33079, a Quad Operational Amplifier). The gain, G1, of this
amplifier is R7/R6. The sensor has a typical zero pressure
offset voltage of 1 mV. Figure 3 shows offset compensation
circuitry if it is needed. A1 output is fed to the non–inverting
input of A2 amplifier (1/4 of a MC33079) whose gain, G2, is
1+R10/R9. G2 should be set to yield 4.5 volts out with full–rated
pressure.
The theoretical resolution is limited only by the accuracy of
the programmable power supply. The Motorola
microprocessor used has an integrated A/D. The accuracy of
this A/D is directly related to the reference voltage source
stability, which can be self–calibrated by the microprocessor.
Vexpanded is the system output that is the sum of the voltage
due to the count and the voltage due to the difference between
the count voltage and the measured voltage. This is given by
the following relation:
+ Vc ) DńG3
PV expanded + V expandedńS.
V expanded
therefore,
THE SECOND STAGE (Figure 4)
The output from A2 (Vm = G1 x G2 x Vs) is connected to the
non–inverting input of amplifier A3 (1/4 of a MC33079) and to
the A/D where its corresponding (digital) value is stored by the
microprocessor. The output of A3 is the amplified difference
between Vm, and the digitized/calculated voltage Vc.
Amplifier A4 (1/4 of a MC33079) provides additional gain for
an amplified difference output for the desired resolution. This
difference output, D, is given by:
+ ǒVm – VcǓ G3
G3 + ǒR14ń R13Ǔ 1 ) R17
R16
D
ǒ
Ǔ
Pexpanded is the value of pressure (in units of kPa) that
results from this improved–resolution system. This value can
be output to a display or used for further processing in a control
system.
CONCLUSION
This circuit provides an easy way to have high resolution
using inexpensive microprocessors and converters.
where G3 is the gain associated with amplifiers A3 and A4.
3–210
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MOTOROLA
SEMICONDUCTOR APPLICATION NOTE
A Simple 4-20 mA Pressure Transducer
Evaluation Board
AN1303
Prepared by: Denise Williams
Discrete Applications Engineering
Freescale Semiconductor, Inc...
INTRODUCTION
The two wire 4 – 20 mA current loop is one of the most widely
utilized transmission signals for use with transducers in
industrial applications. A two wire transmitter allows signal
and power to be supplied on a single wire–pair. Because the
information is transmitted as current, the signal is relatively
immune to voltage drops from long runs and noise from
motors, relays, switches and industrial equipment. The use of
additional power sources is not desirable because the
usefulness of this system is greatest when a signal has to be
transmitted over a long distance with the sensor at a remote
location. Therefore, the 4 mA minimum current in the loop is
the maximum usable current to power the entire control
circuitry.
Figure 1 is a block diagram of a typical 4 – 20 mA current
loop system which illustrates a simple two chip solution to
converting pressure to a 4 – 20 mA signal. This system is
designed to be powered with a 24 Vdc supply. Pressure is
converted to a differential voltage by the Motorola MPX5100
pressure sensor. The voltage signal proportional to the
monitored pressure is then converted to the 4 – 20 mA current
signal with the Burr–Brown XTR101 Precision Two–Wire
Transmitter. The current signal can be monitored by a meter
in series with the supply or by measuring the voltage drop
across RL. A key advantage to this system is that circuit
performance is not affected by a long transmission line.
SENSOR
PRESSURE
PORT
PRESSURE
SOURCE
PRESSURE
SENSOR
TRANSMITTER
CIRCUITRY
ÄÄÄÄ
ÄÄ
ÄÄ
ÄÄÄÄ
ÄÄ
ÄÄ
TRANSMISSION
LINE
4 – 20 mA PRESSURE TRANSDUCER
24 VDC
RL
CURRENT
METER
Figure 1. System Block Diagram
REV 4
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AN1303
INPUT TERMINALS
A schematic of the 4 – 20 mA Pressure Transducer topology
is shown in Figure 2. Connections to this topology are made
at the terminals labeled (+) and (–). Because this system
utilizes a current signal, the power supply, the load and any
current meter must be put in series with the (+) to (–) terminals
as indicated in the block diagram. The load for this type of
system is typically a few hundred ohms. As described above,
a typical use of a 4 – 20 mA current transmission signal is the
transfer of information over long distances. Therefore, a long
transmission line can be connected between the (+) and (–)
terminals on the evaluation board and the power supply/load.
2 mA
3
2
10 11
Freescale Semiconductor, Inc...
XDCR1
MPX7100
D2
1N4565A
6.4V @ 0.5mA
R3
39
4
1
R5
50
4
5
U1
XTR101
6
3
R6
100K
R2
1K
12
1 2 14 7 13
+ 4 – 20 mA OUTPUT
R1
750
1/2 W
8
D1
1N4002
Q1
MPSA06
C1
0.01µF
9
– RETURN
R4
1M
4 – 20 mA PRESSURE TRANSDUCER
Figure 2. Schematic Diagram
PRESSURE INPUT
The device supplied on this topology is an MPX5100DP,
which provides two ports. P1, the positive pressure port, is on
top of the sensor and P2, the vacuum port, is on the bottom of
the sensor. The system can be supplied up to 15 PSI of
positive pressure to P1 or up to 15 PSI of vacuum to P2 or a
differential pressure up to 15 PSI between P1 and P2. Any of
these pressure applications will create the same results at the
sensor output.
CIRCUIT DESCRIPTION
The XTR101 current transmitter provides two one–milliamp
current sources for sensor excitation when its bias voltage is
between 12 V and 40 V. The MPX5100 series sensors are
constant voltage devices, so a zener, D2, is placed in parallel
with the sensor input terminals. Because the MPX5100 series
parts have a high impedance the zener and sensor
combination can be biased with just the two milliamps
available from the XTR101.
The offset adjustment is composed of R4 and R6. They are
used to remove the offset voltage at the differential inputs to
the XTR101. R6 is set so a zero input pressure will result in
the desired output of 4 mA.
R3 and R5 are used to provide the full scale current span of
16 mA. R5 is set such that a 15 PSI input pressure results in
the desired output of 20 mA. Thus the current signal will span
3–212
16 mA from the zero pressure output of 4 mA to the full scale
output of 20 mA. To calculate the resistor required to set the
full scale output span, the input voltage span must be defined.
The full scale output span of the sensor is 24.8 mV and is ∆VIN
to the XTR101. Burr–Brown specifies the following equation
for Rspan. The 40 and 16 mΩ values are parameters of the
XTR101.
R span
+ 40ń ƪ ǒ16 mA ń DVin) * 0.016 mhos]
+ 64 W
The XTR101 requires that the differential input voltage at
pins 3 and 4, V2 – V1 be less than 1V and that V2 (pin 4)
always be greater than V1 (pin 3). Furthermore, this
differential voltage is required to have a common mode of 4–6
volts above the reference (pin 7). The sensor produces the
differential output with a common mode of approximately 3.1
volts above its reference pin 1. Because the current of both 1
mA sources will go through R2, a total common mode voltage
of about 5.1 volts (1 kΩ x 2 mA + 3.1 volts = 5.1 volts) is
provided.
CONCLUSION
This circuit is an example of how the MPX5000 series
sensors can be utilized in an industrial application. It provides
a simple design alternative where remote pressure sensing is
required.
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AN1303
Table 1. Parts List for 4 – 20 mA Pressure Transducer Evaluation Board
Freescale Semiconductor, Inc...
Designator
Quantity
Description
1
1
4
4
2
2
PC Board (see Figure 3)
Input/Output Terminals
1/2″ standoffs, Nylon threaded
1/2″ screws, Nylon
5/8″ screws, Nylon
4–40 nuts, Nylon
C1
1
Capacitor
0.01 µF
D1
D2
1
1
Diodes
100 V Diode
6.4 V Zener
Q1
1
Transistor
NPN Bipolar
R1
R2
R3
R4
1
1
1
1
Resistors, Fixed
750 Ω
1 kΩ
39 Ω
1 MΩ
R5
R6
1
1
U1
XDCR1
Rating
Manufacturer
Motorola
PHX CONT
Part Number
DEVB126
#1727010
50 V
1A
1N4002
1N4565A
Motorola
MPSA06
Resistors, Variable
50 Ω, one turn
100 KΩ, one turn
Bourns
Bourns
#3386P–1–500
#3386P–1–104
1
Integrated Circuit
Two wire current transmitter
Burr–Brown
XTR101
1
Sensor
High Impedance
Motorola
MPX5100DP
1/2 W
15 PSI
NOTE: All resistors are 1/4 W with a tolerance of 5% unless otherwise noted. All capacitors are 100 volt, ceramic capacitors with a tolerance
of 10% unless otherwise noted.
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MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
Integrated Sensor Simplifies Bar Graph
Pressure Gauge
AN1304
Prepared by: Warren Schultz
Discrete Applications Engineering
Freescale Semiconductor, Inc...
INTRODUCTION
Integrated semiconductor pressure sensors such as the
MPX5100 greatly simplify electronic measurement of
pressure. These devices translate pressure into a 0.5 to 4.5
volt output range that is designed to be directly compatible
with microcomputer A/D inputs. The 0.5 to 4.5 volt range also
facilitates interface with ICs such as the LM3914, making Bar
Graph Pressure Gauges relatively simple. A description of a
Bar Graph Pressure Sensor Evaluation Board and its design
considerations are presented here.
Figure 1. DEVB129 MPX5100 Bar Graph Pressure Gauge
(Board No Longer Available)
REV 1
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EVALUATION BOARD DESCRIPTION
Freescale Semiconductor, Inc...
A summary of the information required to use evaluation
board number DEVB129 is presented as follows. A discussion
of the design appears under the heading Design
Considerations.
FUNCTION
The evaluation board shown in Figure 1 is designed to
provide a 100 kPa full scale pressure measurement. It has two
input ports. P1, the pressure port is on the top side of the
MPX5100 sensor, and P2, a vacuum port, is on the bottom
side. These ports can be supplied up to 100 kPa (15 psi)* of
pressure on P1 or up to 100 kPa of vacuum on P2, or a
differential pressure up to 100 kPa between P1 and P2. Any
of these sources will produce the same output.
The primary output is a 10 segment LED bar graph, which
is labeled in increments of 10 kPa. If full scale pressure is
adjusted for a value other than 100 kPa the bar graph may be
read as a percent of full scale. An analog output is also
provided. It nominally supplies 0.5 volts at zero pressure and
4.5 volts at 100 kPa. Zero and full scale adjustments are made
with potentiometers so labeled at the bottom of the board.
Both adjustments are independent of each other.
ELECTRICAL CHARACTERISTICS
The following electrical characteristics are included to
describe evaluation board operation. They are not
specifications in the usual sense and are intended only as a
guide to operation.
Characteristic
Symbol
Min
Typ
Max
Units
Power Supply Voltage
B+
6.8
—
13.2
Volts
PFS
—
—
100
kPa
PMAX
—
—
700
kPa
VFS
—
4.5
—
Volts
VOFF
—
0.5
—
Volts
Analog Sensitivity
SAOUT
—
40
—
mV/kPa
Quiescent Current
ICC
—
20
—
mA
Full Scale Current
IFS
—
140
—
mA
Full Scale Pressure
Overpressure
Analog Full Scale
Analog Zero Pressure
Offset
PIN–BY–PIN DESCRIPTION
B+:
Input power is supplied at the B+ terminal. Minimum input
voltage is 6.8 volts and maximum is 13.2 volts. The upper limit
is based upon power dissipation in the LM3914 assuming all
10 LED’s are lit and ambient temperature is 25°C. The board
will survive input transients up to 25 volts provided that power
dissipation in the LM3914 does not exceed 1.3 watts.
OUT:
An analog output is supplied at the OUT terminal. The signal
it provides is nominally 0.5 volts at zero pressure and 4.5 volts
at 100 kPa. This output is capable of sourcing 100 µA at full
scale output.
GND:
There are two ground connections. The ground terminal on
the left side of the board is intended for use as the power
supply return. On the right side of the board, one of the test
point terminals is also connected to ground. It provides a
convenient place to connect instrumentation grounds.
TP1:
Test point 1 is connected to the zero pressure reference
voltage and can be used for zero pressure calibration. To
calibrate for zero pressure, this voltage is adjusted with R6 to
match the zero pressure voltage that is measured at the
analog output (OUT) terminal.
TP2:
Test point 2 performs a similar function at full scale. It is
connected to the LM3914’s reference voltage which sets the
trip point for the uppermost LED segment. This voltage is
adjusted via R5 to set full scale pressure.
P1, P2:
Pressure and Vacuum ports P1 & P2 protrude from the
MPX5100 sensor on the right side of the board. Pressure port
P1 is on the top and vacuum port P2 is on the bottom. Neither
is labeled. Either one or a differential pressure applied to both
can be used to obtain full scale readings up to 100 kPa (15 psi).
Maximum safe pressure is 700 kPa.
CONTENT
Board contents are described in the following parts list,
schematic, and silk screen plot. A pin by pin circuit description
follows in the next section.
* 100 kPa = 14.7 psi, 15 psi is used throughout the text for convenience
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AN1304
DESIGN CONSIDERATIONS
Freescale Semiconductor, Inc...
In this type of an application the design challenge is how to
interface a sensor with the bar graph output. MPX5100
Sensors and LM3914 Bar Graph Display drivers fit together so
cleanly that having selected these two devices the rest of the
design is quite straight forward.
A block diagram that appears in Figure 4 shows the
LM3914’s internal architecture. Since the lower resistor in the
input comparator chain is pinned out at RLO, it is a simple
matter to tie this pin to a voltage that is approximately equal
to the MPX5100’s zero pressure output voltage. In Figure 2,
this is accomplished by dividing down the 5 volt regulator’s
output voltage through R1, R4, and adjustment pot R6. The
voltage generated at the wiper of R6 is then fed into RLO which
matches the sensor’s zero pressure voltage and zeros the bar
graph.
The full scale measurement is set by adjusting the upper
comparator’s reference voltage to match the sensor’s output
at full pressure. An internal regulator on the LM3914 sets this
voltage with the aid of resistors R2, R3, and adjustment pot R5
that are shown in Figure 2.
The MPX5100 requires 5 volt regulated power that
is supplied by an MC78L05. The LED’s are powered
directly from LM3914 outputs, which are set up as current
sources. Output current to each LED is approximately
10 times the reference current that flows from pin 7 through
R2, R5, and R3 to ground. In this design it is nominally
(4.5 V/4.9K)10 = 9.2 mA.
Over a zero to 85°C temperature range accuracy for both
the sensor and driver IC are ±2.5%, totaling ±5%. Given a 10
segment display total accuracy is approximately ±(10 kPa
+5%).
CONCLUSION
Perhaps the most noteworthy aspect to the bar graph
pressure gauge described here is how easy it is to design. The
interface between an MPX5100 sensor, LM3914 display
driver, and bar graph output is direct and straight forward. The
result is a simple circuit that is capable of measuring pressure,
vacuum, or differential pressure; and will also send an analog
signal to other control circuitry.
S1
+12 V
D1
ON/OFF
D2
D3
D4
D5
D6
D7
D8
D9
D10
C2
1 µF
U3
3
I
MC78L05ACP
U1
C1
0.1 µF
O
1
R4
G
2
1.3K
3
1
2
GND
1
2
3
4
5
6
7
8
9
U2
MPX5100
ZERO
CAL.
LED
GND
B+
RLO
SIG
RHI
REF
ADJ
MOD
R2
1.2 k
R6
100
R1
100
LED
LED
LED
LED
LED
LED
LED
LED
LED
18
17
16
15
14
13
12
11
10
LM3914
R5
1k
TP2 (FULL SCALE CALIBRATION)
TP1 (ZERO CALIBRATION)
GND
FULL SCALE CALIBRATION
R3
2.7 k
ANALOG OUT
Figure 2. MPX5100 Pressure Gauge
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AN1304
MPX5100 PRESSURE GAUGE
MOTOROLA
DISCRETE
APPLICATIONS
PRESSURE
kPa
100
90
70
60
LM3914
MV57164
80
50
MPX5100
40
30
Freescale Semiconductor, Inc...
20
C2
10
C1
B+
TP2
R3
U3
OUT
TP1
R2
GND
ON
DEVB129
R6
GND
R5
OFF
ZERO
FULL SCALE
Figure 3. Silk Screen 2X
Table 1. Parts List
Designators
Quant.
Description
Rating
Manufacturer
Part Number
0.1 µF
1 µF
C1
C2
1
1
Ceramic Cap
Ceramic Cap
D1–D10
1
Bar Graph LED
R1
R2
R3
R4
R5
R6
1
1
1
1
1
1
1/4 W Film Resistor
1/4 W Film Resistor
1/4 W Film Resistor
1/4 W Film Resistor
Trimpot
Trimpot
S1
1
On/Off Switch
NKK
12SDP2
U1
U2
U3
1
1
1
Bar Graph IC
Pressure Sensor
Voltage Regulator
National
Motorola
Motorola
LM3914
MPX5100
MC78L05ACP
—
—
—
—
1
3
4
4
Terminal Block
Test Point Terminal
Nylon Spacer
4–40 Nylon Screw
Augat
Components Corp.
25V03
TP1040104
GI
100
1.2K
2.7K
1.3K
1K
100
MV57164
Bourns
Bourns
3/8″
1/4″
Note: All resistors have a tolerance of 5% unless otherwise noted.
Note: All capacitors are 50 volt ceramic capacitors with a tolerance of 10% unless otherwise noted.
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Freescale Semiconductor, Inc.
AN1304
LED
V+
LM3914
RHI
Freescale Semiconductor, Inc...
REF
OUT
6
7 +
THIS LOAD
DETERMINES
LED
BRIGHTNESS
REF
ADJ
V+
–
+
REFERENCE
VOLTAGE
SOURCE
1.25 V
–
8
3
1k
–
+
11
1k
–
+
12
1k
–
+
13
1k
–
+
14
–
+
15
–
+
16
1k
–
+
17
1k
–
+
18
1k
–
+
1
1k
1k
1k
RLO
COMPARATOR
1 of 10 10
V+
FROM
PIN 11
4
MODE
SELECT
AMPLIFIER
9
–
BUFFER
SIG
IN
5
CONTROLS
TYPE OF
DISPLAY, BAR
OR SINGLE
LED
2
V–
20 k
+
Figure 4. LM3914 Block Diagram
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Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
An Evaluation System for Direct Interface
of the MPX5100 Pressure Sensor with
a Microprocessor
AN1305
Prepared by: Bill Lucas
Discrete Applications Engineering
Freescale Semiconductor, Inc...
INTRODUCTION
Interfacing pressure sensors to analog–to–digital
converters or microprocessors with on–chip A/D converters
has been a challenge that most engineers do not enjoy
accepting. Recent design advances in pressure sensing
technology have allowed the engineer to directly interface a
pressure sensor to an A/D converter with no additional active
components. This has been made possible by integrating a
temperature compensated pressure sensor element and
active linear circuitry on the same die. A description of an
evaluation board that shows the ease of interfacing a signal
conditioned pressure sensor to an A/D converter is presented
here.
Figure 1. DEVB–114 MPX5100 Evaluation Module
(Board No Longer Available)
REV 1
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AN1305
offset. The sensor’s zero offset voltage with no pressure
applied to the sensor is empirically computed each time power
is applied to the system and stored in RAM. The sensitivity of
the MPX5100 is repeatable from unit to unit. There is a facility
for a small “rubbering” of the slope constant built into the
program. It is accomplished with jumpers J1 and J2, and is
explained in the Operation section. The board contents are
further described in the schematic, silk screen plot, and parts
list that appear in Figures 2, 3 and Table 1.
PURPOSE
This evaluation system, shown in Figure 1, demonstrates
the ease of operation and interfacing of the Motorola
MPX5100 series pressure sensors with on–chip temperature
compensation, calibration and amplification. The board may
be used to evaluate the sensor’s suitability for a specific
application.
DESCRIPTION
BASIC CIRCUIT
Freescale Semiconductor, Inc...
The DEVB–114 evaluation board is constructed on a small
printed circuit board. It is powered from a single +5 Vdc
regulated power supply. The system will display the pressure
applied to the MPX5100 sensor in pounds per square inch.
The range is 0 PSI through 15 PSI, resolved to 0.1 PSI. No
potentiometers are used in the system to adjust the span and
The evaluation board consists of three basic subsystems:
an MPX5100GP pressure sensor, a four digit liquid crystal
display (only three digits and a decimal are used) and a
programmed microprocessor with the necessary external
circuitry to support the operation of the microprocessor.
LCD
LIQUID CRYSTAL DISPLAY
IEE PART NUMBER LCD5657 OR EQUAL
BP
28 37 36 5
6
7 34 35
8
49
0
31 32 9
10
11 29 30
12
47 48 42 43 44 45 46
2 1 7 6
5 4 3
26 27 13 14
15 24 25
16
22 23 17
37 38 32 33 34 35 36
2 1 7 6
5 4 3
31
0
29 30 24 25 26 27 28
2 1 7
6
5 4 3
PORTC
PORTB
18 19 20 21
1–4, 33
39, 38, 40
+5
PORTA
R5
52
U1
VRH
TD0
8
15 OHM
1%
∼4.85 V
MC68HC705B5FN
50
44
R6
RDI
VSS
VRL
OSC1
16
OSC2
17
PD5
5
PD6 PD7
4
3
4 MHz
Y1
R3
10K
22 pF
C4
R2
10MEG
J1
4.7K
______
RESET
18
PD4 PD3 PD1 VPP6
VDD PD2
PD0
9 10 11 12 13 14 15
RESET
TCAP1
D/A TCAP2
21 22 23
∼.302 V
R7
30.1 OHM
1%
+5
R1
10K
R4
22 pF
C3
___
IRQ
19
7
453 OHM
1%
+5
U2
IN 34064P–
5
J2
+5
+5
J3
GND
+
C1
100 µF
+5
.1
VCC
C2
OUT
XDCR1
MPX5100
GND
Figure 2. DEVB–114 System Schematic
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AN1305
Table 1. DEVB–114 Parts List
Freescale Semiconductor, Inc...
Designators
Quant.
Description
Rating
Manufacturer
Part Number
C1
1
100 µF Electrolytic Capacitor
25 Vdc
Sprague
513D107M025BB4
C2
1
0.1 µF Ceramic Capacitor
50 Vdc
Sprague
1C105Z5U104M050B
C3, C4
2
22 pF Ceramic Capacitor
100 Vdc
Mepco/Centralab
CN15A220K
J1, J2
1
Dual Row Straight .025 Pins
Arranged On .1″ Grid
Molex
10–89–1043
AMPEREX
LTD226R–12
LCD
1
Liquid Crystal Display
R1
1
4.7 k Ohm Resistor
R2
1
10 Meg Ohm Resistor
R3, R4
2
10 k Ohm Resistor
R5
1
15 Ohm 1% 1/4 W Resistor
R6
1
453 Ohm 1% 1/4 W Resistor
R7
1
30.1 Ohm 1% 1/4 W Resistor
XDCR1
1
Pressure Sensor
Motorola
MPX5100GP
U1
1
Microprocessor
Motorola
Motorola
MC68HC705B5FN or
XC68HC705B5FN
U2
1
Under Voltage Detector
Motorola
MC34064P–5
Y1
1
Crystal (Low Profile)
ECS
ECS–40–S–4
No Designator
1
52 Pin PLCC Socket
AMP
821–575–1
No Designator
2
Jumpers For J1 and J2
Molex
15–29–1025
No Designator
1
Bare Printed Circuit Board
4.0 MHz
Note: All resistors are 1/4 W resistors with a tolerance of 5% unless otherwise noted.
Note: All capacitors are 100 volt, ceramic capacitors with a tolerance of 10% unless otherwise noted.
LCD1
U1
J1
J2
R3
R4
R5
R6
R7
R1
C2 C3
C1
GND
J3
U2
C4
Y1
VCC
R2
XDRC OUT
1
GND
TP1
TP2
TP3
+5
XDRC1
DEVB–114
REV. 0
Figure 3. Silk Screen
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
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3–221
Freescale Semiconductor, Inc.
AN1305
Theory of Operation
Referring to the schematic, Figure 2, the MPX5100
pressure sensor is connected to PORT D bit 5 of the
microprocessor. This port is an input to the on–chip 8 bit
analog to digital converter. The pressure sensor provides a
signal output to the microprocessor of approximately 0.5 Vdc
at 0 psi to 4.5 Vdc at 15 psi of applied pressure as shown in
Figure 4. The input range of the A to D converter is set at
approximately 0.3 Vdc to 4.85 Vdc. This compresses the
range of the A to D converter around the output range of the
sensor to maximize the A to D converter resolution; 0 to 255
counts is the range of the A to D converter. VRH and VRL are
the reference voltage inputs to the A to D converter. The
resolution is defined by the following:
Analog–to–digital converter count =
The count at 0 psi = [(.5 – .302)/(4.85 – .302)] • 255 ≈ 11
The count at 15 psi = [(4.5 – .302)/(4.85 – .302)] • 255 ≈ 235
Therefore the resolution = count @ 15 psi – count @ 0 psi or
the resolution is (235 – 11) = 224 counts. This translates to a
system that will resolve to 0.1 psi.
VS = 5.0 Vdc
TA = 25°C
MPX5100
4.5
OUTPUT (Vdc)
Freescale Semiconductor, Inc...
[(Vxdcr – VRL)/(VRH – VRL)] • 255
TYP
MIN
TYP
SPAN
MAX
The microprocessor section of the system requires certain
support hardware to allow it to function. The MC34064P–5
(U2) provides an under voltage sense function which is used
to reset the microprocessor at system power–up. The 4 MHz
crystal (Y1) provides the external portion of the oscillator
function for clocking the microprocessor and provides a stable
base for time based functions. Jumpers J1 and J2 are
examined by the software and are used to “rubber” the slope
constant.
OPERATION
The system must be connected to a 5 Vdc regulated power
supply. Note the polarity marked on the power terminal J3.
Jumpers J1 and J2 must either both be installed or both be
removed for the normal slope constant to be used. The
pressure port on the MPX5100 sensor must be left open to
atmosphere anytime the board is powered–up. As previously
stated, the sensor’s voltage offset with zero pressure applied
is computed at power–up.
You will need to apply power to the system. The LCD will
display CAL for approximately 5 seconds. After that time, the
LCD will then start displaying pressure.
To improve upon the accuracy of the system, you can
change the constant used by the program that constitutes the
span of the sensor. You will need an accurate test gauge to
measure the pressure applied to the sensor. Anytime after the
display has completed the zero calculation (after CAL is no
longer displayed), apply 15.0 PSI to the sensor. Make sure
that jumpers J1 and J2 are either both installed or both
removed. Referring to Table 2, you can increase the displayed
value by installing J1 and removing J2. Conversely, you can
decrease the displayed value by installing J2 and removing
J1.
J1
J2
IN
OUT
OUT
IN
OUT
IN
IN
OUT
0.5
TYP OFFSET
0
0
kPa
PSI
25
50
75
100
3.62
7.25
10.87
14.5
Action
USE NORMAL SPAN CONSTANT
USE NORMAL SPAN CONSTANT
DECREASE SPAN CONSTANT
APPROXIMATELY 1.5%
INCREASE SPAN CONSTANT
APPROXIMATELY 1.5%
Table 2.
Figure 4. MPX5100 Output versus Pressure Input
SOFTWARE
The voltage divider consisting of R5 through R7 is
connected to the +5 volts powering the system. The output of
the pressure sensor is ratiometric to the voltage applied to it.
The pressure sensor and the voltage divider are connected to
a common supply; this yields a system that is ratiometric. By
nature of this ratiometric system, variations in the voltage of
the power supplied to the system will have no effect on the
system accuracy.
The liquid crystal display is directly driven from I/O ports A,
B, and C on the microprocessor. The operation of a liquid
crystal display requires that the data and backplane pins must
be driven by an alternating signal. This function is provided by
a software routine that toggles the data and backplane at
approximately a 30 Hz rate.
3–222
The source code, compiler listing, and S–record output for
the software used in this system are available on the Motorola
Freeware Bulletin Board Service in the MCU directory under
the filename DEVB–114.ARC. To access the bulletin board
you must have a telephone line, a 300, 1200 or 2400 baud
modem and a terminal or personal computer. The modem
must be compatible with the Bell 212A standard. Call
1–512–891–3733 to access the Bulletin Board Service.
The software for the system consists of several modules.
Their functions provide the capability for system calibration as
well as displaying the pressure input to the MPX5100
transducer.
Figure 5 is a flowchart for the program that controls the
system.
www.motorola.com/semiconductors
For
More Information On This Product,
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
AN1305
START
INITIALIZE DISPLAY I/O PORTS
INITIALIZE TIMER REGISTERS
ALLOW INTERRUPTS
PERFORM AUTO ZERO
SLOPE = 64
TIMER
INTERRUPT
YES
J1 OUT?
SERVICE TIMER REGISTERS
SETUP COUNTER FOR NEXT INTERRUPT
SERVICE LIQUID CRYSTAL DISPLAY
RETURN FROM INTERRUPT
SLOPE = 63
NO
J2 OUT?
YES
SLOPE = 65
Freescale Semiconductor, Inc...
NO
ACCUMULATE 100 A/D CONVERSIONS
COMPUTE INPUT PRESSURE
CONVERT TO DECIMAL
PLACE IN RESULT OUTPUT BUFFER
Figure 5. DEVB–114 Software Flowchart
The compiler used in this project was provided by BYTE
CRAFT LTD. (519) 888–6911. A compiler listing of the
program is included at the end of this document. The following
is a brief explanation of the routines:
delay() Used to provide approximately a 20 ms loop.
read_a2d() Performs one hundred reads on the analog to
digital converter on multiplexer channel 5 and returns the
accumulation.
fixcompare() Services the internal timer for 30 ms timer
compare interrupts.
TIMERCMP() Alternates the data and backplane for the
liquid crystal display.
initio() Sets up the microcomputer’s I/O ports, timer, allows
processor interrupts, and calls adzero().
adzero() This routine is necessary at power–up time
because it delays the power supply and allows the
Motorola Sensor Device Data
transducer to stabilize. It then calls ‘read_atod()’ and saves
the returned value as the sensors output voltage with zero
pressure applied.
cvt_bin_dec(unsigned long arg) This routine converts the
unsigned binary argument passed in ‘arg’ to a five digit
decimal number in an array called ‘digit’. It then uses the
decimal results for each digit as an index into a table that
converts the decimal number into a segment pattern for
the display. It is then output to the display.
display_psi() This routine is called from ‘main()’. The analog to digital converter routine is called, the pressure is
calculated, and the pressure applied to the sensor is displayed. The loop then repeats.
main() This is the main routine called from reset. It calls
‘initio()’ to set up the system’s I/O. ‘display_psi()’ is called
to compute and display the pressure applied to the sensor.
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Information On This Product,
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3–223
AN1305
Freescale Semiconductor, Inc.
SOFTWARE SOURCE/ASSEMBLY PROGRAM CODE
#pragma option v ;
/*
rev 1.1 code rewritten to use the MC68HC705B5 instead of the
MC68HC805B6. WLL 6/17/91
THE FOLLOWING ’C’ SOURCE CODE IS WRITTEN FOR THE DEVB–114 DEMONSTRATION
BOARD. IT WAS COMPILED WITH A COMPILER COURTESY OF:
BYTE CRAFT LTD.
421 KING ST.
WATERLOO, ONTARIO
CANADA N2J 4E4
(519)888–6911
Freescale Semiconductor, Inc...
SOME SOURCE CODE CHANGES MAY BE NECESSARY FOR COMPILATION WITH OTHER
COMPILERS.
BILL LUCAS 8/5/90
MOTOROLA, SPS
*/
0800 1700
0050 0096
#pragma memory ROMPROG [5888]
#pragma memory RAMPAGE0 [150]
1FFE
1FFC
1FFA
1FF8
1FF6
1FF4
1FF2
/*
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
@ 0x0800 ;
@ 0x0050 ;
Vector assignments
*/
vector __RESET
@ 0x1ffe
vector __SWI
@ 0x1ffc
vector IRQ
@ 0x1ffa
vector TIMERCAP @ 0x1ff8
vector TIMERCMP @ 0x1ff6
vector TIMEROV
@ 0x1ff4
vector SCI
@ 0x1ff2
;
;
;
;
;
;
;
#pragma has STOP ;
#pragma has WAIT ;
#pragma has MUL ;
0000
0001
0002
0003
0004
0005
0006
0007
0008
0009
000A
000B
000C
000D
000E
000F
0010
3–224
/*
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
Register assignments for the 68HC705B5 microcontroller
*/
portrw porta
@ 0x00; /*
portrw portb
@ 0x01; /*
portrw portc
@ 0x02; /*
portrw portd
@ 0x03; /* in ,– ,SS ,SCK ,MOSI,MISO,TxD,RxD
portrw ddra
@ 0x04; /* Data direction, Port A
portrw ddrb
@ 0x05; /* Data direction, Port B
portrw ddrc
@ 0x06; /* Data direction, Port C (all output)
portrw eeclk
@ 0x07; /* eeprom/eclk cntl */
portrw addata @ 0x08; /* a/d data register */
portrw adstat @ 0x09; /* a/d stat/control */
portrw plma
@ 0x0a; /* pulse length modulation a */
portrw plmb
@ 0x0b; /* pulse length modulation b */
portrw misc
@ 0x0c; /* miscellaneous register */
portrw scibaud @ 0x0d; /* sci baud rate register */
portrw scicntl1 @ 0x0e; /* sci control 1 */
portrw scicntl2 @ 0x0f; /* sci control 2 */
portrw scistat @ 0x10; /* sci status reg */
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For
More Information On This Product,
Go to: www.freescale.com
*/
*/
*/
*/
*/
*/
*/
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
0011
0012
0013
0014
0015
0016
0017
0018
0019
001A
001B
001C
001D
001E
001F
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
portrw
portrw
portrw
portrw
portrw
portrw
portrw
portrw
portrw
portrw
portrw
portrw
portrw
portrw
portrw
scidata
tcr
tsr
icaphi1
icaplo1
ocmphi1
ocmplo1
tcnthi
tcntlo
acnthi
acntlo
icaphi2
icaplo2
ocmphi2
ocmplo2
@
@
@
@
@
@
@
@
@
@
@
@
@
@
@
0x11;
0x12;
0x13;
0x14;
0x15;
0x16;
0x17;
0x18;
0x19;
0x1A;
0x1B;
0x1c;
0x1d;
0x1e;
0x1f;
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
AN1305
SCI Data */
ICIE,OCIE,TOIE,0;0,0,IEGE,OLVL
*/
ICF,OCF,TOF,0; 0,0,0,0
*/
Input Capture Reg (Hi–0x14, Lo–0x15) */
Input Capture Reg (Hi–0x14, Lo–0x15) */
Output Compare Reg (Hi–0x16, Lo–0x17)*/
Output Compare Reg (Hi–0x16, Lo–0x17)*/
Timer Count Reg (Hi–0x18, Lo–0x19)
*/
Timer Count Reg (Hi–0x18, Lo–0x19)
*/
Alternate Count Reg (Hi–$1A, Lo–$1B) */
Alternate Count Reg (Hi–$1A, Lo–$1B) */
Input Capture Reg (Hi–0x1c, Lo–0x1d) */
Input Capture Reg (Hi–0x1c, Lo–0x1d) */
Output Compare Reg (Hi–0x1e, Lo–0x1f)*/
Output Compare Reg (Hi–0x1e, Lo–0x1f)*/
/* put constants and variables here...they must be global */
Freescale Semiconductor, Inc...
1EFE 74
/***********************************************************************/
#pragma mor @ 0x1EFE = 0x74; /* this disables the watchdog counter and does not
add pull–down resistors on ports B and C */
0800 FC 30 DA 7A 36 6E E6 38 FE
0809 3E
const char lcdtab[]={0xfc,0x30,0xda,0x7a,0x36,0x6e,0xe6,0x38,0xfe,0x3e };
080A 27 10 03 E8 00 64 00 0A
/* lcd pattern table 0
1
2
3
4
5
const long dectable[] = { 10000, 1000, 100, 10 };
6
7
8
9
*/
0050 0005
unsigned int digit[5]; /* buffer to hold results from cvt_bin_dec functio */
0000
registera ac;
/* processor’s A register */
0055
long atodtemp;
/* temp to accumulate 100 a/d readings for smoothing */
0059
long slope;
/* multiplier for adc to engineering units conversion */
005B
int adcnt;
/* a/d converter loop counter */
005C
long xdcr_offset;
/* initial xdcr offset */
005E 0060
unsigned long i,j; /* counter for loops */
0062
int k;
/* misc variable */
struct bothbytes
{ int hi;
int lo;
};
union isboth
{ long l;
struct bothbytes b;
};
0063 0002
Motorola Sensor Device Data
union isboth q;
/* used for timer set–up */
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Information On This Product,
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3–225
Freescale Semiconductor, Inc.
AN1305
/**************************************************************************/
/* code starts here */
/**************************************************************************/
/* these interrupts are not used...give them a graceful return if for
some reason one occurs */
1FFC
0812
1FFA
0813
1FF8
0814
1FF4
0815
1FF2
0816
08
80
08
80
08
80
08
80
08
80
12
__SWI(){}
RTI
13
IRQ(){}
RTI
14
TIMERCAP(){}
RTI
15
TIMEROV(){}
RTI
16
SCI(){}
RTI
Freescale Semiconductor, Inc...
/**************************************************************************/
0817
0818
081A
081C
081E
0820
0822
0824
0826
0828
082A
082C
082E
0830
0832
0834
0836
4F
3F
B7
B6
B7
B6
B7
B6
A0
B6
A2
24
3C
26
3C
20
81
57
58
57
5E
58
5F
5F
20
5E
4E
08
5F
02
5E
EE
CLRA
CLR
STA
LDA
STA
LDA
STA
LDA
SUB
LDA
SBC
BCC
INC
BNE
INC
BRA
RTS
void delay(void) /* just hang around for a while */
{
for (i=0; i<20000; ++i);
$57
$58
$57
$5E
$58
$5F
$5F
#$20
$5E
#$4E
$0836
$5F
$0834
$5E
$0824
}
/**************************************************************************/
read_a2d(void)
{
/* read the a/d converter on channel 5 and accumulate the result
in atodtemp */
0837
0839
083B
083C
083E
0840
0842
0844
3F
3F
4F
B7
B6
A8
A1
24
3–226
56
55
5B
5B
80
E4
21
CLR
CLR
CLRA
STA
LDA
EOR
CMP
BCC
$56
$55
atodtemp=0;
/* zero for accumulation */
for ( adcnt = 0 ; adcnt<100; ++adcnt) /* do 100 a/d conversions */
$5B
$5B
#$80
#$E4
$0867
www.motorola.com/semiconductors
For
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
AN1305
{
0846
0848
084A
084D
084F
0851
0853
0855
0857
0859
085B
085D
085F
0861
A6
B7
0F
B6
3F
B7
BB
B7
B6
B9
B7
B7
B6
B7
25
09
09 FD
08
57
58
56
58
57
55
57
55
58
56
LDA
#$25
STA
$09
BRCLR 7,$09,$084A
LDA
$08
CLR
$57
STA
$58
ADD
$56
STA
$58
LDA
$57
ADC
$55
STA
$57
STA
$55
LDA
$58
STA
$56
0863
0865
0867
0869
086B
086D
086F
0871
0873
0875
0878
087B
087D
087F
3C
20
B6
B7
B6
B7
3F
A6
B7
CD
CD
BF
B7
81
5B
D7
56
58
55
57
66
64
67
0A 5E
0A 8F
55
56
INC
BRA
LDA
STA
LDA
STA
CLR
LDA
STA
JSR
JSR
STX
STA
RTS
adstat = 0x25;
/* convert on channel 5 */
while (!(adstat & 0x80)); /* wait for a/d to complete */
atodtemp = addata + atodtemp;
Freescale Semiconductor, Inc...
}
$5B
$083E
$56
$58
$55
$57
$66
#$64
$67
$0A5E
$0A8F
$55
$56
atodtemp = atodtemp/100;
return atodtemp;
}
/**************************************************************************/
0880
0882
0884
0886
0888
088A
088C
088E
0890
0892
0894
0896
0898
089A
B6
B7
B6
B7
AB
B7
B6
A9
B7
B7
B6
B6
B7
81
18
63
19
64
4C
64
63
1D
63
16
13
64
17
LDA
STA
LDA
STA
ADD
STA
LDA
ADC
STA
STA
LDA
LDA
STA
RTS
$18
$63
$19
$64
#$4C
$64
$63
#$1D
$63
$16
$13
$64
$17
1FF6 08 9B
Motorola Sensor Device Data
void fixcompare (void) /* sets–up the timer compare for the next interrup */
{
q.b.hi =tcnthi;
q.b.lo = tcntlo;
q.l +=7500;
/* ((4mhz xtal/2)/4) = counter period = 2us.*7500 = 15ms.*/
ocmphi1 = q.b.hi;
ac=tsr;
ocmplo1 = q.b.lo;
}
/*************************************************************************/
void TIMERCMP (void)
/* timer service module */
{
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For More
Information On This Product,
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3–227
Freescale Semiconductor, Inc.
AN1305
089B
089D
089F
08A1
08A3
33
33
33
AD
80
02
01
00
DD
COM
COM
COM
BSR
RTI
$02
$01
$00
$0880
portc =~ portc;
portb =~ portb;
porta =~ porta;
fixcompare();
/* service the lcd */
}
/************************************************************************/
void adzero(void)
/* called by initio() to save initial xdcr’s zero
pressure offset voltage output */
Freescale Semiconductor, Inc...
{
08A4
08A5
08A7
08A9
08AB
08AD
08AF
08B1
08B3
08B5
08B7
08B9
4F
3F
B7
B6
B7
B6
B7
B6
A0
B6
A2
24
57
58
57
60
58
61
61
14
60
00
0B
CLRA
CLR
STA
LDA
STA
LDA
STA
LDA
SUB
LDA
SBC
BCC
for ( j=0; j<20; ++j)
/* give the sensor time to ”warm–up” and the
$57
$58
$57
$60
$58
$61
$61
#$14
$60
#$00
$08C6
power supply time to settle down */
{
08BB CD 08 17
JSR
$0817
delay();
}
08BE
08C0
08C2
08C4
08C6
08C9
08CB
08CD
3C
26
3C
20
CD
3F
B7
81
61
02
60
EB
08 37
5C
5D
INC
BNE
INC
BRA
JSR
CLR
STA
RTS
$61
$08C4
$60
$08B1
$0837
$5C
$5D
xdcr_offset =
read_a2d();
}
/**************************************************************************/
08CE
08D0
08D2
08D4
08D6
08D8
08DA
08DC
08DE
08E0
08E2
08E4
08E6
08E8
A6
B7
3F
3F
3F
A6
B7
B7
B7
B6
3F
3F
B6
AD
3–228
20
09
02
01
00
FF
06
05
04
13
1E
16
1F
96
LDA
STA
CLR
CLR
CLR
LDA
STA
STA
STA
LDA
CLR
CLR
LDA
BSR
#$20
$09
$02
$01
$00
#$FF
$06
$05
$04
$13
$1E
$16
$1F
$0880
void initio (void)
/* setup the I/O */
{
adstat = 0x20; /* power–up the A/D */
porta = portb = portc = 0;
ddra = ddrb = ddrc = 0xff;
ac=tsr; /* dummy read */
ocmphi1 = ocmphi2 = 0;
ac = ocmplo2; /* clear out output compare 2 if it happens to be set */
fixcompare(); /* set–up for the first timer interrupt */
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For
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
08EA A6 40
08EC B7 12
08EE 9A
LDA
STA
CLI
#$40
$12
08EF
08F1
08F3
08F5
08F7
08F9
08FB
08FD
LDA
STA
LDA
STA
LDA
STA
BSR
RTS
#$CC
$02
#$BE
$01
#$C4
$00
$08A4
A6
B7
A6
B7
A6
B7
AD
81
CC
02
BE
01
C4
00
A7
AN1305
tcr = 0x40;
CLI; /* let the interrupts begin !
/* write CAL to the display */
portc = 0xcc; /* C */
*/
portb = 0xbe; /* A */
porta = 0xc4; /* L */
adzero();
}
/**************************************************************************/
void cvt_bin_dec(unsigned long arg)
Freescale Semiconductor, Inc...
/* First converts the argument to a five digit decimal value. The msd is in
the lowest address. Then leading zero suppresses the value and writes it to
the display ports.
The argument value range is 0..65535 decimal. */
0069
08FE
0900
006B
006C
0902
0903
0905
0907
0909
{
BF 69
B7 6A
4F
B7
B6
A1
24
6B
6B
05
07
STX
STA
CLRA
STA
LDA
CMP
BCC
$69
$6A
char i;
unsigned long l;
for ( i=0; i < 5; ++i )
$6B
$6B
#$05
$0912
{
090B 97
090C 6F 50
TAX
CLR
090E
0910
0912
0913
0915
0917
0919
3C
20
4F
B7
B6
A1
24
6B
6B
04
70
INC
BRA
CLRA
STA
LDA
CMP
BCC
091B
091C
091D
0920
0922
0924
0927
0929
97
58
D6
B1
26
D6
B1
27
08 0B
6A
07
08 0A
69
5C
TAX
LSLX
LDA
CMP
BNE
LDA
CMP
BEQ
092B BE 6B
092D 58
092E D6 08 0A
LDX
LSLX
LDA
digit[i] = 0x0;
/* put blanks in all digit positions */
$50,X
}
6B
F3
$6B
$0905
for ( i=0; i < 4; ++i )
$6B
$6B
#$04
$098B
{
if ( arg
>= dectable [i] )
$080B,X
$6A
$092B
$080A,X
$69
$0987
{
$6B
l = dectable[i];
$080A,X
Motorola Sensor Device Data
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Information On This Product,
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3–229
Freescale Semiconductor, Inc.
Freescale Semiconductor, Inc...
AN1305
0931
0933
0936
0938
093A
093C
093E
0940
0942
0944
0946
0948
094B
094E
0950
0952
0954
0956
0958
095A
095C
095E
0960
0962
0964
0966
0969
096B
096D
096F
0971
0973
0975
0977
0979
097B
097D
097F
0981
0983
0985
B7
D6
B7
B6
B7
B6
B7
B6
B7
B6
B7
CD
CD
BF
B7
BE
E7
BE
E6
3F
B7
B6
B7
B6
B7
CD
BF
B7
33
30
26
3C
B6
BB
B7
B6
B9
B7
B7
B6
B7
6C
08
6D
6A
58
69
57
6C
66
6D
67
0A
0A
57
58
6B
50
6B
50
57
58
6C
66
6D
67
0A
57
58
57
58
02
57
58
6A
58
57
69
57
69
58
6A
0B
5E
8F
3F
STA
LDA
STA
LDA
STA
LDA
STA
LDA
STA
LDA
STA
JSR
JSR
STX
STA
LDX
STA
LDX
LDA
CLR
STA
LDA
STA
LDA
STA
JSR
STX
STA
COM
NEG
BNE
INC
LDA
ADD
STA
LDA
ADC
STA
STA
LDA
STA
$6C
$080B,X
$6D
$6A
$58
$69
$57
$6C
$66
$6D
$67
$0A5E
$0A8F
$57
$58
$6B
$50,X
$6B
$50,X
$57
$58
$6C
$66
$6D
$67
$0A3F
$57
$58
$57
$58
$0975
$57
$58
$6A
$58
$57
$69
$57
$69
$58
$6A
digit[i] = arg / l;
arg = arg–(digit[i] * l);
}
}
0987
0989
098B
098D
098F
0991
0993
0995
0997
3C
20
B6
B7
B6
B7
BE
B6
E7
0999 9B
3–230
6B
8A
6A
58
69
57
6B
58
50
INC
BRA
LDA
STA
LDA
STA
LDX
LDA
STA
SEI
$6B
$0915
$6A
$58
$69
$57
$6B
$58
$50,X
digit[i] = arg;
/* now zero suppress and send the lcd pattern to the display */
SEI;
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More Information On This Product,
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Freescale Semiconductor, Inc...
Freescale Semiconductor, Inc.
099A
099C
099E
09A0
09A2
09A4
09A7
09A9
09AB
09AD
09AF
09B1
09B3
09B5
09B7
09BA
09BC
09BE
09C1
09C2
09C4
09C5
09C8
3D
26
3F
20
BE
D6
B7
3D
26
3D
26
3F
20
BE
D6
B7
BE
D6
4C
B7
9A
CD
81
50
04
02
07
50
08 00
02
50
08
51
04
01
07
51
08 00
01
52
08 00
00
08 17
TST
BNE
CLR
BRA
LDX
LDA
STA
TST
BNE
TST
BNE
CLR
BRA
LDX
LDA
STA
LDX
LDA
INCA
STA
CLI
JSR
RTS
$50
$09A2
$02
$09A9
$50
$0800,X
$02
$50
$09B5
$51
$09B5
$01
$09BC
$51
$0800,X
$01
$52
$0800,X
if ( digit[0] == 0 )
AN1305
/* leading zero suppression */
portc = 0;
else
portc = ( lcdtab[digit[0]] );
/* 100’s digit */
if ( digit[0] == 0 && digit[1] == 0 )
portb=0;
else
portb = ( lcdtab[digit[1]] );
/* 10’s digit */
porta = ( lcdtab[digit[2]]+1 ); /* 1’s digit + decimal point */
$00
CLI;
$0817
delay();
}
/****************************************************************/
09C9
09CB
09CD
09CF
09D1
09D3
3F
A6
B7
B6
A4
B7
59
40
5A
03
C0
62
CLR
LDA
STA
LDA
AND
STA
$59
#$40
$5A
$03
#$C0
$62
09D5
09D7
09D9
09DB
09DD
09DF
A1
26
3F
A6
B7
B6
80
06
59
41
5A
62
CMP
BNE
CLR
LDA
STA
LDA
#$80
$09DF
$59
#$41
$5A
$62
Motorola Sensor Device Data
void display_psi(void)
/* At power–up it is assumed that the pressure port of the sensor
is open to atmosphere. The code in initio() delays for the
sensor and power to stabilize. One hundred A/D conversions are
averaged and divided by 100. The result is called xdcr_offset.
This routine calls the A/D routine which performs one hundred
conversions, divides the result by 100 and returns the value.
If the value returned is less than or equal to the xdcr_offset,
the value of xdcr_offset is substituted. If the value returned
is greater than xdcr_offset, xdcr_offset is subtracted from the
returned value. That result is multiplied by a constant to yield
pressure in PSI * 10 to yield a ”decimal point”.
*/
{
while(1)
{
slope = 64;
k = portd & 0xc0;
if ( k == 0x80 )
/* this lets us ”rubber” the slope to closer fit
the slope of the sensor */
/* J2 removed, J1 installed */
slope = 65;
if ( k == 0x40 ) /* J1 removed, J2 installed */
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3–231
Freescale Semiconductor, Inc.
Freescale Semiconductor, Inc...
AN1305
09E1
09E3
09E5
09E7
09E9
A1
26
3F
A6
B7
40
06
59
3F
5A
CMP
BNE
CLR
LDA
STA
#$40
$09EB
$59
#$3F
$5A
09EB
09EE
09F0
09F2
09F4
09F6
09F8
09FA
09FC
09FE
0A00
0A02
0A04
0A06
0A08
0A0A
0A0C
0A0E
0A10
0A12
0A14
0A16
0A18
0A1A
0A1C
0A1E
0A20
0A22
0A24
0A26
0A28
0A2A
0A2D
0A2F
0A31
0A34
0A36
CD
3F
B7
B0
B7
B6
A8
B7
B6
A8
B2
BA
22
B6
B7
B6
B7
B6
B0
B7
B6
B2
B7
B6
B7
B6
B7
B6
B7
B6
B7
CD
BF
B7
CD
20
81
08 37
55
56
5D
58
5C
80
57
55
80
57
58
08
5C
55
5D
56
56
5D
56
55
5C
55
56
58
55
57
59
66
5A
67
0A 3F
55
56
08 FE
93
JSR
CLR
STA
SUB
STA
LDA
EOR
STA
LDA
EOR
SBC
ORA
BHI
LDA
STA
LDA
STA
LDA
SUB
STA
LDA
SBC
STA
LDA
STA
LDA
STA
LDA
STA
LDA
STA
JSR
STX
STA
JSR
BRA
RTS
$0837
$55
$56
$5D
$58
$5C
#$80
$57
$55
#$80
$57
$58
$0A0E
$5C
$55
$5D
$56
$56
$5D
$56
$55
$5C
$55
$56
$58
$55
$57
$59
$66
$5A
$67
$0A3F
$55
$56
$08FE
$09C9
slope = 63;
/* else both jumpers are removed or installed... don’t change the slope */
atodtemp = read_a2d(); /* atodtemp = raw a/d ( 0..255 ) */
if ( atodtemp <= xdcr_offset )
atodtemp = xdcr_offset;
atodtemp –=
xdcr_offset; /* remove the offset */
atodtemp *= slope; /* convert to psi */
cvt_bin_dec( atodtemp ); /* convert to decimal and display */
}
}
/************************************************************************/
0A37
0A3A
0A3C
0A3E
CD 08 CE
AD 8D
20 FE
81
0A3F BE 58
0A41 B6 67
3–232
JSR
BSR
BRA
RTS
$08CE
$09C9
$0A3C
LDX
LDA
$58
$67
main()
{
initio(); /* set–up the processor’s i/o */
display_psi();
while(1);
/* should never get here */
}
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Motorola Sensor Device Data
Freescale Semiconductor, Inc...
Freescale Semiconductor, Inc.
0A43
0A44
0A46
0A48
0A4A
0A4C
0A4D
0A4F
0A51
0A53
0A55
0A56
0A58
0A5A
0A5B
0A5D
42
B7
BF
BE
B6
42
BB
B7
BE
B6
42
BB
B7
97
B6
81
0A5E
0A60
0A61
0A63
0A65
0A66
0A68
0A6A
0A6C
0A6E
0A70
0A72
0A74
0A76
0A78
0A7A
0A7C
0A7E
0A80
0A82
0A84
0A86
0A88
0A89
0A8A
0A8C
0A8E
0A8F
0A90
0A91
0A93
0A94
1FFE
3F
5F
3F
3F
5C
38
39
39
39
B6
B0
B7
B6
B2
B7
24
B6
BB
B7
B6
B9
B7
99
59
39
24
81
53
9F
BE
53
81
0A
70
71
57
67
71
71
58
66
71
71
70
70
6E
6F
58
57
6E
6F
6E
67
6E
6F
66
6F
0D
67
6E
6E
66
6F
6F
70
D8
70
MUL
STA
STX
LDX
LDA
MUL
ADD
STA
LDX
LDA
MUL
ADD
STA
TAX
LDA
RTS
CLR
CLRX
CLR
CLR
INCX
LSL
ROL
ROL
ROL
LDA
SUB
STA
LDA
SBC
STA
BCC
LDA
ADD
STA
LDA
ADC
STA
SEC
ROLX
ROL
BCC
RTS
COMX
TXA
LDX
COMX
RTS
AN1305
$70
$71
$57
$67
$71
$71
$58
$66
$71
$71
$70
$70
$6E
$6F
$58
$57
$6E
$6F
$6E
$67
$6E
$6F
$66
$6F
$0A89
$67
$6E
$6E
$66
$6F
$6F
$70
$0A66
$70
37
Motorola Sensor Device Data
www.motorola.com/semiconductors
For More
Information On This Product,
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3–233
Freescale Semiconductor, Inc.
AN1305
Freescale Semiconductor, Inc...
SYMBOL TABLE
LABEL
VALUE
LABEL
VALUE
LABEL
VALUE
LABEL
VALUE
IRQ
TIMEROV
__MUL16x16
__STOP
acnthi
adstat
b
ddrb
digit
hi
icaplo1
j
lo
ocmphi2
plmb
portd
scicntl1
slope
tsr
0813
0815
0A3F
0000
001A
0009
0000
0005
0050
0000
0015
0060
0001
001E
000B
0003
000E
0059
0013
SCI
__LDIV
__RDIV
__SWI
acntlo
adzero
bothbytes
ddrc
display_psi
i
icaplo2
k
main
ocmplo1
porta
q
scicntl2
tcnthi
xdcr_offset
0816
0A5E
0A8F
0812
001B
08A4
0002
0006
09C9
005E
001D
0062
0A37
0017
0000
0063
000F
0018
005C
TIMERCAP
__LongIX
__RESET
__WAIT
adcnt
arg
cvt_bin_dec
dectable
eeclk
icaphi1
initio
l
misc
ocmplo2
portb
read_a2d
scidata
tcntlo
0814
0066
1FFE
0000
005B
0069
08FE
080A
0007
0014
08CE
0000
000C
001F
0001
0837
0011
0019
TIMERCMP
__MUL
__STARTUP
__longAC
addata
atodtemp
ddra
delay
fixcompare
icaphi2
isboth
lcdtab
ocmphi1
plma
portc
scibaud
scistat
tcr
089B
0000
0000
0057
0008
0055
0004
0817
0880
001C
0002
0800
0016
000A
0002
000D
0010
0012
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
MEMORY USAGE MAP (’X’ = Used, ’–’ = Unused)
0100
0140
0180
01C0
:
:
:
:
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––X–
0800
0840
0880
08C0
:
:
:
:
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
0900
0940
0980
09C0
:
:
:
:
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
0A00
0A40
0A80
0AC0
:
:
:
:
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
––––––––––––––––
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXX–––––––––––
––––––––––––––––
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
––––––––––––––––
––––––––––––––––
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
––––––––––––––––
––––––––––––––––
1F00
1F40
1F80
1FC0
:
:
:
:
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––XXXXXXXXXXXXXX
All other memory blocks unused.
Errors
:
0
Warnings
:
0
3–234
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Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
Compensated Sensor Bar Graph
Pressure Gauge
AN1309
Prepared by: Warren Schultz
Discrete Applications Engineering
Freescale Semiconductor, Inc...
INTRODUCTION
Compensated semiconductor pressure sensors such as
the MPX2000 family are relatively easy to interface with digital
systems. With these sensors and the circuitry described
herein, pressure is translated into a 0.5 to 4.5 volt output range
that is directly compatible with Microcomputer A/D inputs. The
0.5 to 4.5 volt range also facilitates interface with an LM3914,
making Bar Graph Pressure Gauges relatively simple.
Figure 1. DEVB147 Compensated Pressure Sensor Evaluation Board
(Board No Longer Available)
REV 1
Motorola Sensor Device Data
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3–235
Freescale Semiconductor, Inc.
AN1309
PIN-BY-PIN DESCRIPTION
EVALUATION BOARD DESCRIPTION
Freescale Semiconductor, Inc...
The information required to use evaluation board number
DEVB147 follows, and a discussion of the design appears in
the Design Considerations section.
FUNCTION
The evaluation board shown in Figure 1 is supplied with an
MPX2100DP sensor and provides a 100 kPa full scale
pressure measurement. It has two input ports. P1, the
pressure port, is on the top side of the sensor and P2, a
vacuum port, is on the bottom side. These ports can be
supplied up to 100 kPa (15 psi) of pressure on P1 or up to 100
kPa of vacuum on P2, or a differential pressure up to 100 kPa
between P1 and P2. Any of these sources will produce the
same output.
The primary output is a 10 segment LED bar graph, which
is labeled in increments of 10% of full scale, or 10 kPa with the
MPX2100 sensor. An analog output is also provided. It
nominally supplies 0.5 volts at zero pressure and 4.5 volts at
full scale. Zero and full scale adjustments are made with
potentiometers so labeled at the bottom of the board. Both
adjustments are independent of one another.
ELECTRICAL CHARACTERISTICS
The following electrical characteristics are included as a
guide to operation.
Characteristic
Symbol
Min
Typ
Max
Units
Power Supply Voltage
B+
6.8
—
13.2
dc Volts
PFS
—
—
100
kPa
PMAX
—
—
700
kPa
VFS
—
4.5
—
Volts
VOFF
—
0.5
—
Volts
Analog Sensitivity
SAOUT
—
40
—
mV/kPa
Quiescent Current
ICC
—
40
—
mA
Full Scale Current
IFS
—
160
—
mA
Full Scale Pressure
Overpressure
Analog Full Scale
Analog Zero Pressure
Offset
CONTENT
Board contents are described in the parts list shown in
Table 1. A schematic and silk screen plot are shown in Figures
2 and 6. A pin by pin circuit description follows.
3–236
B+:
Input power is supplied at the B+ terminal. Minimum input
voltage is 6.8 volts and maximum is 13.2 volts. The upper limit
is based upon power dissipation in the LM3914 assuming all
10 LED’s are lit and ambient temperature is 25°C. The board
will survive input transients up to 25 volts provided that
average power dissipation in the LM3914 does not exceed 1.3
watts.
OUT:
An analog output is supplied at the OUT terminal. The signal
it provides is nominally 0.5 volts at zero pressure and 4.5 volts
at full scale. Zero pressure voltage is adjustable and set with
R11. This output is designed to be directly connected to a
microcomputer A/D channel, such as one of the E ports on an
MC68HC11.
GND:
There are two ground connections. The ground terminal on
the left side of the board is intended for use as the power
supply return. On the right side of the board one of the test
point terminals is also connected to ground. It provides a
convenient place to connect instrumentation grounds.
TP1:
Test point 1 is connected to the LM3914’s full scale
reference voltage which sets the trip point for the uppermost
LED segment. This voltage is adjusted via R1 to set full scale
pressure.
TP2:
Test point 2 is connected to the +5.0 volt regulator output.
It can be used to verify that supply voltage is within its 4.75 to
5.25 volt tolerance.
P1, P2:
Pressure and Vacuum ports P1 and P2 protrude from the
sensor on the right side of the board. Pressure port P1 is on
the top and vacuum port P2 is on the bottom. Neither port is
labeled. Maximum safe pressure is 700 kPa.
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
AN1309
S1
B+
ON/OFF
D1
U3A
4
3
+
1
2 –
MC33274
C2
0.1 µF
MC78L05ACP
R7 75
O
G
1
Freescale Semiconductor, Inc...
2
3
2 R8 75
4
1
R5
1k
R13
1k
R10
820
ZERO
CAL.
R11
200
1
2
3
4
5
6
7
8
9
7.5 k
13 U3D
–
14
12
+
MC33274
R3
1.2 k
XDCR1
MPX2100DP
GND
D6 D7
D8
D1-D10
MV57164
BAR
GRAPH
R6
U1 3
I
D9 D10 D2 D3 D4 D5
C1
1 µF
5 U3B
+
7
6 –
MC33274
R4
R1
1k
FULL SCALE CAL.
U2
18
LED
LED 17
GND
LED 16
B+
LED
RLO
LED 15
14
SIG
LED 13
RHI
LED 12
REF
LED
11
ADJ
LED
MOD
LED 10
LM3914N
TP1 (FULL SCALE VOLTAGE)
GND
R2
2.7 k
TP2 +5 VOLTS
R14
470
1k
U3C
10 MC33274
+
9 –
11 8
D11
MV57124A
POWER ON INDICATOR
R12
470
R9
1k
ANALOG OUT
Figure 2. Compensated Pressure Sensor EVB Schematic
B+
C1
0.1 µF
3
U1
I
MC78L05ACP
O
1
G
C2
1 µF
XDCR
MPX2100
3
2
2
U2B
5
4
7
+
6
–
MC33274
R3
4
1
R4 1 k
GND
R5 1 k
13
12
100 k
U2D
–
14
+
MC33274
U2C
MC33274
10
+
9
–
NOTE:
For zero pressure voltage independent
of sensor common mode R6/R7 = R2/R1
R7
R6
1k
1k
8
3 U2A
1
+
2
–
MC33274
R2
R1
1k
1k
OUTPUT
11
VOFFSET
Figure 3. Compensated Sensor Interface
Motorola Sensor Device Data
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3–237
AN1309
Freescale Semiconductor, Inc.
Freescale Semiconductor, Inc...
DESIGN CONSIDERATIONS
In this type of application the design challenge is how to take
a relatively small DC coupled differential signal and produce
a ground referenced output that is suitable for driving
microcomputer A/D inputs. A user friendly interface circuit that
will do this job is shown in Figure 3. It uses one quad op amp
and several resistors to amplify and level shift the sensor’s
output. Most of the amplification is done in U2D which is
configured as a differential amplifier. It is isolated from the
sensor’s positive output by U2B. The purpose of U2B is to
prevent feedback current that flows through R3 and R4 from
flowing into the sensor. At zero pressure the voltage from pin
2 to pin 4 on the sensor is zero volts. For example with the
common mode voltage at 2.5 volts, the zero pressure output
voltage at pin 14 of U2D is then 2.5 volts, since any other
voltage would be coupled back to pin 13 via R3 and create a
nonzero bias across U2D’s differential inputs. This 2.5 volt
zero pressure DC output voltage is then level translated to the
desired zero pressure offset voltage (VOFFSET) by U2C and
U2A. To see how the level translation works, assume 0.5 volts
at (VOFFSET). With 2.5 volts at pin 10, pin 9 is also at 2.5 volts.
This leaves 2.5 – 0.5 = 2.0 volts across R7. Since no current
flows into pin 9, the same current flows through R6, producing
2.0 volts across R6 also. Adding the voltages (0.5 + 2.0 + 2.0)
yields 4.5 volts at pin 8. Similarly 2.5 volts at pin 3 implies 2.5
volts at pin 2, and the drop across R2 is 4.5 V – 2.5 V = 2.0
volts. Again 2.0 volts across R2 implies an equal drop across
R1, and the voltage at pin 1 is 2.5 V – 2.0 V = 0.5 volts. For this
DC output voltage to be independent of the sensor’s common
mode voltage it is necessary to satisfy the condition that
R6/R7 = R2/R1.
Gain is close but not exactly equal to R3/R4(R1/R2+1),
which predicts 200.0 for the values shown in Figure 3. A more
exact calculation can be performed by doing a nodal analysis,
which yields 199.9. Cascading the gains of U2D and U2A
using standard op amp gain equations does not give an exact
result, because the sensor’s negative going differential signal
at pin 4 subtracts from the DC level that is amplified by U2A.
The resulting 0.5 V to 4.5 V output from U2A is directly
compatible with microprocessor A/D inputs. Tying this output
to an LM3914 for a bar graph readout is also very straight
forward. The block diagram that appears in Figure 4 shows the
LM3914’s internal architecture. Since the lower resistor in the
input comparator chain is pinned out at RLO, it is a simple
matter to tie this pin to a voltage that is approximately equal
to the interface circuit’s 0.5 volt zero pressure output voltage.
In Figure 2, this is accomplished by dividing down the 5.0 volt
regulator’s output voltage through R13 and adjustment pot
R11. The voltage generated at R11’s wiper is the offset voltage
identified as VOFFSET in Figure 3. Its source impedance is
chosen to keep the total input impedance to U3C at
approximately 1K. The wiper of R11 is also fed into RLO for
zeroing the bar graph.
The full scale measurement is set by adjusting the upper
comparator’s reference voltage to match the sensor’s output
at full pressure. An internal regulator on the LM3914 sets this
voltage with the aid of resistors R2, R3, and adjustment pot R1
that are shown in Figure 2.
Five volt regulated power is supplied by an MC78L05. The
LED’s are powered directly from LM3914 outputs, which are
set up as current sources. Output current to each LED is
approximately 10 times the reference current that flows from
pin 7 through R3, R1, and R2 to ground. In this design it is
nominally (4.5 V/4.9K)10 = 9.2 mA.
Over a zero to 50°C temperature range combined accuracy
for the sensor, interface and driver IC are +/– 10%. Given a
10 segment display total accuracy for the bar graph readout
is approximately +/– (10 kPa +10%).
APPLICATION
Using the analog output to provide pressure information to
a microcomputer is very straightforward. The output voltage
range, which goes from 0.5 volts at zero pressure to 4.5 volts
at full scale, is designed to make optimum use of
microcomputer A/D inputs. A direct connection from the
evaluation board analog output to an A/D input is all that is
required. Using the MC68HC11 as an example, the output is
connected to any of the E ports, such as port E0 as shown in
Figure 5. To get maximum accuracy from the A/D conversion,
VREFH is tied to 4.85 volts and VREFL is tied to 0.3 volts by
dividing down a 5.0 volt reference with 1% resistors.
CONCLUSION
Perhaps the most noteworthy aspect to the bar graph
pressure gauge described here is the ease with which it can
be designed. The interface between an MPX2000 series
sensor and LM3914 bar graph display driver consists of one
3–238
quad op amp and a few resistors. The result is a simple and
inexpensive circuit that is capable of measuring pressure,
vacuum, or differential pressure with an output that is directly
compatible to a microprocessor.
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
LED
V+
LM3914
–
+
Freescale Semiconductor, Inc...
RHI 6
REF
OUT
7 +
THIS LOAD
DETERMINES
LED
BRIGHTNESS
REF
ADJ
V+
REFERENCE
VOLTAGE
SOURCE
1.25 V
–
8
3
–
+
11
1k
–
+
12
1k
–
+
13
1k
–
+
14
–
+
15
–
+
16
1k
–
+
17
1k
–
+
18
1k
–
+
1
1k
1k
RLO
COMPARATOR
1 of 10 10
1k
1k
V+
FROM
PIN 11
4
MODE
SELECT
AMPLIFIER
9
–
BUFFER
SIG
IN
AN1309
5
CONTROLS
TYPE OF
DISPLAY, BAR
OR SINGLE
LED
2
V–
20 k
+
Figure 4. LM3914 Block Diagram
Motorola Sensor Device Data
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Freescale Semiconductor, Inc.
AN1309
+5 V
15 OHMS
1%
4.85 V
VREFH
453 OHMS
1%
+12 V
VREFL
0.302 V
30.1 OHMS
1%
B+
COMPENSATED SENSOR
BAR GRAPH
PRESSURE GAUGE
ANALOG OUT
Freescale Semiconductor, Inc...
GND
MC68HC11
PRESSURE/
VACUUM
IN
0
1
2
3
4
5
6
7
PORT E
Figure 5. Application Example
COMPENSATED PRESSURE SENSOR EVB
% FULL SCALE
100
U1
C1
90
U3
80
C2
U3
50
MV57164
60
LM3914N
70
SENSOR
40
30
20
U2
10
R12
R2
R3
R10
R9
R4
R5
R8
R6
R7
TP2
R7
R6
R8
R5
R4
R9
R3
R2
R10
OUT
R12
B+
TP1
GND
R14
R13
GND
DEVB147
R14
ON
+
R13
POWER
R11
R1
ZERO
FULL SCALE
OFF
MOTOROLA DISCRETE APPLICATIONS
Figure 6. Silk Screen
3–240
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
AN1309
Table 1. Parts List
Freescale Semiconductor, Inc...
Designator
Qty.
Description
C1
C2
1
1
Ceramic Capacitor
Ceramic Capacitor
D1-D10
D11
1
1
Bar Graph LED
LED
R2
R3
R4, R5, R9, R13
R6
R7, R8
R10
R12, R14
R1
R11
1
1
4
1
2
1
2
1
1
1/4 Watt Film Resistor
1/4 Watt Film Resistor
1/4 Watt Film Resistor
1/4 Watt Film Resistor
1/4 Watt Film Resistor
1/4 Watt Film Resistor
1/4 Watt Film Resistor
Trimpot
Trimpot
S1
1
U1
U2
U3
Value
Vendor
Part
1.0 µF
0.1 µF
GI
GI
MV57164
MV57124A
Bourns
Bourns
3386P-1-102
3386P-1-201
Switch
NKK
12SDP2
1
1
1
5.0 V Regulator
Bar Graph IC
Op Amp
Motorola
National
Motorola
MC78L05ACP
LM3914N
MC33274P
XDCR1
1
Pressure Sensor
Motorola
MPX2100DP
—
—
—
—
1
1
1
1
Terminal Block
Test Point Terminal (Black)
Test Point Terminal (Red)
Test Point Terminal (Yellow)
Augat
Components Corp.
Components Corp.
Components Corp.
2SV03
TP1040100
TP1040102
TP1040104
Motorola Sensor Device Data
2.7K
1.2K
1.0K
7.5K
75
820
470
1.0K
200
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3–241
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
AN1315
An Evaluation System Interfacing
the MPX2000 Series Pressure Sensors
to a Microprocessor
Prepared by: Bill Lucas
Discrete Applications Engineering
be used to evaluate any of the MPX2000 series pressure
sensors for your specific application.
Freescale Semiconductor, Inc...
INTRODUCTION
Outputs from compensated and calibrated semiconductor
pressure sensors such as the MPX2000 series devices are
easily amplified and interfaced to a microprocessor. Design
considerations and the description of an evaluation board
using a simple analog interface connected to a
microprocessor is presented here.
PURPOSE
The evaluation system shown in Figure 1 shows the ease
of operating and interfacing the MOTOROLA MPX2000 series
pressure sensors to a quad operational amplifier, which
amplifies the sensor’s output to an acceptable level for an
analog–to–digital converter. The output of the op amp is
connected to the A/D converter of the microprocessor and that
analog value is then converted to engineering units and
displayed on a liquid crystal display (LCD). This system may
DESCRIPTION
The DEVB158 evaluation system is constructed on a small
printed circuit board. Designed to be powered from a 12 Vdc
power supply, the system will display the pressure applied to
the MPX2000 series sensor in pounds per square inch (PSI)
on the liquid crystal display. Table 1 shows the pressure
sensors that may be used with the system and the pressure
range associated with that particular sensor as well as the
jumper configuration required to support that sensor. These
jumpers are installed at assembly time to correspond with the
supplied sensor. Should the user chose to evaluate a different
sensor other than that supplied with the board, the jumpers
must be changed to correspond to Table 1 for the new sensor.
The displayed pressure is scaled to the full scale (PSI) range
of the installed pressure sensor. No potentiometers are used
in the system to adjust its span and offset. This function is
performed by software.
Figure 1. DEVB158 2000 Series LCD Pressure Gauge EVB
(Board No Longer Available)
REV 1
3–242
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
The signal conditioned sensor’s zero pressure offset
voltage with no pressure applied to the sensor is empirically
computed each time power is applied to the system and stored
in RAM. The sensitivity of the MPX2000 series pressure
sensors is quite repeatable from unit to unit. There is a facility
for a small adjustment of the slope constant built into the
program. It is accomplished via jumpers J4 thru J7, and will be
explained in the OPERATION section.
Figure 2 shows the printed circuit silkscreen and Figures 3A
and 3B show the schematic for the system.
Table 1.
Sensor Type
J8
J3
J2
J1
0 –1.5
0 – 7.5
0 –15.0
0 – 30
IN
OUT
OUT
OUT
IN
IN
IN
IN
IN
IN
OUT
OUT
IN
OUT
IN
OUT
Freescale Semiconductor, Inc...
MPX2010
MPX2050
MPX2100
MPX2200
Jumpers
Input Pressure
PSI
AN1315
LCD1
U5
RP1
J1
J2
J3
R4
C6
C1
Y1
C8
TP1
C7
R15
R1
C3
R5
R8
D1
C2
D2
U3
C5
R3
R2
R10
R9
R7
R13
C4
R12
U1
U4
R6
R14
J8
XDCR1
MOTOROLA DISCRETE APPLICATIONS ENGINEERING
U2
P1
+12
GND
5.2″
R11
J4
J5
J6
J7
DEVB158
2.9″
Figure 2. Printed Circuit Silkscreen
Motorola Sensor Device Data
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3–243
Freescale Semiconductor, Inc.
AN1315
The analog section of the system can be broken down into
two subsections. These sections are the power supply and the
amplification section. The power supply section consists of a
diode, used to protect the system from input voltage reversal,
and two fixed voltage regulators. The 5 volt regulator (U3) is
used to power the microprocessor and display. The 8 volt
regulator (U4) is used to power the pressure sensor, voltage
references and a voltage offset source.
The microprocessor section (U5) requires minimal support
hardware to function. The MC34064P–5 (U2) provides an
under voltage sense function and is used to reset the
microprocessor at system power–up. The 4.0 MHz crystal
(Y1) provides the external portion of the oscillator function for
clocking the microprocessor and providing a stable base for
timing functions.
Table 2. Parts List
Designators
Description
Rating
Manufacturer
Part Number
C3, C4, C6
3
0.1 µF Ceramic Cap.
50 Vdc
Sprague
1C105Z5U104M050B
C1, C2, C5
3
1 µF Ceramic Cap.
50 Vdc
muRATA ERIE
RPE123Z5U105M050V
2
22 pF Ceramic Cap.
100 Vdc
Mepco/Centralab
CN15A220K
C7, C8
J1 – J3, J8
Freescale Semiconductor, Inc...
Quant.
3 OR 4
#22 or #24 AWG Tined Copper
As Required
J4 – J7
1
Dual Row Straight 4 Pos.
Arranged On 0.1″ Grid
AMP
87227–2
LCD1
1
Liquid Crystal Display
IEE
LCD5657
P1
1
Power Connector
Phoenix Contact
MKDS 1/2–3.81
R1
1
6.98K Ohm resistor 1%
R2
1
121 Ohm Resistor 1%
R3
1
200 Ohm Resistor 1%
R4, R11
2
4.7K Ohm Resistor
R7
1
340 Ohm Resistor 1%
R5, R6
2
2.0K Ohm Resistor 1%
R8
1
23.7 Ohm Resistor 1%
R9
1
976 Ohm Resistor 1%
R10
1
1K Ohm Resistor 1%
R12
1
3.32K Ohm Resistor 1%
R13
1
4.53K Ohm Resistor 1%
R14
1
402 Ohm Resistor 1%
R15
1
10 Meg Ohm Resistor
RP1
1
47K Ohm x 7 SIP Resistor 2%
CTS
770 Series
TP1
1
Test Point
Components Corp.
TP–104–01–02
U1
1
Quad Operational Amplifier
Motorola
MC33274P
U2
1
Under Voltage Detector
Motorola
MC34064P–5
U3
1
5 Volt Fixed Voltage Regulator
Motorola
MC78L05ACP
U4
1
8 Volt Fixed Voltage Regulator
Motorola
MC78L08ACP
U5
1
Microprocessor
Motorola
Motorola
MC68HC705B5FN or
XC68HC705B5FN
XDCR
1
Pressure Sensor
Motorola
MPX2xxxDP
Y1
1
Crystal (Low Profile)
CTS
ATS040SLV
No Designator
1
52 Pin PLCC Socket for U5
AMP
821–575–1
No Designator
4
Jumpers For J4 thru J7
Molex
15–29–1025
No Designator
1
Bare Printed Circuit Board
No Designator
4
Self Sticking Feet
Fastex
5033–01–00–5001
Red
4.0 MHz
Note: All resistors are 1/4 W resistors with a tolerance of 5% unless otherwise noted.
Note: All capacitors are 100 volt, ceramic capacitors with a tolerance of 10% unless otherwise noted.
3–244
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AN1315
OPERATIONAL CHARACTERISTICS
PIN–BY–PIN DESCRIPTION
The following operational characteristics are included as a
guide to operation.
+12:
Input power is supplied at the +12 terminal. The minimum
operating voltage is 10.75 Vdc and the maximum operating
voltage is 16 Vdc.
Characteristic
Min
Max
Unit
+12
10.75
16
Volts
Operating Current
ICC
75
mA
Full Scale Pressure
MPX2010
MPX2050
MPX2100
MPX2200
Pfs
1.5
7.5
15
30
PSI
PSI
PSI
PSI
Freescale Semiconductor, Inc...
Symbol
Power Supply Voltage
GND:
The ground terminal is the power supply return for the system.
TP1:
Test point 1 is connected to the final op amp stage. It is the
voltage that is applied to the microprocessor’s A/D converter.
There are two ports on the pressure sensor located at the
bottom center of the printed circuit board. The pressure port
is on the top left and the vacuum port is on the bottom right of
the sensor.
+12 V
J8 IS INSTALLED FOR
THE MPX2010 ONLY
5
+ 4 7
6 –U1A
+5 V
6.98K
+8
R1
2
MC33274
10 +
8
9 –U1C
3
121
R2
200
R3
1N914
4.7K
U2
R4
MC34064P–5
PD0
2–A2
GND
+5 V
12
+
14
13 –U1D
976
1K
R9
R10
7 x 47K
J1
R7
23.7
R8
SENSOR TYPE
SELECT
U3
1 µF
78L05
OUT
1 µF
GROUND
C1
J3
+5 V
+
J2
0.1
C2
C3
J4
U4
D1
+12 IN
P1
1N4002
IN
78L08
OUT
GROUND
GROUND
CPU_RESET
2–B4
TP1
340
IN
OUT
2K
2
–
1
3 +U1B
11
+
R11
+IN
D2
R6
2K
+8
4.7K
R5
J8
1
4
XDCR1
+5 V
+5 V
1 µF
J5
+8
+
0.1
C5
3.32K
R12
C4
VRH
2–D4
4.53K
SLOPE ADJ.
402
PD2
2–A3
PD3
2–A3
PD4
2–A3
PD5
2–A3
J6
PD6
2–A3
J7
PD7
2–A3
R13
VRL
2–D4
PD1
2–A2
R14
Figure 3a. Schematic
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PD7
1-E4
PD5
1-E4
PD1
1-E3
PD1
1-E3
PD6
1-E4
PD4
1-E3
PD2
1-E3
PD0
1-C2
3
4
5
9
11
12
13
14
0
PD7
PD6
PD5
PD4
PD3
PD2
PD1
47
+5 V
2
36
IRQ*
19
37
PD0
49
28
1
7
18
6
44
15
C6
5
35
VPP6
34
0.1
43
7
PORTC
RESET*
42
6
CPU_RESET
1-E2
48
5
VDD
4
10
45
8 31
46
3
32
9
41
VSS
39
0
10
2
29
22
TCAP1
37
11
38
32
26
U5
6
27
33
PORTB
7
12
34
13
23
TCAP2
21
D/A
MC68HC705B5
1
30
LCD1
5
4
50
RDI
35
14
3
52
TDO
36
15
24
31
25
0
16
2
VRL
1-C4
7
VRL
29
22
Freescale Semiconductor, Inc...
30
23
1
17
24
7
25
PORTA
18
5
20
27
VRH
1-C4
8
VRH
6
19
4
20
PLMA
26
21
3
OSC1
OSC2
28
1
BLK
PLN
16
R15
10M
17
C7
22 pF
PINS:
2–4, 33, 38–40
C8
Y1
4.00 MHz
22 pF
AN1315
Freescale Semiconductor, Inc.
Figure 3b. Schematic
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
Freescale Semiconductor, Inc...
OPERATION
Connect the system to a 12 Vdc regulated power supply.
(Note the polarity marked on the power terminal P1.)
Depending on the particular pressure sensor being used with
the system, wire jumpers J1 through J3 and J8 must be
installed at board assembly time. If at some later time it is
desirable to change the type of sensor that is installed on the
board, jumpers J1 through J3 and J8, must be reconfigured for
the system to function properly (see Table 1). If an invalid J1
through J3 jumper combination (i.e., not listed in Table 1) is
used the LCD will display “SE” to indicate that condition.
These jumpers are read by the software and are used to
determine which sensor is installed on the board. Wire jumper
J8 is installed only when an MPX2010DP pressure sensor is
used on the system. The purpose of wire jumper J8 will be
explained later in the text. Jumpers J4 through J7 are read by
the software to allow the user to adjust the slope constant used
for the engineering units calculation (see Table 3). The
pressure and vacuum ports on the sensor must be left open
to atmosphere anytime the board is powered–up. This is
because the zero pressure offset voltage is computed at
power–up.
When you apply power to the system, the LCD will display
CAL for approximately 5 seconds. After that time, pressure or
vacuum may be applied to the sensor. The system will then
start displaying the applied pressure in PSI.
Table 3.
J7
J6
J5
J4
Action
IN
IN
IN
IN
IN
IN
IN
IN
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
IN
IN
IN
IN
OUT
OUT
OUT
OUT
IN
IN
IN
IN
OUT
OUT
OUT
OUT
IN
IN
OUT
OUT
IN
IN
OUT
OUT
IN
IN
OUT
OUT
IN
IN
OUT
OUT
IN
OUT
IN
OUT
IN
OUT
IN
OUT
IN
OUT
IN
OUT
IN
OUT
IN
OUT
Normal Slope
Decrease the Slope Approximately 7%
Decrease the Slope Approximately 6%
Decrease the Slope Approximately 5%
Decrease the Slope Approximately 4%
Decrease the Slope Approximately 3%
Decrease the Slope Approximately 2%
Decrease the Slope Approximately 1%
Increase the Slope Approximately 1%
Increase the Slope Approximately 2%
Increase the Slope Approximately 3%
Increase the Slope Approximately 4%
Increase the Slope Approximately 5%
Increase the Slope Approximately 6%
Increase the Slope Approximately 7%
Normal Slope
To improve the accuracy of the system, you can change the
constant used by the program that determines the span of the
sensor and amplifier. You will need an accurate test gauge
(using PSI as the reference) to measure the pressure applied
to the sensor. Anytime after the display has completed the
zero calculation, (after CAL is no longer displayed) apply the
sensor’s full scale pressure (see Table 1), to the sensor. Make
sure that jumpers J4 through J7 are in the “normal”
configuration (see Table 3). Referring to Table 3, you can
better “calibrate” the system by changing the configuration of
J4 through J7. To “calibrate” the system, compare the display
reading against that of the test gauge (with J4 through J7 in the
Motorola Sensor Device Data
AN1315
“normal slope” configuration). Change the configuration of J4
through J7 according to Table 3 to obtain the best results. The
calibration jumpers may be changed while the system is
powered up as they are read by the software before each
display update.
DESIGN CONSIDERATIONS
To build a system that will show how to interface an
MPX2000 series pressure sensor to a microprocessor, there
are two main challenges. The first is to take a small differential
signal produced by the sensor and produce a ground
referenced signal of sufficient amplitude to drive a
microprocessor’s A/D input. The second challenge is to
understand the microprocessor’s operation and to write
software that makes the system function.
From a hardware point of view, the microprocessor portion
of the system is straight forward. The microprocessor needs
power, a clock source (crystal Y1, two capacitors and a
resistor), and a reset signal to make it function. As for the A/D
converter, external references are required to make it function.
In this case, the power source for the sensor is divided to
produce the voltage references for the A/D converter.
Accurate results will be achieved since the output from the
sensor and the A/D references are ratiometric to its power
supply voltage.
The liquid crystal display is driven by Ports A, B and C of the
microprocessor. There are enough I/O lines on these ports to
provide drive for three full digits, the backplane and two
decimal points. Software routines provide the AC waveform
necessary to drive the display.
The analog portion of the system consists of the pressure
sensor, a quad operational amplifier and the voltage
references for the microprocessor’s A/D converter and signal
conditioning circuitry. Figure 4 shows an interface circuit that
will provide a single ended signal with sufficient amplitude to
drive the microprocessor’s A/D input. It uses a quad
operational amplifier and several resistors to amplify and level
shift the sensor’s output. It is necessary to level shift the output
from the final amplifier into the A/D. Using single power
supplied op amps, the VCE saturation of the output from an op
amp cannot be guaranteed to pull down to zero volts. The
analog design shown here will provide a signal to the A/D
converter with a span of approximately 4 volts when zero to
full–scale pressure is applied to the sensor. The final
amplifier’s output is level shifted to approximately 0.7 volts.
This will provide a signal that will swing between
approximately 0.7 volts and 4.7 volts. The offset of 0.7 volts in
this implementation does not have to be trimmed to an exact
point. The software will sample the voltage applied to the A/D
converter at initial power up time and call that value “zero”. The
important thing to remember is that the span of the signal will
be approximately 4 volts when zero to full scale pressure is
applied to the sensor. The 4 volt swing in signal may vary
slightly from sensor to sensor and can also vary due to resistor
tolerances in the analog circuitry. Jumpers J4 through J7 may
be placed in various configurations to compensate for these
variations (see Table 3).
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Information On This Product,
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3–247
Freescale Semiconductor, Inc.
AN1315
+12 V
J8 IS INSTALLED FOR
THE MPX2010 ONLY
5
+ 4 7
6 –U1A
+5 V
6.98K
+8
R1
2
3
121
R2
200
R3
D2
PD0
R4
TP1
2K
R6
2K
12
+
14
13 –U1D
2
–
1
3 +U1B
11
+8
1N914
4.7K
R5
J8
1
4
XDCR1
Freescale Semiconductor, Inc...
MC33274
10
+
8
9 –U1C
340
976
1K
R9
R10
R7
23.7
R8
Figure 3.
Figure 4. Analog Interface
Referring to Figure 4, most of the amplification of the voltage
from the pressure sensor is provided by U1A which is
configured as a differential amplifier. U1B serves as a unity
gain buffer in order to keep any current that flows through R2
(and R3) from being fed back into the sensor’s negative
output. With zero pressure applied to the sensor, the
differential voltage from pin 2 to pin 4 of the sensor is zero or
very close to zero volts. The common mode, or the voltage
measured between pins 2 or 4 to ground, is equal to
approximately one half of the voltage applied to the sensor, or
4 volts. The zero pressure output voltage at pin 7 of U1A will
then be 4 volts because pin 1 of U1B is also at 4 volts, creating
a zero bias between pins 5 and 6 of U1A. The four volt zero
pressure output will then be level shifted to the desired zero
pressure offset voltage (approximately 0.7 volts) by U1C and
U1D.
To further explain the operation of the level shifting circuitry,
refer again to Figure 4. Assuming zero pressure is applied to
the sensor and the common mode voltage from the sensor is
4 volts, the voltage applied to pin 12 of U1D will be 4 volts,
implying pin 13 will be at 4 volts. The gain of amplifier U1D will
be (R10/(R8+R9)) +1 or a gain of 2. R7 will inject a Voffset (0.7
volts) into amplifier U1D, thus causing the output at U1D pin
14 to be 7.3 = (4 volts @ U1D pin 12 2) – 0.7 volts. The gain
of U1C is also set at 2 ((R5/R6)+1). With 4 volts applied to pin
10 of U1C, its output at U1C pin 8 will be 0.7 = ((4 volts @ U1C
pin 10
2) – 7.3 volts). For this scheme to work properly,
amplifiers U1C and U1D must have a gain of 2 and the output
of U1D must be shifted down by the Voffset provided by R7. In
this system, the 0.7 volts Voffset was arbitrarily picked and
could have been any voltage greater than the Vsat of the op
amp being used. The system software will take in account any
3–248
variations of Voffset as it assumes no pressure is applied to the
sensor at system power up.
The gain of the analog circuit is approximately 117. With the
values shown in Figure 4, the gain of 117 will provide a span
of approximately 4 volts on U1C pin 8 when the pressure
sensor and the 8 volt fixed voltage regulator are at their
maximum output voltage tolerance. All of the sensors listed in
Table 1 with the exception of the MPX2010DP output
approximately 33 mV when full scale pressure is applied.
When the MPX2010DP sensor is used, its full scale sensor
differential output is approximately 20 mV. J8 must be installed
to increase the gain of the analog circuit to still provide the 4
volts span out of U1C pin 8 with a 20 mV differential from the
sensor.
Diode D2 is used to protect the microprocessor’s A/D input
if the output from U1C exceeds 5.6 volts. R4 is used to provide
current limiting into D4 under failure or overvoltage conditions.
SOFTWARE
The source code, compiled listing, and S–record output for
the software used in this system are available on the Motorola
Freeware Bulletin Board Service in the MCU directory under
the filename DEVB158.ARC. To access the bulletin board,
you must have a telephone line, a 300, 1200 or 2400 baud
modem and a personal computer. The modem must be
compatible with the Bell 212A standard. Call (512) 891–3733
to access the Bulletin Board Service.
Figure 5 is a flowchart for the program that controls the
system. The software for the system consists of a number of
modules. Their functions provide the capability for system
calibration as well as displaying the pressure input to the
MPX2000 series pressure sensor.
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More Information On This Product,
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
AN1315
START
INITIALIZE DISPLAY I/O PORTS
INITIALIZE TIMER REGISTERS
DETERMINE SENSOR TYPE
ENABLE INTERRUPTS
TIMER
INTERRUPT
SERVICE TIMER REGISTERS
SETUP COUNTER FOR NEXT INTERRUPT
SERVICE LIQUID CRYSTAL DISPLAY
ACCUMULATE 100 A/D CONVERSIONS
COMPUTE INPUT PRESSURE
CONVERT TO DECIMAL/SEGMENT DATA
PLACE IN RESULT OUTPUT BUFFER
RETURN
Freescale Semiconductor, Inc...
COMPUTE SLOPE CONSTANT
Figure 5. DEVB–158 Software Flowchart
The “C” compiler used in this project was provided by BYTE
CRAFT LTD. (519) 888–6911. A compiler listing of the
program is included at the end of this document. The following
is a brief explanation of the routines:
digit decimal number in an array called “digit.” It then uses
the decimal results for each digit as an index into a table
that converts the decimal number into a segment pattern
for the display. This is then output to the display.
delay() Used to provide a software loop delay.
read_a2d() Performs 100 reads on the A/D converter on
multiplexer channel 0 and returns the accumulation.
fixcompare() Services the internal timer for 15 ms. timer
compare interrupts.
TIMERCMP() Alternates the data and backplane inputs to
the liquid crystal display.
initio() Sets up the microprocessor’s I/O ports, timer and
enables processor interrupts.
adzero() This routine is called at powerup time. It delays
to let the power supply and the transducer stabilize. It then
calls “read_atod()” and saves the returned value as the
sensors output voltage with zero pressure applied.
cvt_bin_dec(unsigned long arg) This routine converts
the unsigned binary argument passed in “arg” to a five
Motorola Sensor Device Data
display_psi() This routine is called from “main()” never to
return. The A/D converter routine is called, the pressure
is calculated based on the type sensor detected and the
pressure applied to the sensor is displayed. The loop
then repeats.
sensor_type() This routine determines the type of sensor
from reading J1 to J3, setting the full scale pressure for
that particular sensor in a variable for use by display_psi().
sensor_slope() This routine determines the slope
constant to be used by display_psi() for engineering units
output.
main() This is the main routine called from reset. It calls
“initio()” to setup the system’s I/O. “display_psi()” is called
to compute and display the pressure applied to the
sensor.
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3–249
AN1315
6805 ’C’ COMPILER V3.48
Freescale Semiconductor, Inc.
16–Oct–1991
PAGE
1
#pragma option f0;
/*
THE FOLLOWING ’C’ SOURCE CODE IS WRITTEN FOR THE DEVB158 EVALUATION
BOARD. IT WAS COMPILED WITH A COMPILER COURTESY OF:
BYTE CRAFT LTD.
421 KING ST.
WATERLOO, ONTARIO
CANADA N2J 4E4
(519)888–6911
Freescale Semiconductor, Inc...
SOME SOURCE CODE CHANGES MAY BE NECESSARY FOR COMPILATION WITH OTHER
COMPILERS.
BILL LUCAS 2/5/92
MOTOROLA, SPS
Revision history
rev. 1.0 initial release 3/19/92
rev. 1.1 added additional decimal digit to the MPX2010 sensor. Originally
resolved the output to .1 PSI. Modified cvt_bin_dec to output PSI resolved
to .01 PSI. WLL 9/25/92
0800 1700
0050 0096
*/
#pragma memory ROMPROG [5888]
#pragma memory RAMPAGE0 [150]
1FFE
1FFC
1FFA
1FF8
1FF6
1FF4
1FF2
/*
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
@ 0x0800 ;
@ 0x0050 ;
Vector assignments
*/
vector __RESET
@ 0x1ffe
vector __SWI
@ 0x1ffc
vector IRQ
@ 0x1ffa
vector TIMERCAP @ 0x1ff8
vector TIMERCMP @ 0x1ff6
vector TIMEROV
@ 0x1ff4
vector SCI
@ 0x1ff2
;
;
;
;
;
;
;
#pragma has STOP ;
#pragma has WAIT ;
#pragma has MUL ;
0000
0001
0002
0003
0004
0005
0006
0007
0008
0009
000A
000B
000C
000D
000E
000F
0010
0011
0012
0013
0014
0015
0016
0017
0018
0019
001A
001B
001C
001D
001E
001F
3–250
/*
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
#pragma
Register assignments for the 68HC705B5 microcontroller
*/
portrw porta
@ 0x00; /*
*/
portrw portb
@ 0x01; /*
*/
portrw portc
@ 0x02; /*
*/
portrw portd
@ 0x03; /* in ,–
,SS
,SCK ,MOSI ,MISO,TxD,RxD */
portrw ddra
@ 0x04; /* Data direction, Port A
*/
portrw ddrb
@ 0x05; /* Data direction, Port B
*/
portrw ddrc
@ 0x06; /* Data direction, Port C (all output)
*/
portrw eeclk
@ 0x07; /* eeprom/eclk cntl */
portrw addata @ 0x08; /* a/d data register */
portrw adstat @ 0x09; /* a/d stat/control */
portrw plma
@ 0x0a; /* pulse length modulation a */
portrw plmb
@ 0x0b; /* pulse length modulation b */
portrw misc
@ 0x0c; /* miscellaneous register */
portrw scibaud @ 0x0d; /* sci baud rate register */
portrw scicntl1 @ 0x0e; /* sci control 1 */
portrw scicntl2 @ 0x0f; /* sci control 2 */
portrw scistat @ 0x10; /* sci status reg */
portrw scidata
@ 0x11; /* SCI Data */
portrw tcr
@ 0x12; /* ICIE,OCIE,TOIE,0;0,0,IEGE,OLVL
*/
portrw tsr
@ 0x13; /* ICF,OCF,TOF,0; 0,0,0,0
*/
portrw icaphi1
@ 0x14; /* Input Capture Reg (Hi–0x14, Lo–0x15)
*/
portrw icaplo1
@ 0x15; /* Input Capture Reg (Hi–0x14, Lo–0x15)
*/
portrw ocmphi1
@ 0x16; /* Output Compare Reg (Hi–0x16, Lo–0x17) */
portrw ocmplo1
@ 0x17; /* Output Compare Reg (Hi–0x16, Lo–0x17) */
portrw tcnthi
@ 0x18; /* Timer Count Reg (Hi–0x18, Lo–0x19)
*/
portrw tcntlo
@ 0x19; /* Timer Count Reg (Hi–0x18, Lo–0x19)
*/
portrw aregnthi
@ 0x1A; /* Alternate Count Reg (Hi–$1A, Lo–$1B)
*/
portrw aregntlo
@ 0x1B; /* Alternate Count Reg (Hi–$1A, Lo–$1B)
*/
portrw icaphi2
@ 0x1c; /* Input Capture Reg (Hi–0x1c, Lo–0x1d)
*/
portrw icaplo2
@ 0x1d; /* Input Capture Reg (Hi–0x1c, Lo–0x1d)
*/
portrw ocmphi2
@ 0x1e; /* Output Compare Reg (Hi–0x1e, Lo–0x1f) */
portrw ocmplo2
@ 0x1f; /* Output Compare Reg (Hi–0x1e, Lo–0x1f) */
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For
More Information On This Product,
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
1EFE 74
AN1315
#pragma mor @ 0x1efe = 0x74; /* this disables the watchdog counter and does
not add pull–down resistors on ports B and C */
/* put constants and variables here...they must be global */
/***************************************************************************/
0800 FC 30 DA 7A 36 6E E6 38 FE
0809 3E
const char lcdtab[]={0xfc,0x30,0xda,0x7a,0x36,0x6e,0xe6,0x38,0xfe,0x3e };
/* lcd pattern table
0
1
2
3
4
5
6
7
8
9
*/
080A 27 10 03 E8 00 64 00 0A
const long dectable[] = { 10000, 1000, 100, 10 };
0050 0005
unsigned int digit[5]; /* buffer to hold results from cvt_bin_dec function */
0812 00 96 00 4B 00 96 00 1E 00
081B 67
const long type[] = {
150,
75,
150,
30,
103
};
Freescale Semiconductor, Inc...
/*
MPX2010 MPX2050 MPX2100 MPX2200 MPX2700
The table above will cause the final results of the pressure to
engineering units to display the 1.5, 7.3 and 15.0 devices with a
decimal place in the tens position. The 30 and 103 psi devices will
display in integer units.
*/
081C
0825
082E
0837
01
B0
01
DD
C2
01
CB
01
01
B4
01
E1
A2
01
CF
01
01 A7 01 AB 01
B9 01 BD 01 C6
01 D4 01 D8 01
C2
const long slope_const[]={ 450,418,423,427,432,436,441,445,454,459,
463,468,472,477,481,450 };
0000
registera areg;
/* processor’s A register */
0055
long atodtemp;
/* temp to accumulate 100 a/d readings for smoothing */
0059
long slope;
/* multiplier for adc to engineering units conversion */
005B
int adcnt;
/* a/d converter loop counter */
005C
long xdcr_offset;
/* initial xdcr offset */
005E
0060
long sensor_model; /*
int sensor_index; /*
0061 0063
unsigned long i,j; /* counter for loops */
0065
unsigned int k;
installed sensor based on J1..J3 */
determine the location of the decimal pt. */
/* misc variable */
struct bothbytes
{ int hi;
{ int lo;
};
0066 0002
0066 0002
0066 0002
0066 0002
union isboth
{ long l;
struct bothbytes b;
};
union isboth q;
/* used for timer set–up */
/***************************************************************************/
0068 0004
006C 0004
0070 0004
/* variables for add32 */
unsigned long SUM[2];
/*
unsigned long ADDEND[2]; /*
unsigned long AUGEND[2]; /*
result
one input
second input
*/
*/
*/
0074 0004
0078 0004
007C 0004
/* variables for sub32 */
unsigned long MINUE[2]; /*
unsigned long SUBTRA[2]; /*
unsigned long DIFF[2];
/*
minuend
subtrahend
difference
*/
*/
*/
0080 0004
0084 0004
0088 0004
/* variables for mul32 */
unsigned long MULTP[2]; /*
unsigned long MTEMP[2]; /*
unsigned long MULCAN[2]; /*
multiplier
*/
high order 4 bytes at return */
multiplicand at input, low 4 bytes at return */
Motorola Sensor Device Data
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3–251
Freescale Semiconductor, Inc.
AN1315
/* variables for div32 */
unsigned long DVDND[2]; /*
unsigned long DVSOR[2]; /*
unsigned long QUO[2];
/*
unsigned int CNT;
/*
008C 0004
0090 0004
0094 0004
0098
Dividend
Divisor
Quotient
Loop counter
*/
*/
*/
*/
/* The code starts here */
Freescale Semiconductor, Inc...
/***************************************************************************/
083C
083E
0840
0842
0844
0846
0848
084A
084C
084E
0850
0852
0854
B6
BB
B7
B6
B9
B7
B6
B9
B7
B6
B9
B7
81
B6
B0
B7
B6
B2
B7
B6
B2
B7
B6
B2
B7
81
086F 81
RTS
void sub32()
{
#asm
*––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––*
* Subtract two 32–bit values.
*
Input:
*
Minuend: MINUE[0..3]
*
Subtrahend: SUBTRA[0..3]
*
Output:
*
Difference: DIFF[1..0]
*––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––*
*
LDA MINUE+3
low byte
SUB SUBTRA+3
STA DIFF+3
LDA MINUE+2
medium low byte
SBC SUBTRA+2
STA DIFF+2
LDA MINUE+1
medium high byte
SBC SUBTRA+1
STA DIFF+1
LDA MINUE
high byte
SBC SUBTRA
STA DIFF
RTS
done
*
#endasm
}
6F
73
6B
6E
72
6A
6D
71
69
6C
70
68
0855 81
0856
0858
085A
085C
085E
0860
0862
0864
0866
0868
086A
086C
086E
RTS
void add32()
{
#asm
*––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––*
* Add two 32–bit values.
*
Inputs:
*
ADDEND: ADDEND[0..3] HIGH ORDER BYTE IS ADDEND+0
*
AUGEND: AUGEND[0..3] HIGH ORDER BYTE IS AUGEND+0
*
Output:
*
SUM: SUM[0..3] HIGH ORDER BYTE IS SUM+0
*––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––*
*
LDA ADDEND+3
low byte
ADD AUGEND+3
STA SUM+3
LDA ADDEND+2
medium low byte
ADC AUGEND+2
STA SUM+2
LDA ADDEND+1
medium high byte
ADC AUGEND+1
STA SUM+1
LDA ADDEND
high byte
ADC AUGEND
STA SUM
RTS
done
*
#endasm
}
77
7B
7F
76
7A
7E
75
79
7D
74
78
7C
void mul32()
{
#asm
*––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––*
* Multiply 32–bit value by a 32–bit value
*
*
*
Input:
3–252
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More Information On This Product,
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Motorola Sensor Device Data
Freescale Semiconductor, Inc...
Freescale Semiconductor, Inc.
0870
0872
0874
0876
0878
087A
087C
087E
0880
0882
0884
0886
0888
088A
088C
088E
0890
0892
0894
0896
0898
089A
089C
089E
08A0
08A2
08A4
08A6
08A8
08AA
08AC
08AD
08AF
AE
3F
3F
3F
3F
36
36
36
36
24
B6
BB
B7
B6
B9
B7
B6
B9
B7
B6
B9
B7
36
36
36
36
36
36
36
36
5A
26
81
*
Multiplier:
MULTP[0..3]
*
Multiplicand: MULCAN[0..3]
*
Output:
*
Product:
MTEMP[0..3] AND MULCAN[0..3] MTEMP[0] IS THE HIGH
*
ORDER BYTE AND MULCAN[3] IS THE LOW ORDER BYTE
*
*
THIS ROUTINE DOES NOT USE THE MUL INSTRUCTION FOR THE SAKE OF USERS NOT
*
USING THE HC(7)05 SERIES PROCESSORS.
*––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––*
*
*
LDX #32
loop counter
CLR MTEMP
clean–up for result
CLR MTEMP+1
*
CLR MTEMP+2
*
CLR MTEMP+3
*
ROR MULCAN
low but to carry, the rest one to the right
ROR MULCAN+1
*
ROR MULCAN+2
*
ROR MULCAN+3
*
MNEXT
BCC ROTATE
if carry is set, do the add
LDA MTEMP+3
*
ADD MULTP+3
*
STA MTEMP+3
*
LDA MTEMP+2
*
ADC MULTP+2
*
STA MTEMP+2
*
LDA MTEMP+1
*
ADC MULTP+1
*
STA MTEMP+1
*
LDA MTEMP
*
ADC MULTP
*
STA MTEMP
*
ROTATE ROR MTEMP
else: shift low bit to carry, the rest to the right
ROR MTEMP+1
*
ROR MTEMP+2
*
ROR MTEMP+3
*
ROR MULCAN
*
ROR MULCAN+1
*
ROR MULCAN+2
*
ROR MULCAN+3
*
DEX
bump the counter down
BNE MNEXT
done yet ?
RTS
done
20
84
85
86
87
88
89
8A
8B
18
87
83
87
86
82
86
85
81
85
84
80
84
84
85
86
87
88
89
8A
8B
D3
08B0 81
AN1315
#endasm
}
RTS
void div32()
{
#asm
08B1
08B3
08B5
08B7
08B9
08BB
08BD
3F
3F
3F
3F
A6
3D
2B
94
95
96
97
01
90
0F
08BF
08C0
08C2
08C4
08C6
08C8
4C
38
39
39
39
2B
93
92
91
90
04
*
*––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––*
* Divide 32 bit by 32 bit unsigned integer routine
*
*
Input:
*
Dividend: DVDND [+0..+3] HIGH ORDER BYTE IS DVND+0
*
Divisor:
DVSOR [+0..+3] HIGH ORDER BYTE IS DVSOR+0
*
Output:
*
Quotient: QUO [+0..+3]
HIGH ORDER BYTE IS QUO+0
*––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––*
*
CLR QUOzero result registers
CLR QUO+1
*
CLR QUO+2
*
CLR QUO+3
*
LDA #1
initial loop count
TST DVSOR
if the high order bit is set..no need to shift DVSOR
BMI DIV153
*
DIV151 INCA
bump the loop counter
ASL DVSOR+3
now shift the divisor until the high order bit = 1
ROL DVSOR+2
ROL DVSOR+1
*
ROL DVSOR
*
BMI DIV153
done if high order bit = 1
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AN1315
08CA A1 21
08CC 26 F1
*
DIV153
*
DIV163
08CE B7 98
08D0
08D2
08D4
08D6
08D8
08DA
08DC
08DE
08E0
08E2
08E4
08E6
08E8
B6
B0
B7
B6
B2
B7
B6
B2
B7
B6
B2
B7
24
8F
93
8F
8E
92
8E
8D
91
8D
8C
90
8C
1B
08EA
08EC
08EE
08F0
08F2
08F4
08F6
08F8
08FA
08FC
08FE
0900
0902
B6
BB
B7
B6
B9
B7
B6
B9
B7
B6
B9
B7
98
8F
93
8F
8E
92
8E
8D
91
8D
8C
90
8C
0903
0905
0906
0908
090A
090C
090E
0910
0912
0914
0916
0918
091A
20
99
39
39
39
39
34
36
36
36
3A
26
81
01
CMP
BNE
#33
DIV151
have we shifted all possible bits in the DVSOR yet ?
no
STA
CNT
save the loop counter so we can do the divide
LDA
SUB
STA
LDA
SBC
STA
LDA
SBC
STA
LDA
SBC
STA
BCC
DVDND+3
DVSOR+3
DVDND+3
DVDND+2
DVSOR+2
DVDND+2
DVDND+1
DVSOR+1
DVDND+1
DVDND
DVSOR
DVDND
DIV165
sub 32 bit divisor from dividend
*
*
*
*
*
*
*
*
*
*
*
carry is clear if DVSOR was larger than DVDND
LDA
ADD
STA
LDA
ADC
STA
LDA
ADC
STA
LDA
ADC
STA
CLC
DVDND+3
DVSOR+3
DVDND+3
DVDND+2
DVSOR+2
DVDND+2
DVDND+1
DVSOR+1
DVDND+1
DVDND
DVSOR
DVDND
add the divisor back...was larger than the dividend
*
*
*
*
*
*
*
*
*
*
*
this will clear the respective bit in QUO due to
the need to add DVSOR back to DVND
Freescale Semiconductor, Inc...
*
*
DIV165
DIV167
97
96
95
94
90
91
92
93
98
B6
BRA DIV167
SEC
ROL QUO+3
ROL QUO+2
ROL QUO+1
ROL QUO
LSR DVSOR
ROR DVSOR+1
ROR DVSOR+2
ROR DVSOR+3
DEC CNT
BNE DIV163
RTSyes
this will set the respective bit in QUO
set or clear the low order bit in QUO based on above
*
*
*
divide the divisor by 2
*
*
*
bump the loop counter down
finished yet ?
*
091B 81
#endasm
}
RTS
/***************************************************************************/
/* These interrupts are not used...give them a graceful return if for
some reason one occurs */
1FFC
091C
1FFA
091D
1FF8
091E
1FF4
091F
1FF2
0920
09
80
09
80
09
80
09
80
09
80
1C
__SWI(){}
RTI
1D
IRQ(){}
RTI
1E
TIMERCAP(){}
RTI
1F
TIMEROV(){}
RTI
20
SCI(){}
RTI
/***************************************************************************/
0921
0923
0925
0927
0929
092B
B6
A4
B7
34
B6
A1
3–254
03
0E
65
65
65
04
LDA
AND
STA
LSR
LDA
CMP
$03
#$0E
$65
$65
$65
#$04
void sensor_type()
{
k = portd & 0x0e; /* we only care about bits 1..3 */
k = k >> 1;
if ( k > 4 )
/* right justify the variable */
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Freescale Semiconductor, Inc.
092D 23 0C
BLS
$093B
092F
0931
0933
0935
0937
0939
3F
A6
B7
A6
B7
20
02
6E
01
CE
00
FE
CLR
LDA
STA
LDA
STA
BRA
$02
#$6E
$01
#$CE
$00
$0939
093B
093D
093F
0940
0941
0944
0946
0949
094B
B6
B7
97
58
D6
B7
D6
B7
81
65
60
LDA
STA
TAX
LSLX
LDA
STA
LDA
STA
RTS
$65
$60
08 12
5E
08 13
5F
AN1315
{ /* we have a set–up error in wire jumpers J1 – J3 */
portc = 0;
/*
*/
portb = 0x6e; /* S */
porta = 0xce;
/* E */
while(1);
}
sensor_index = k;
sensor_model = type[k];
$0812,X
$5E
$0813,X
$5F
}
Freescale Semiconductor, Inc...
/***************************************************************************/
094C
094E
0950
0952
0954
0956
0958
095A
095C
095D
0960
0962
0965
0967
B6
A4
B7
34
34
34
34
BE
58
D6
B7
D6
B7
81
03
F0
65
65
65
65
65
65
08 1C
59
08 1D
5A
LDA
AND
STA
LSR
LSR
LSR
LSR
LDX
LSLX
LDA
STA
LDA
STA
RTS
$03
#$F0
$65
$65
$65
$65
$65
$65
void sensor_slope()
{
k=portd & 0xf0; /* we only care about bits 4..7 */
k = k >> 4;
/* right justify the variable */
slope = slope_const[k];
$081C,X
$59
$081D,X
$5A
}
/***************************************************************************/
0968
096A
096C
096E
0970
0972
0974
0976
0978
097A
097C
097E
3F
3F
B6
A0
B6
A2
24
3C
26
3C
20
81
62
61
62
20
61
4E
08
62
02
61
EE
CLR
CLR
LDA
SUB
LDA
SBC
BCC
INC
BNE
INC
BRA
RTS
$62
$61
$62
#$20
$61
#$4E
$097E
$62
$097C
$61
$096C
void delay(void) /* just hang around for a while */
{
for (i=0; i<20000; ++i);
}
/***************************************************************************/
read_a2d(void)
{
/* read the a/d converter on channel 5 and accumulate the result
in atodtemp */
097F
0981
0983
0985
0987
0989
098B
3F
3F
3F
B6
A8
A1
24
56
55
5B
5B
80
E4
21
CLR
CLR
CLR
LDA
EOR
CMP
BCC
$56
$55
$5B
$5B
#$80
#$E4
$09AE
098D
098F
0991
0994
0996
0998
A6
B7
0F
B6
3F
B7
20
09
09 FD
08
57
58
LDA
#$20
STA
$09
BRCLR 7,$09,$0991
LDA
$08
CLR
$57
STA
$58
Motorola Sensor Device Data
atodtemp=0;
/* zero for accumulation */
for ( adcnt = 0 ; adcnt<100; ++adcnt) /* do 100 a/d conversions */
{
adstat = 0x20;
/* convert on channel 0 */
while (!(adstat & 0x80)); /* wait for a/d to complete */
atodtemp = addata + atodtemp;
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AN1315
099A
099C
099E
09A0
09A2
09A4
09A6
09A8
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B7
B6
B9
B7
B7
B6
B7
56
58
57
55
57
55
58
56
ADD
STA
LDA
ADC
STA
STA
LDA
STA
$56
$58
$57
$55
$57
$55
$58
$56
09AA
09AC
09AE
09B0
09B2
09B4
09B6
09B8
09BA
09BC
09BF
09C2
09C4
09C6
3C
20
B6
B7
B6
B7
3F
A6
B7
CD
CD
BF
B7
81
5B
D7
56
58
55
57
9A
64
9B
0B F1
0C 22
55
56
INC
BRA
LDA
STA
LDA
STA
CLR
LDA
STA
JSR
JSR
STX
STA
RTS
$5B
$0985
$56
$58
$55
$57
$9A
#$64
$9B
$0BF1
$0C22
$55
$56
Freescale Semiconductor, Inc...
}
atodtemp = atodtemp/100;
return atodtemp;
}
/***************************************************************************/
09C7
09C9
09CB
09CD
09CF
09D1
09D3
09D5
09D7
09D9
09DB
09DD
09DF
09E1
B6
B7
B6
B7
AB
B7
B6
A9
B7
B7
B6
B6
B7
81
18
66
19
67
4C
67
66
1D
66
16
13
67
17
LDA
STA
LDA
STA
ADD
STA
LDA
ADC
STA
STA
LDA
LDA
STA
RTS
$18
$66
$19
$67
#$4C
$67
$66
#$1D
$66
$16
$13
$67
$17
void fixcompare (void)
{
q.b.hi =tcnthi;
/* sets–up the timer compare for the next interrupt */
q.b.lo = tcntlo;
q.l +=7500;
/* ((4mhz xtal/2)/4) = counter period = 2us.*7500 = 15ms. */
ocmphi1 = q.b.hi;
areg=tsr; /* dummy read */
ocmplo1 = q.b.lo;
}
/***************************************************************************/
1FF6
09E2
09E4
09E6
09E8
09EA
09
33
33
33
AD
80
E2
02
01
00
DD
COM
COM
COM
BSR
RTI
$02
$01
$00
$09C7
void TIMERCMP (void)
/* timer service module */
{
portc =~ portc;
/* service the lcd by inverting the ports */
portb =~ portb;
porta =~ porta;
fixcompare();
}
/***************************************************************************/
void adzero(void)
/* called by initio() to save initial xdcr’s zero
pressure offset voltage output */
{
09EB
09ED
09EF
09F1
09F3
09F5
09F7
3F
3F
B6
A0
B6
A2
24
64
63
64
14
63
00
0B
CLR
CLR
LDA
SUB
LDA
SBC
BCC
$64
$63
$64
#$14
$63
#$00
$0A04
for ( j=0; j<20; ++j)
/* give the sensor time to ”warm–up” and the
power supply time to settle down */
{
09F9 CD 09 68
JSR
$0968
delay();
}
09FC
09FE
0A00
0A02
0A04
3C
26
3C
20
CD
3–256
64
02
63
EB
09 7F
INC
BNE
INC
BRA
JSR
$64
$0A02
$63
$09EF
$097F
xdcr_offset =
read_a2d();
www.motorola.com/semiconductors
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More Information On This Product,
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0A07 3F 5C
0A09 B7 5D
0A0B 81
CLR
STA
RTS
AN1315
$5C
$5D
}
Freescale Semiconductor, Inc...
/***************************************************************************/
0A0C
0A0E
0A10
0A12
0A14
0A16
0A18
0A1A
0A1C
0A1E
0A20
0A22
0A24
0A26
0A28
0A2A
0A2C
A6
B7
3F
3F
3F
A6
B7
B7
B7
B6
3F
3F
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A6
B7
9A
20
09
02
01
00
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06
05
04
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16
1F
9F
40
12
0A2D
0A2F
0A31
0A33
0A35
0A37
0A39
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0A3E
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B7
A6
B7
A6
B7
CD
AD
81
CC
02
BE
01
C4
00
09 21
AD
LDA
STA
CLR
CLR
CLR
LDA
STA
STA
STA
LDA
CLR
CLR
LDA
BSR
LDA
STA
CLI
#$20
$09
$02
$01
$00
#$FF
$06
$05
$04
$13
$1E
$16
$1F
$09C7
#$40
$12
LDA
STA
LDA
STA
LDA
STA
JSR
BSR
RTS
#$CC
$02
#$BE
$01
#$C4
$00
$0921
$09EB
void initio (void)
/* setup the I/O */
{
adstat = 0x20; /* power–up the A/D */
porta = portb = portc = 0;
ddra = ddrb = ddrc = 0xff;
areg=tsr; /* dummy read */
ocmphi1 = ocmphi2 = 0;
areg = ocmplo2; /* clear out output compare 2 if it happens to be set */
fixcompare(); /* set–up for the first timer interrupt */
tcr = 0x40;
CLI; /* let the interrupts begin !
/* write CAL to the display */
portc = 0xcc; /* C */
*/
portb = 0xbe; /* A */
porta = 0xc4; /* L */
sensor_type(); /* get the model of the sensor based on J1..J3 */
adzero(); /* auto zero */
}
/***************************************************************************/
void cvt_bin_dec(unsigned long arg)
/* First converts the argument to a five digit decimal value. The msd is in
the lowest address. Then leading zero suppress the value and write it to the
display ports.
The argument value is 0..65535 decimal. */
009D
0A3F
0A41
009F
00A0
0A43
0A45
0A47
0A49
{
BF 9D
B7 9E
3F
B6
A1
24
STX
STA
$9D
$9E
9F
9F
05
07
CLR
LDA
CMP
BCC
$9F
$9F
#$05
$0A52
0A4B 97
0A4C 6F 50
TAX
CLR
$50,X
0A4E
0A50
0A52
0A54
0A56
0A58
3C
20
3F
B6
A1
24
9F
F3
9F
9F
04
7A
INC
BRA
CLR
LDA
CMP
BCC
$9F
$0A45
$9F
$9F
#$04
$0AD4
0A5A
0A5B
0A5C
0A5F
0A61
0A63
0A65
0A67
0A69
0A6C
0A6E
97
58
D6
B0
B7
B6
A8
B7
D6
A8
B2
08 0B
9E
58
9D
80
57
08 0A
80
57
TAX
LSLX
LDA
SUB
STA
LDA
EOR
STA
LDA
EOR
SBC
char i;
unsigned long l;
for ( i=0; i < 5; ++i )
{
digit[i] = 0x0;
/* put blanks in all digit positions */
}
for ( i=0; i < 4; ++i )
{
if ( arg
>= dectable [i] )
$080B,X
$9E
$58
$9D
#$80
$57
$080A,X
#$80
$57
Motorola Sensor Device Data
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Information On This Product,
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AN1315
0A70 BA 58
0A72 22 5C
ORA
BHI
$58
$0AD0
0A74
0A76
0A77
0A7A
0A7C
0A7F
0A81
0A83
0A85
0A87
0A89
0A8B
0A8D
0A8F
0A91
0A94
0A97
0A99
0A9B
0A9D
0A9F
0AA1
0AA3
0AA5
0AA7
0AA9
0AAB
0AAD
0AAF
0AB2
0AB4
0AB6
0AB8
0ABA
0ABC
0ABE
0AC0
0AC2
0AC4
0AC6
0AC8
0ACA
0ACC
0ACE
LDX
LSLX
LDA
STA
LDA
STA
LDA
STA
LDA
STA
LDA
STA
LDA
STA
JSR
JSR
STX
STA
LDX
STA
LDX
LDA
CLR
STA
LDA
STA
LDA
STA
JSR
STX
STA
COM
NEG
BNE
INC
LDA
ADD
STA
LDA
ADC
STA
STA
LDA
STA
$9F
Freescale Semiconductor, Inc...
{
BE
58
D6
B7
D6
B7
B6
B7
B6
B7
B6
B7
B6
B7
CD
CD
BF
B7
BE
E7
BE
E6
3F
B7
B6
B7
B6
B7
CD
BF
B7
33
30
26
3C
B6
BB
B7
B6
B9
B7
B7
B6
B7
9F
08
A0
08
A1
9E
58
9D
57
A0
9A
A1
9B
0B
0C
57
58
9F
50
9F
50
57
58
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9A
A1
9B
0B
57
58
57
58
02
57
58
9E
58
57
9D
57
9D
58
9E
0A
0B
F1
22
D2
l = dectable[i];
$080A,X
$A0
$080B,X
$A1
$9E
$58
$9D
$57
$A0
$9A
$A1
$9B
$0BF1
$0C22
$57
$58
$9F
$50,X
$9F
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$57
$58
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$9A
$A1
$9B
$0BD2
$57
$58
$57
$58
$0ABE
$57
$58
$9E
$58
$57
$9D
$57
$9D
$58
$9E
digit[i] = arg / l;
arg = arg–(digit[i] * l);
}
}
0AD0
0AD2
0AD4
0AD6
0AD8
0ADA
0ADC
0ADE
0AE0
3C
20
B6
B7
B6
B7
BE
B6
E7
0AE2
0AE3
0AE5
0AE7
0AE9
0AEB
0AED
0AF0
0AF2
0AF4
0AF6
0AF8
0AFA
0AFC
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0B00
9B
3D
26
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26
3D
26
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3–258
9F
80
9E
58
9D
57
9F
58
50
INC
BRA
LDA
STA
LDA
STA
LDX
LDA
STA
52
04
02
07
52
08 00
02
52
08
53
04
01
07
53
08 00
SEI
TST
BNE
CLR
BRA
LDX
LDA
STA
TST
BNE
TST
BNE
CLR
BRA
LDX
LDA
$9F
$0A54
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$58
$9D
$57
$9F
$58
$50,X
$52
$0AEB
$02
$0AF2
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$52
$0AFE
$53
$0AFE
$01
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digit[i] = arg;
/* now zero suppress and send the lcd pattern to the display */
SEI;
if ( digit[2] == 0 )
/* leading zero suppression */
portc = 0;
else
portc = ( lcdtab[digit[2]] );
/* 100’s digit */
if ( digit[2] == 0 && digit[3] == 0 )
portb=0;
else
portb = ( lcdtab[digit[3]] );
/* 10’s digit */
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More Information On This Product,
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Motorola Sensor Device Data
Freescale Semiconductor, Inc...
Freescale Semiconductor, Inc.
0B03
0B05
0B07
0B0A
B7
BE
D6
B7
01
54
08 00
00
STA
LDX
LDA
STA
$01
$54
$0800,X
$00
0B0C
0B0E
0B10
0B12
0B14
0B16
0B19
0B1A
0B1C
0B1E
B6
A8
A1
24
BE
D6
4C
B7
3D
26
60
80
83
08
54
08 00
LDA
EOR
CMP
BCC
LDX
LDA
INCA
STA
TST
BNE
$60
#$80
#$83
$0B1C
$54
$0800,X
0B20
0B22
0B25
0B27
0B29
0B2C
0B2D
BE
D6
B7
BE
D6
4C
B7
00
60
0F
54
08 00
00
53
08 00
01
LDX
LDA
STA
LDX
LDA
INCA
STA
porta = ( lcdtab[digit[4]] );
AN1315
/* 1’s digit */
/* place the decimal point only if the sensor is 15 psi or 7.5 psi */
if ( sensor_index < 3 )
porta = ( lcdtab[digit[4]]+1 ); /* add the decimal point to the lsd */
$00
$60
$0B2F
if(sensor_index ==0) /* special case */
{
porta = ( lcdtab[digit[4]] ); /* get rid of the decimal at lsd */
$54
$0800,X
$00
$53
$0800,X
portb = ( lcdtab[digit[3]]+1 ); /* decimal point at middle digit */
$01
}
0B2F 9A
0B30 CD 09 68
0B33 81
CLI
JSR
RTS
CLI;
$0968
delay();
}
/****************************************************************/
void display_psi(void)
/*
At power–up it is assumed that the pressure or vacuum port of
the sensor is open to atmosphere. The code in initio() delays
for the sensor and power supply to stabilize. One hundred A/D
conversions are averaged. That result is called xdcr_offset.
This routine calls the A/D routine which performs one hundred
conversions, divides the result by 100 and returns the value.
If the value returned is less than or equal to the xdcr_offset,
the value of xdcr_offset is substituted. If the value returned
is greater than xdcr_offset, xdcr_offset is subtracted from the
returned value.
*/
0B34
0B37
0B39
0B3B
0B3D
0B3F
0B41
0B43
0B45
0B47
0B49
0B4B
0B4D
0B4F
0B51
0B53
0B55
0B57
0B59
0B5B
0B5D
0B5F
0B61
0B63
0B66
0B68
0B6A
0B6C
0B6E
CD
3F
B7
B0
B7
B6
A8
B7
B6
A8
B2
BA
22
B6
B7
B6
B7
B6
B0
B7
B6
B2
B7
CD
B6
B7
B6
B7
B6
09 7F
55
56
5D
58
5C
80
57
55
80
57
58
08
5C
55
5D
56
56
5D
56
55
5C
55
09 4C
56
58
55
57
5E
JSR
CLR
STA
SUB
STA
LDA
EOR
STA
LDA
EOR
SBC
ORA
BHI
LDA
STA
LDA
STA
LDA
SUB
STA
LDA
SBC
STA
JSR
LDA
STA
LDA
STA
LDA
$097F
$55
$56
$5D
$58
$5C
#$80
$57
$55
#$80
$57
$58
$0B57
$5C
$55
$5D
$56
$56
$5D
$56
$55
$5C
$55
$094C
$56
$58
$55
$57
$5E
Motorola Sensor Device Data
{
while(1)
{
atodtemp = read_a2d();
/* atodtemp = raw a/d ( 0..255 ) */
if ( atodtemp <= xdcr_offset )
atodtemp = xdcr_offset;
atodtemp –=
xdcr_offset; /* remove the offset */
sensor_slope(); /* establish the slope constant for this output */
atodtemp *= sensor_model;
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3–259
Freescale Semiconductor, Inc.
Freescale Semiconductor, Inc...
AN1315
0B70
0B72
0B74
0B76
0B79
0B7B
0B7D
0B7F
0B81
0B83
0B85
0B86
0B88
0B8A
0B8C
0B8E
0B90
0B92
0B94
0B97
0B99
0B9B
0B9D
0B9F
0BA1
0BA3
0BA5
0BA7
0BA9
0BAB
0BAD
0BAF
0BB1
0BB3
0BB5
0BB8
0BBA
0BBC
0BBE
0BC0
0BC2
0BC5
0BC8
B7
B6
B7
CD
BF
B7
3F
3F
3F
3F
9F
B7
B6
B7
B6
B7
B6
B7
CD
3F
A6
B7
A6
B7
A6
B7
B6
B7
B6
B7
B6
B7
B6
B7
CD
B6
B7
B6
B7
BE
CD
CC
81
9A
5F
9B
0B D2
55
56
89
88
81
80
82
56
83
59
8A
5A
8B
08
90
01
91
86
92
A0
93
88
8C
89
8D
8A
8E
8B
8F
08
96
55
97
56
55
0A
0B
70
B1
3F
34
STA
LDA
STA
JSR
STX
STA
CLR
CLR
CLR
CLR
TXA
STA
LDA
STA
LDA
STA
LDA
STA
JSR
CLR
LDA
STA
LDA
STA
LDA
STA
LDA
STA
LDA
STA
LDA
STA
LDA
STA
JSR
LDA
STA
LDA
STA
LDX
JSR
JMP
RTS
$9A
$5F
$9B
$0BD2
$55
$56
$89
$88
$81
$80
MULTP[0] = MULCAN[0] = 0;
MULTP[1] = atodtemp;
$82
$56
$83
$59
$8A
$5A
$8B
$0870
$90
#$01
$91
#$86
$92
#$A0
$93
$88
$8C
$89
$8D
$8A
$8E
$8B
$8F
$08B1
$96
$55
$97
$56
$55
$0A3F
$0B34
MULCAN[1] = slope;
mul32();
/* analog value * slope based on J1 through J3 */
DVSOR[0] = 1;
/* now divide by 100000 */
DVSOR[1] = 0x86a0;
DVDND[0] = MULCAN[0];
DVDND[1] = MULCAN[1];
div32();
atodtemp = QUO[1]; /* convert to psi */
cvt_bin_dec( atodtemp ); /* convert to decimal and display */
}
}
/***************************************************************************/
0BC9
0BCC
0BCF
0BD1
0BD2
0BD4
0BD6
0BD7
0BD9
0BDB
0BDD
0BDF
0BE0
0BE2
0BE4
0BE6
0BE8
0BE9
0BEB
0BED
0BEE
0BF0
0BF1
0BF3
0BF4
0BF6
0BF8
0BF9
CD
CD
20
81
BE
B6
42
B7
BF
BE
B6
42
BB
B7
BE
B6
42
BB
B7
97
B6
81
3F
5F
3F
3F
5C
38
3–260
0A 0C
0B 34
FE
58
9B
A4
A5
57
9B
A5
A5
58
9A
A5
A5
A4
A4
A2
A3
58
JSR
JSR
BRA
RTS
LDX
LDA
MUL
STA
STX
LDX
LDA
MUL
ADD
STA
LDX
LDA
MUL
ADD
STA
TAX
LDA
RTS
CLR
CLRX
CLR
CLR
INCX
LSL
$0A0C
$0B34
$0BCF
void main()
{
initio(); /* set–up the processor’s i/o */
display_psi();
while(1);
/* should never get back to here */
}
$58
$9B
$A4
$A5
$57
$9B
$A5
$A5
$58
$9A
$A5
$A5
$A4
$A4
$A2
$A3
$58
www.motorola.com/semiconductors
For
More Information On This Product,
Go to: www.freescale.com
Motorola Sensor Device Data
Freescale Semiconductor, Inc...
Freescale Semiconductor, Inc.
0BFB
0BFD
0BFF
0C01
0C03
0C05
0C07
0C09
0C0B
0C0D
0C0F
0C11
0C13
0C15
0C17
0C19
0C1B
0C1C
0C1D
0C1F
0C21
0C22
0C23
0C24
0C26
0C27
1FFE
39
39
39
B6
B0
B7
B6
B2
B7
24
B6
BB
B7
B6
B9
B7
99
59
39
24
81
53
9F
BE
53
81
0B
57
A2
A3
A2
9B
A2
A3
9A
A3
0D
9B
A2
A2
9A
A3
A3
A4
D8
A4
ROL
ROL
ROL
LDA
SUB
STA
LDA
SBC
STA
BCC
LDA
ADD
STA
LDA
ADC
STA
SEC
ROLX
ROL
BCC
RTS
COMX
TXA
LDX
COMX
RTS
AN1315
$57
$A2
$A3
$A2
$9B
$A2
$A3
$9A
$A3
$0C1C
$9B
$A2
$A2
$9A
$A3
$A3
$A4
$0BF9
$A4
C9
SYMBOL TABLE
LABEL
VALUE
LABEL
VALUE
LABEL
VALUE
LABEL
VALUE
ADDEND
DIV151
DIV167
MINUE
MULTP
SUBTRA
TIMEROV
__MUL
__STARTUP
__longAC
adstat
arg
cvt_bin_dec
dectable
div32
i
icaplo2
k
main
ocmphi2
plmb
portd
scicntl1
sensor_index
slope
tcntlo
xdcr_offset
006C
08BF
0906
0074
0080
0078
091F
0000
0000
0057
0009
009D
0A3F
080A
08B1
0061
001D
0065
0BC9
001E
000B
0003
000E
0060
0059
0019
005C
AUGEND
DIV153
DVDND
MNEXT
QUO
SUM
__LDIV
__MUL16x16
__STOP
adcnt
adzero
atodtemp
ddra
delay
eeclk
icaphi1
initio
l
misc
ocmplo1
porta
q
scicntl2
sensor_model
slope_const
tcr
0070
08CE
008C
0882
0094
0068
0BF1
0BD2
0000
005B
09EB
0055
0004
0968
0007
0014
0A0C
0000
000C
0017
0000
0066
000F
005E
081C
0012
CNT
DIV163
DVSOR
MTEMP
ROTATE
TIMERCAP
__LongIX
__RDIV
__SWI
add32
aregnthi
b
ddrb
digit
fixcompare
icaphi2
isboth
lcdtab
mul32
ocmplo2
portb
read_a2d
scidata
sensor_slope
sub32
tsr
0098
08D0
0090
0084
089C
091E
009A
0C22
091C
083C
001A
0000
0005
0050
09C7
001C
0002
0800
0870
001F
0001
097F
0011
094C
0856
0013
DIFF
DIV165
IRQ
MULCAN
SCI
TIMERCMP
__MAIN
__RESET
__WAIT
addata
aregntlo
bothbytes
ddrc
display_psi
hi
icaplo1
j
lo
ocmphi1
plma
portc
scibaud
scistat
sensor_type
tcnthi
type
007C
0905
091D
0088
0920
09E2
0BC9
1FFE
0000
0008
001B
0002
0006
0B34
0000
0015
0063
0001
0016
000A
0002
000D
0010
0921
0018
0812
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
MEMORY USAGE MAP (’X’ = Used, ’–’ = Unused)
0800
0840
0880
08C0
:
:
:
:
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
0900
0940
0980
09C0
:
:
:
:
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
0A00
0A40
0A80
0AC0
:
:
:
:
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
Motorola Sensor Device Data
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Information On This Product,
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3–261
Freescale Semiconductor, Inc.
AN1315
0B00
0B40
0B80
0BC0
:
:
:
:
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
0C00
0C40
0C80
0CC0
:
:
:
:
XXXXXXXXXXXXXXXX
––––––––––––––––
––––––––––––––––
––––––––––––––––
XXXXXXXXXXXXXXXX
––––––––––––––––
––––––––––––––––
––––––––––––––––
XXXXXXXX––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
1E00
1E40
1E80
1EC0
:
:
:
:
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––X–
1F00
1F40
1F80
1FC0
:
:
:
:
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––––––––––––––––
––XXXXXXXXXXXXXX
Freescale Semiconductor, Inc...
All other memory blocks unused.
Errors
Warnings
3–262
:
:
0
0
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Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
AN1316
Frequency Output Conversion for MPX2000
Series Pressure Sensors
Prepared by: Jeff Baum
Discrete Applications Engineering
Freescale Semiconductor, Inc...
INTRODUCTION
Typically, a semiconductor pressure transducer converts
applied pressure to a “low–level” voltage signal. Current
technology enables this sensor output to be temperature
compensated and amplified to higher voltage levels on a
single silicon integrated circuit (IC). While on–chip
temperature compensation and signal conditioning certainly
provide a significant amount of added value to the basic
sensing device, one must also consider how this final output
will be used and/or interfaced for further processing. In most
sensing systems, the sensor signal will be input to additional
analog circuitry, control logic, or a microcontroller unit (MCU).
MCU–based systems have become extremely cost
effective. The level of intelligence which can be obtained for
only a couple of dollars, or less, has made relatively simple
8–bit microcontrollers the partner of choice for semiconductor
pressure transducers. In order for the sensor to communicate
its pressure–dependent voltage signal to the microprocessor,
the MCU must have an analog–to–digital converter (A/D) as
an on–chip resource or an additional IC packaged A/D. In the
latter case, the A/D must have a communications interface
that is compatible with one of the MCU’s communications
protocols. MCU’s are adept at detecting logic–level transitions
that occur at input pins designated for screening such events.
As an alternative to the conventional A/D sensor/MCU
interface, one can measure either a period (frequency) or
pulse width of an incoming square or rectangular wave signal.
Common MCU timer subsystem clock frequencies permit
temporal measurements with resolution of hundreds of
nanoseconds. Thus, one is capable of accurately measuring
the the frequency output of a device that is interfaced to such
a timer channel. If sensors can provide a frequency modulated
signal that is linearly proportional to the applied pressure
being measured, then an accurate, inexpensive (no A/D)
MCU–based sensor system is a viable solution to many
challenging sensing applications. Besides the inherent cost
savings of such a system, this design concept offers additional
benefits to remote sensing applications and sensing in
electrically noisy environments.
Figure 1. DEVB160 Frequency Output Sensor EVB
(Board No Longer Available)
REV 2
Motorola Sensor Device Data
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3–263
AN1316
Freescale Semiconductor, Inc.
The following sections will detail the design issues involved
in such a system architecture, and will provide an example
circuit which has been developed as an evaluation tool for
frequency output pressure sensor applications.
Freescale Semiconductor, Inc...
DESIGN CONSIDERATIONS
Signal Conditioning
Motorola’s MPX2000 Series sensors are temperature
compensated and calibrated – i.e. – offset and full–scale span
are precision trimmed – pressure transducers. These sensors
are available in full–scale pressure ranges from 10 kPa (1.5
psi) to 200 kPa (30 psi). Although the specifications in the data
sheets apply only to a 10 V supply voltage, the output of these
devices is ratiometric with the supply voltage. At the absolute
maximum supply voltage specified, 16 V, the sensor will
produce a differential output voltage of 64 mV at the rated
full–scale pressure of the given sensor. One exception to this
is that the full–scale span of the MPX2010 (10 kPa sensor) will
be only 40 mV due to a slightly lower sensitivity. Since the
maximum supply voltage produces the most output voltage,
it is evident that even the best case scenario will require some
signal conditioning to obtain a usable voltage level.
Many different “instrumentation–type” amplifier circuits can
satisfy the signal conditioning needs of these devices.
Depending on the precision and temperature performance
demanded by a given application, one can design an amplifier
circuit using a wide variety of operational amplifier (op amp)
IC packages with external resistors of various tolerances, or
a precision–trimmed integrated instrumentation amplifier IC.
In any case, the usual goal is to have a single–ended supply,
“rail–to–rail” output (i.e. use as much of the range from ground
to the supply voltage as possible, without saturating the op
amps). In addition, one may need the flexibility of performing
zero–pressure offset adjust and full–scale pressure
calibration. The circuitry or device used to accomplish the
voltage–to–frequency conversion will determine if, how, and
where calibration adjustments are needed. See Evaluation
Board Circuit Description section for details.
Voltage–to–Frequency Conversion
Since most semiconductor pressure sensors provide a
voltage output, one must have a means of converting this
voltage signal to a frequency that is proportional to the sensor
output voltage. Assuming the analog voltage output of the
sensor is proportional to the applied pressure, the resultant
3–264
frequency will be linearly related to the pressure being
measured. There are many different timing circuits that can
perform voltage–to–frequency conversion. Most of the
“simple” (relatively low number of components) circuits do not
provide the accuracy or the stability needed for reliably
encoding
a
signal
quantity.
Fortunately,
many
voltage–to–frequency (V/F) converter IC’s are commercially
available that will satisfy this function.
Switching Time Reduction
One limitation of some V/F converters is the less than
adequate switching transition times that effect the pulse or
square–wave frequency signal. The required switching speed
will be determined by the hardware used to detect the
switching edges. The Motorola family of microcontrollers have
input–capture functions that employ “Schmitt trigger–like”
inputs with hysteresis on the dedicated input pins. In this case,
slow rise and fall times will not cause an input capture pin to
be in an indeterminate state during a transition. Thus, CMOS
logic instability and significant timing errors will be prevented
during slow transitions. Since the sensor’s frequency output
may be interfaced to other logic configurations, a designer’s
main concern is to comply with a worst–case timing scenario.
For high–speed CMOS logic, the maximum rise and fall times
are typically specified at several hundreds of nanoseconds.
Thus, it is wise to speed up the switching edges at the output
of the V/F converter. A single small–signal FET and a resistor
are all that is required to obtain switching times below 100 ns.
APPLICATIONS
Besides eliminating the need for an A/D converter, a
frequency output is conducive to applications in which the
sensor output must be transmitted over long distances, or
when the presence of noise in the sensor environment is likely
to corrupt an otherwise healthy signal. For sensor outputs
encoded as a voltage, induced noise from electromagnetic
fields will contaminate the true voltage signal. A frequency
signal has greater immunity to these noise sources and can
be effectively filtered in proximity to the MCU input. In other
words, the frequency measured at the MCU will be the
frequency transmitted at the output of a sensor located
remotely. Since high–frequency noise and 50–60 Hz line
noise are the two most prominent sources for contamination
of instrumentation signals, a frequency signal with a range in
the low end of the kHz spectrum is capable of being well
filtered prior to being examined at the MCU.
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AN1316
Table 1. Specifications
Characteristics
Max
Units
30
Volts
– MPX2010
10
kPa
– MPX2050
50
kPa
– MPX2100
100
kPa
– MPX2200
200
kPa
Power Supply Voltage
Full Scale Pressure
Min
B+
10
Zero Pressure Offset
Sensitivity
Quiescent Current
fFS
10
kHz
fOFF
1
kHz
SAOUT
9/PFS
kHz/kPa
ICC
55
mA
EVALUATION BOARD
The following sections present an example of the signal
conditioning, including frequency conversion, that was
developed as an evaluation tool for the Motorola MPX2000
series pressure sensors. A summary of the information
required to use evaluation board number DEVB160 is
presented as follows.
Description
The evaluation board shown in Figure 1 is designed to
transduce pressure, vacuum or differential pressure into a
single–ended, ground referenced voltage that is then input to
a voltage–to–frequency converter. It nominally provides a 1
kHz output at zero pressure and 10 kHz at full scale pressure.
Zero pressure calibration is made with a trimpot that is located
on the lower half of the left side of the board, while the full scale
output can be calibrated via another trimpot just above the
offset adjust. The board comes with an MPX2100DP sensor
installed, but will accommodate any MPX2000 series sensor.
One additional modification that may be required is that the
gain of the circuit must be increased slightly when using an
MPX2010 sensor. Specifically, the resistor R5 must be
increased from 7.5 kΩ to 12 kΩ.
Circuit Description
The following pin description and circuit operation
corresponds to the schematic shown in Figure 2.
Pin–by–Pin Description
B +:
Input power is supplied at the B+ terminal of connector CN1.
Minimum input voltage is 10 V and maximum is 30 V.
Fout:
A logic–level (5 V) frequency output is supplied at the OUT
terminal (CN1). The nominal signal it provides is 1 kHz at zero
Motorola Sensor Device Data
Typ
PFS
Full Scale Output
Freescale Semiconductor, Inc...
Symbol
pressure and 10 kHz at full scale pressure. Zero pressure
frequency is adjustable and set with R12. Full–scale
frequency is calibrated via R13. This output is designed to be
directly connected to a microcontroller timer system
input–capture channel.
GND:
The ground terminal on connector CN1 is intended for use
as the power supply return and signal common. Test point
terminal TP3 is also connected to ground, for measurement
convenience.
TP1:
Test point 1 is connected to the final frequency output, Fout.
TP2:
Test point 2 is connected to the +5 V regulator output. It can
be used to verify that this supply voltage is within its tolerance.
TP3:
Test point 3 is the additional ground point mentioned above
in the GND description.
TP4:
Test point 4 is connected to the +8 V regulator output. It can
be used to verify that this supply voltage is within its tolerance.
P1, P2:
Pressure and Vacuum ports P1 and P2 protrude from the
sensor on the right side of the board. Pressure port P1 is on
the top (marked side of package) and vacuum port P2, if
present, is on the bottom. When the board is set up with a dual
ported sensor (DP suffix), pressure applied to P1, vacuum
applied to P2 or a differential pressure applied between the
two all produce the same output voltage per kPa of input.
Neither port is labeled. Absolute maximum differential
pressure is 700 kPa.
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3–265
2
3–266
C1
1 µF
1
3
on/off
S1
3
IN
2
1
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R4
1.5 k Ω
3
1
4
2
C2
0.1 µ F
TP4
OFFSET
R12
200 Ω
GROUND
OUT
U2
MC78L08ACP
X1
MPX2100DP
D1
MV57124A
R8
620Ω
–
+
11
U1A
MC33274
1
5
6
–
+
U1B
7
R5
R6
120 Ω 7.5 k Ω
2
3
4
R7
820 Ω
13
12
10
9
–
+
–
+
8
R9
1 kΩ
U1D
14
R10
2 kΩ
R11
C4 2 kΩ
0.1 µF
U1C
Freescale Semiconductor, Inc...
R13
1 kΩ
R3
4.3 k Ω
R2
1 kΩ
C3
0.01 µ F
C6
0.1 µF
1
TP3
+
C5
10 µ F
TANTALUM
FULL–SCALE
VCC
Ct
Ct
VSS
8
7
6
5
OUT
GROUND
2
AD654
IN
1 Fout
2
LogCom
3
4 Rt
+Vin
3
U4
MC78L05ACP
TP1
1
2
3
B+
Fout
GND
CN1
B+
U5
BS107A
R1
240 Ω
TP2
AN1316
Freescale Semiconductor, Inc.
Figure 2. DEVB160 Frequency Output Sensor Evaluation Board
Motorola Sensor Device Data
Freescale Semiconductor, Inc.
AN1316
The following is a table of the components that are assembled on the DEVB160 Frequency Output Sensor Evaluation Board.
Table 2. Parts List
Freescale Semiconductor, Inc...
Designators
Quantity
Description
Manufacturer
Part Number
C1
1
1 µF Capacitor
C2
1
0.1 µF Capacitor
C3
1
0.01 µF Capacitor
C4
1
0.1 µF Capacitor
C5
1
10 µF Cap+
C6
1
0.1 µF Capacitor
CN1
1
.15LS 3 Term
PHX Contact
1727023
D1
1
RED LED
Quality Tech.
MV57124A
R1
1
240 Ω resistor
R2, R9
2
1 kΩ resistor
R3
1
4.3 kΩ resistor
R4
1
1.5 kΩ resistor
R5
1
7.5 kΩ resistor
R6
1
120 Ω resistor
R7
1
820 Ω resistor
R8
1
620 Ω resistor
R10, R11
2
2 kΩ resistor
R12
1
200 Ω Trimpot
Bourns
3386P–1–201
R13
1
1 kΩ Trimpot
Bourns
3386P–1–102
S1
1
SPDT miniature switch
NKK
SS–12SDP2
TP1
1
YELLOW Testpoint
Control Design
TP–104–01–04
TP2
1
BLUE Testpoint
Control Design
TP–104–01–06
TP3
1
BLACK Testpoint
Control Design
TP–104–01–00
TP4
1
GREEN Testpoint
Control Design
TP–104–01–05
U1
1
Quad Op Amp
Motorola
MC33274
U2
1
8 V Regulator
Motorola
MC78L08ACP
U3
1
AD654
Analog Devices
AD654
U4
1
5 V Regulator
Motorola
MC78L05ACP
U5
1
Small–Signal FET
Motorola
BS107A
X1
1
Pressure Sensor
Motorola
MPX2100DP
tantalum
NOTE: All resistors are 1/4 watt, 5% tolerance values. All capacitors are 50 V rated, ±20% tolerance values.
Motorola Sensor Device Data
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Freescale Semiconductor, Inc...
AN1316
Freescale Semiconductor, Inc.
Circuit Operation
The voltage signal conditioning portion of this circuit is a
variation on the classic instrumentation amplifier
configuration. It is capable of providing high differential gain
and good common–mode rejection with very high input
impedance; however, it provides a more user friendly method
of performing the offset/bias point adjustment. It uses four op
amps and several resistors to amplify and level shift the
sensor’s output. Most of the amplification is done in U1A
which is configured as a differential amplifier. Unwanted
current flow through the sensor is prevented by buffer U1B. At
zero pressure the differential voltage from pin 2 to pin 4 on the
sensor has been precision trimmed to essentially zero volts.
The common–mode voltage on each of these nodes is 4 V
(one–half the sensor supply voltage). The zero pressure
output voltage at pin 1 of U1A is then 4.0 V, since any other
voltage would be coupled back to pin 2 via R5 and create a
non–zero bias across U1A’s differential inputs. This 4.0 V zero
pressure DC output voltage is then level translated to the
desired zero pressure offset voltage by U1C and U1D. The
offset voltage is produced by R4 and adjustment trimpot R12.
R7’s value is such that the total source impedance into pin 13
is approximately 1 k. The gain is approximately (R5/R6)(1 +
R11/R10), which is 125 for the values shown in Figure 2. A
gain of 125 is selected to provide a 4 V span for 32 mV of
full–scale sensor output (at a sensor supply voltage of 8 V).
The resulting .5 V to 4.5 V output from U1C is then
converted by the V/F converter to the nominal 1–10 kHz that
has been specified. The AD654 V/F converter receives the
amplified sensor output at pin 8 of op amp U1C. The full–scale
frequency is determined by R3, R13 and C3 according to the
following formula:
F out (full-scale)
+ (10V)(R3V)in R13)C3
For best performance, R3 and R13 should be chosen to
provide 1 mA of drive current at the full–scale voltage
produced at pin 3 of the AD654 (U3). The input stage of the
AD654 is an op–amp; thus, it will work to make the voltage at
pin 3 of U3 equal to the voltage seen at pin 4 of U3 (pins 3 and
4 are the input terminals of the op amp). Since the amplified
sensor output will be 4.5 V at full–scale pressure, R3 + R13
should be approximately equal to 4.5 kΩ to have optimal
linearity performance. Once the total resistance from pin 3 of
U3 to ground is set, the value of C3 will determine the
full–scale frequency output of the V/F. Trimpot R13 should be
sized (relative to R3 value) to provide the desired amount of
full–scale frequency adjustment. The zero–pressure
frequency is adjusted via the offset adjust provided for
calibrating the offset voltage of the signal conditioned sensor
output. For additional information on using this particular V/F
converter, see the applications information provided in the
Analog Devices Data Conversion Products Databook.
The frequency output has its edge transitions “sped” up by
a small–signal FET inverter. This final output is directly
compatible with microprocessor timer inputs, as well as any
3–268
other high–speed CMOS logic. The amplifier portion of this
circuit has been patented by Motorola Inc. and was introduced
on evaluation board DEVB150A. Additional information
pertaining to this circuit and the evaluation board DEVB150A
is contained in Motorola Application Note AN1313.1
TEST/CALIBRATION PROCEDURE
1. Connect a +12 V supply between B+ and GND terminals
on the connector CN1.
2. Connect a frequency counter or scope probe on the Fout
terminal of CN1 or on TP1 with the test instrumentation
ground clipped to TP3 or GND.
3 . Turn the power switch, S1, to the on position. Power
LED, D1, should be illuminated. Verify that the voltage at
TP2 and TP4 (relative to GND or TP3) is 5 V and 8 V,
respectively. While monitoring the frequency output by
whichever means one has chosen, one should see a
50% duty cycle square wave signal.
4. Turn the wiper of the OFFSET adjust trimpot, R12, to the
approximate center of the pot.
5. Apply 100 kPa to pressure port P1 of the MPX2100DP
(topside port on marked side of the package) sensor, X1.
6. Adjust the FULL–SCALE trimpot, R13, until the output
frequency is 10 kHz. If 10 kHz is not within the trim range
of the full–scale adjustment trimpot, tweak the offset
adjust trimpot to obtain 10 kHz (remember, the offset pot
was at an arbitrary midrange setting as per step 4).
7. Apply zero pressure to the pressure port (i.e., both ports
at ambient pressure, no differential pressure applied).
Adjust OFFSET trimpot so frequency output is 1 kHz.
8. Verify that zero pressure and full–scale pressure
(100 kPa) produce 1 and 10 kHz respectively, at Fout
and/or TP1. A second iteration of adjustment on both
full–scale and offset may be necessary to fine tune the
1 – 10 kHz range.
CONCLUSION
Transforming conventional analog voltage sensor outputs
to frequency has great utility for a variety of applications.
Sensing remotely and/or in noisy environments is particularly
challenging for low–level (mV) voltage output sensors such as
the MPX2000 Series pressure sensors. Converting the
MPX2000 sensor output to frequency is relatively easy to
accomplish, while providing the noise immunity required for
accurate pressure sensing. The evaluation board presented
is an excellent tool for either “stand–alone” evaluation of the
MPX2000 Series pressure sensors or as a building block for
system prototyping which can make use of DEVB160 as a
“drop–in” frequency output sensor solution. The output of the
DEVB160 circuit is ideally conditioned for interfacing to MCU
timer inputs that can measure the sensor frequency signal.
REFERENCES
1. Schultz, Warren (Motorola, Inc.), “Sensor Building Block
Evaluation Board,” Motorola Application Note AN1313.
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Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
AN1318
Interfacing Semiconductor Pressure Sensors
to Microcomputers
Prepared by: Warren Schultz
Discrete Applications Engineering
Freescale Semiconductor, Inc...
INTRODUCTION
The most popular silicon pressure sensors are
piezoresistive bridges that produce a differential output
voltage in response to pressure applied to a thin silicon
diaphragm. Output voltage for these sensors is generally 25
to 50 mV full scale. Interface to microcomputers, therefore,
generally involves gaining up the relatively small output
voltage, performing a differential to single ended conversion,
and scaling the analog signal into a range appropriate for
analog to digital conversion. Alternately, the analog pressure
signal can be converted to a frequency modulated 5 V
waveform or 4–20 mA current loop, either of which is relatively
immune to noise on long interconnect lines.
A variety of circuit techniques that address interface design
are presented. Sensing amplifiers, analog to digital
conversion, frequency modulation and 4–20 mA current loops
are considered.
B+
PRESSURE
RC1
RP2
RV1
S+
S–
RP1
RV2
RC2
RETURN
Figure 1. Sensor Equivalent Circuit
PRESSURE SENSOR BASICS
The essence of piezoresistive pressure sensors is the
Wheatstone bridge shown in Figure 1. Bridge resistors RP1,
RP2, RV1 and RV2 are arranged on a thin silicon diaphragm
such that when pressure is applied RP1 and RP2 increase in
value while RV1 and RV2 decrease a similar amount.
Pressure on the diaphragm, therefore, unbalances the bridge
and produces a differential output signal. One of the
fundamental properties of this structure is that the differential
output voltage is directly proportional to bias voltage B+. This
characteristic implies that the accuracy of the pressure
measurement depends directly on the tolerance of the bias
supply. It also provides a convenient means for temperature
compensation. The bridge resistors are silicon resistors that
have positive temperature coefficients. Therefore, when they
are placed in series with zero TC temperature compensation
resistors RC1 and RC2 the amount of voltage applied to the
bridge increases with temperature. This increase in voltage
produces an increase in electrical sensitivity which offsets and
compensates for the negative temperature coefficient
associated with piezoresistance.
Since RC1 and RC2 are approximately equal, the output
voltage common mode is very nearly fixed at 1/2 B+. In a
typical MPX2100 sensor, the bridge resistors are nominally
425 ohms; RC1 and RC2 are nominally 680 ohms. With these
values and 10 V applied to B+, a delta R of 1.8 ohms at full
scale pressure produces 40 mV of differential output voltage.
INSTRUMENTATION AMPLIFIER INTERFACES
Instrumentation amplifiers are by far the most common
interface circuits that are used with pressure sensors. An
example of an inexpensive instrumentation amplifier based
interface circuit is shown in Figure 2. It uses an MC33274 quad
operational amplifier and several resistors that are configured
as a classic instrumentation amplifier with one important
exception. In an instrumentation amplifier resistor R3 is
normally returned to ground. Returning R3 to ground sets the
output voltage for zero differential input to 0 V DC. For
microcomputer interface a positive offset voltage on the order
of 0.3 to 0.8 V is generally desired. Therefore, R3 is connected
to pin 14 of U1D which supplies a buffered offset voltage that
is derived from the wiper of R6. This voltage establishes a DC
output for zero differential input. The translation is one to one.
Within the tolerances of the circuit, whatever voltage appears
at the wiper of R6 will also appear as the zero pressure DC
offset voltage at the output.
With R10 at 240 ohms, gain is set for a nominal value of 125.
This provides a 4 V span for 32 mV of full scale sensor output.
Setting the offset voltage to .75 V results in a 0.75 V to 4.75 V
output that is directly compatible with microprocessor A/D
inputs. Over a zero to 50° C temperature range, combined
accuracy for an MPX2000 series sensor and this interface is
on the order of ± 10%.
REV 1
Motorola Sensor Device Data
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Freescale Semiconductor, Inc.
AN1318
B+
U2
3 MC78L08ACP
I
O
1
G
R7
7.5 k
2
C1
1 µF
C2
0.1 µF
5
+
6 –
4
ZERO
7
U1B
MC33274
R6
1k
12
13
R4
1k
Freescale Semiconductor, Inc...
XDCR1
MPX2000 SERIES
PRESSURE SENSOR
3
4
2
1
10
9
C3 .001 µF
R10
240*
2
3
R9
15 k
U1A
MC33274
1
–
+
11
14
U1D
MC33274
R3 1 k
R8 15 k
GND
+
–
U1C
MC33274
8
+
–
R5
R2
1k
1k
OUTPUT
* NOTE: FOR MPX2010, R10 = 150 OHMS
Figure 2. Instrumentation Amplifier Interface
For applications requiring greater precision a fully
integrated instrument amplifier such as an LTC1100CN8 gives
better results. In Figure 3 one of these amplifiers is used to
provide a gain of 100, as well as differential to single ended
conversion. Zero offset is provided by dividing down the
precision reference to 0.5 V and buffering with U2B. This
voltage is fed into the LTC1100CN8’s ground pin which is
equivalent to returning R3 to pin 14 of U1D in Figure 2. An
additional non–inverting gain stage consisting of U2A, R1 and
R2 is used to scale the sensor’s full scale span to 4 V. R2 is
also returned to the buffered .5 V to maintain the 0.5 V zero
offset that was established in the instrumentation amplifier.
Output voltage range is therefore 0.5 to 4.5 V.
Both of these instrumentation amplifier circuits do their
intended job with a relatively straightforward tradeoff between
cost and performance. The circuit of Figure 2 has the usual
cumulative tolerance problem that is associated with
instrumentation amplifiers that have discrete resistors, but it
has a relatively low cost. The integrated instrumentation
amplifier in Figure 3 solves this problem with precision
trimmed film resistors and also provides superior input offset
performance. Component cost, however, is significantly
higher.
3–270
SENSOR SPECIFIC INTERFACE AMPLIFIER
A low cost interface designed specifically for pressure
sensors improves upon the instrumentation amplifier in Figure
2. Shown in Figure 4, it uses one quad op amp and several
resistors to amplify and level shift the sensor’s output. Most of
the amplification is done in U1A which is configured as a
differential amplifier. It is isolated from the sensor’s positive
output by U1B. The purpose of U1B is to prevent feedback
current that flows through R5 and R6 from flowing into the
sensor. At zero pressure the voltage from pin 2 to pin 4 on the
sensor is 0 V. For example, let’s say that the common mode
voltage on these pins is 4.0 V. The zero pressure output
voltage at pin 1 of U1A is then 4.0 V, since any other voltage
would be coupled back to pin 2 via R6 and create a non–zero
bias across U1A’s differential inputs. This 4.0 V zero pressure
DC output voltage is then level translated to the desired zero
pressure offset voltage (VOFFSET) by U1C and U1D.
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Freescale Semiconductor, Inc.
AN1318
B+
U1
1
2
3
4
8
7
6
5
NC
NC
VIN
NC
VT
OUT
GND TRM
C3
0.01 µF
MC1404
U1
C1
1µF
6
2 XDCR1
MPX2000 SERIES
PRESSURE SENSOR 3
3
C2
0.1 µF
1
4
+
5
7
3
–
4
2
1
LTC1100CN8
+
–
8
U2A 1
OUTPUT
MC34072
Freescale Semiconductor, Inc...
4
R3
19.1 k 1%
U2B
5
6
R4
1 k 1%
+
–
R2
10 k 1%
7
R1
6.04 k 1%
MC34072
Figure 3. Precision Instrument Amplifier Interface
B+
3
I
O
U2
MC78L08ACP
1
G
2
C2
0.1 µF
C1
1 µF
3
4
1
+
2 –
U1A
MC33274
U1C
MC33274
10
8
+
9 –
R6 7.5 k
3
XDCR1
MPX2000 SERIES
PRESSURE
4
SENSOR
GND
R8
1.5 k
2
1
R1 2 k
R5
120*
R2 2 k
U1B
MC33274
7
–
5 +
11
6
R9
200
OUTPUT
12
+
13 –
R3
820
14
U1D
MC33274
R4 1 k
ZERO
CAL.
* NOTE: FOR MPX2010, R5 = 75 OHMS
Figure 4. Sensor Specific Interface Circuit
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3–271
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AN1318
To see how the level translation works, let’s look at the
simplified schematic in Figure 5. Again assuming a common
mode voltage of 4.0 V, the voltage applied to pin 12 of U1D is
4.0 V, implying that pin 13 is also at 4.0 V. This leaves 4.0 V
– VOFFSET across R3, which is 3.5 V if VOFFSET is set to 0.5
V. Since no current flows into pin 13, the same current flows
through both R3 and R4. With both of these resistors set to the
same value, they have the same voltage drop, implying a 3.5
V drop across R4. Adding the voltages (0.5 + 3.5 + 3.5) yields
7.5 V at pin 14 of U1D. Similarly 4.0 V at pin 10 of U1C implies
4.0 V at pin 9, and the drop across R2 is 7.5 V – 4.0 V = 3.5
V. Again 3.5 V across R2 implies an equal drop across R1, and
the voltage at pin 8 is 4.0 V – 3.5 V = .5 V. For this DC output
voltage to be independent of the sensor’s common mode
voltage it is necessary to satisfy the condition that R4/R3 =
R2/R1. In Figure 4, VOFFSET is produced by R8 and
adjustment pot R9. R3’s value is adjusted such that the total
source impedance into pin 13 is approximately 1 k.
B+
3
4
1
+
2 –
U1A
MC33274
Freescale Semiconductor, Inc...
+8
3
XDCR1
MPX2000 SERIES
PRESSURE
SENSOR
4
R6 7.5 k
2
1
U1C
MC33274
10
8
+
9 –
R1 2 k
R5
120*
R2 2 k
U1B
MC33274
7
–
5 +
11
6
GND
OUTPUT
12
+
13 –
R3
1k
14
U1D
MC33274
R4 1 k
VOFFSET
*NOTE: FOR MPX2010, R5 = 75 OHMS
Figure 5. Simplified Sensor Specific Interface
Gain is approximately (R6/R5)(R1/R2+1), which is 125 for
the values shown in Figure 4. A gain of 125 is selected to
provide a 4 V span for the 32 mV of full scale sensor output that
is obtained with 8 V B+.
The resulting 0.5 V to 4.5 V output from U1C is preferable
to the 0.75 to 4.75 V range developed by the instrument
amplifier configuration in Figure 2. It also uses fewer parts.
This circuit does not have the instrument amplifier’s
propensity for oscillation and therefore does not require
compensation capacitor C3 that is shown in Figure 2. It also
requires one less resistor, which in addition to reducing
component count also reduces accumulated tolerances due
to resistor variations.
This circuit as well as the instrumentation amplifier interfaces
in Figures 2 and 3 is designed for direct connection to a
3–272
microcomputer A/D input. Using the MC68HC11 as an
example, the interface circuit output is connected to any of the
E ports, such as port E0 as shown in Figure 6. To get maximum
accuracy from the A/D conversion, VREFH is tied to 4.85 V and
VREFL is tied to 0.30 V by dividing down a 5 V reference with
1% resistors.
SINGLE SLOPE A/D CONVERTER
The 8 bit A/D converters that are commonly available on
chip in microcomputers are usually well suited to pressure
sensing applications. In applications that require more than 8
bits, the circuit in Figure 7 extends resolution to 11 bits with an
external analog–to–digital converter. It also provides an
interface to digital systems that do not have an internal A/D
function.
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+5 V
B+
15.0 OHMS
1%
X4.85 V
VS
MPX2000
SERIES
PRESSURE
SENSOR
453 OHMS
1%
RC1
X.302 V
RV1
RP2
S+
S–
RV2
VREFL
MC68HC11
B+
+
0
INTERFACE OUTPUT
AMPLIFIER
RP1
VREFH
30.1 OHMS
1%
BIAS
1
2
—
3
4
GND
Freescale Semiconductor, Inc...
AN1318
PORT E
5
RC2
6
7
GND
VSS
RETURN
Figure 6. Application Example
Beginning with the ramp generator, a timing ramp is
generated with current source U5 and capacitor C3.
Initialization is provided by Q1 which sets the voltage on C3
at approximately ground. With the values shown, 470 µA
flowing into 0.47 µF provide approximately a 5 msec ramp time
from zero to 5 V. Assuming zero pressure on the sensor, inputs
to both comparators U2A and U2B are at the same voltage.
Therefore, as the ramp voltage sweeps from zero to 5 V, both
PA0 and PA1 will go low at the same time when the ramp
voltage exceeds the common mode voltage. The processor
counts the number of clock cycles between the time that PA0
and PA1 go low, reading zero for zero pressure.
In this circuit, U4A and U4B form the front end of an
instrument amplifier. They differentially amplify the sensor’s
output. The resulting amplified differential signal is then
sampled and held in U1 and U3. The sample and hold function
is performed in order to keep input data constant during the
conversion process. The stabilized signals coming out of U1
and U3 feed a higher output voltage to U2A than U2B,
assuming that pressure is applied to the sensor. Therefore,
the ramp will trip U2B before U2A is tripped, creating a time
difference between PA0 going low and PA1 going low. The
processor reads the number of clock cycles between these
two events. This number is then linearly scaled with software
to represent the amplified output voltage, accomplishing the
analog to digital conversion.
When the ramp reaches the reference voltage established
by R9 and R10, comparator U2C is tripped, and a reset
command is generated. To accomplish reset, Q1 is turned on
Motorola Sensor Device Data
with an output from PA7, and the sample and hold circuits are
delatched with an output from PB1. Resolution is limited by
clock frequency and ramp linearity. With the ramp generator
shown in Figure 7 and a clock frequency of 2 MHz; resolution
is 11 bits.
From a software point of view, the A/D conversion consists
of latching the sample and hold, reading the value of the
microcomputer’s free running counter, turning off Q1, and
waiting for the three comparator outputs to change state from
logic 1 to logic 0. The analog input voltage is determined by
counting, in 0.5 µsec steps, the number of clock cycles
between PA0 and PA1 going low.
LONG DISTANCE INTERFACES
In applications where there is a significant distance between
the sensor and microcomputer, two types of interfaces are
typically used. They are frequency output and 4–20 mA loops.
In the frequency output topology, pressure is converted into a
zero to 5 V digital signal whose frequency varies linearly with
pressure. A minimum frequency corresponds to zero pressure
and above this, frequency output is determined by a Hz/unit
pressure scaling factor. If minimizing the number of wires to a
remote sensor is the most important design consideration,
4–20 mA current loops are the topology of choice. These loops
utilize power and ground as the 4–20 mA signal line and
therefore require only two wires to the sensor. In this topology
4 mA of total current drain from the sensor corresponds to zero
pressure, and 20 mA to full scale.
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3–273
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More Information On This Product,
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+5
+10
2
1
3
4
NOTE:
UNLESS OTHERWISE SPECIFIED
ALL RESISTORS ARE 1% METAL FILM
XDCR1
MPX2000 SERIES
PRESSURE SENSOR
U5
LM334Z-3
1
C2 22 pF
C1 22 pF
R2 402 k
U4A
MC33078
4
1.5 k 5%
R6
11
U4B
MC33078
7
R3 402 k
6
5 –
R5
120*
2 –
3
R4
147
1N914
D1
7
6
4
8
3
7
1
6
4
+8.5 –8.5
8
3
1
R8
22 k 5%
C4
0.01 µ F
POLYPROP
LF398A
5
U3
R7
22 k 5%
C5
0.01 µ F
POLYPROP
LF398A
5
U1
+8.5 –8.5
C3
0.47 µ F
10
11
7
6
4
5
9
8
–
+
4.7
5%
–
+
2
1
13
LM139A
U2D
LM139A
U2B
2N7000
Q1
14
LM139A
U2A
R5
LM139A
U2C
Freescale Semiconductor, Inc...
+
–
+
+
–
3–274
+
C7
0.1 µ F
+5
R10
9.09 k
R9
1k
PA0
PB1
PA1
U7
MC68HC11E9FN
PA7
PA2
AN1318
Freescale Semiconductor, Inc.
Figure 7. Single Slope A/D Converter
Motorola Sensor Device Data
Motorola Sensor Device Data
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Information On This Product,
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C1
1 µF
G
I
2
3
O
200
R5
1.5 k
4
3
1
2
XDCR1
MPX2000 SERIES
PRESSURE SENSOR
ZERO
CAL.
R3
1
U1
MC78L08ACP
* NOTE: FOR MPX2010, R8 = 75 OHMS
GND
B+
R4 7.5 k
11
U2B
MC33274
6 –
7
5 +
R8
120*
4
U2A
MC33274
+
2 –
3
R2
820
10 –
9 +
U2C
MC33274
R1 1 k
8
R7 2 k
U2D
12 MC33274
14
13 +–
R6 2 k
C2
0.1µ F
RT
VIN
+
V
S
8
R12
1k
FULL SCALE CAL.
R11
4.3 k
3
4
U3
AD654
5
–
V
S
Freescale Semiconductor, Inc...
0
5V
C
T
6
C
O
M
2
FOUT
C
T
7
1
2
G
3
NOMINAL OUTPUT:
1 kHz @ ZERO PRESSURE
10 kHz @ FULL SCALE
0.01µ F
C3
R9
1k
I
O
1
R10
240
OUTPUT
C4
0.1 µ F
Q1
BS107A
U4
MC78L05ACP
Freescale Semiconductor, Inc.
AN1318
Figure 8. Frequency Output Pressure Sensor
3–275
Freescale Semiconductor, Inc.
AN1318
a twisted pair line is relatively easy. Where very long distances
are involved, the primary disadvantage is that 3 wires (VCC,
ground and an output line) are routed to the sensor.
A 4–20 mA loop reduces the number of wires to two. Its
output is embedded in the VCC and ground lines as an active
current source. A straightforward way to apply this technique
to pressure sensing is shown in Figure 9. In this figure an
MPX7000 series high impedance pressure sensor is mated to
an XTR101 4–20 mA two–wire transmitter. It is set up to pull
4 mA from its power line at zero pressure and 20 mA at full
scale. At the receiving end a 240 ohm resistor referenced to
signal ground will provide a 0.96 to 4.8 V signal that is suitable
for microcomputer A/D inputs.
A relatively straightforward circuit for converting pressure to
frequency is shown in Figure 8. It consists of three basic parts.
The interface amplifier is the same circuit that was described
in Figure 4. Its 0.5 to 4.5 V output is fed directly into an AD654
voltage–to–frequency converter. On the AD654, C3 sets
nominal output frequency. Zero pressure output is calibrated
to 1 kHz by adjusting the zero pressure input voltage with R3.
Full scale adjustments are made with R12 which sets the full
scale frequency to 10 kHz. The output of the AD654 is then fed
into a buffer consisting of Q1 and R10. The buffer is used to
clean up the edges and level translate the output to 5 V.
Advantages of this approach are that the frequency output is
easily read by a microcomputer’s timer and transmission over
Freescale Semiconductor, Inc...
2 mA
4–20 mA OUTPUT
XDCR1
MPX7000
SERIES
SENSOR
3
2
R3
30
5
6
1
4
4
R5
100
3
1
0
1
1
D1
1N4002
Q1
MPSA06
C1
0.01 µF
+
U1
XTR101
–
12
+
R1
750
1/2 W
8
24 V
.96 – 4.8
V
PLOOP
240
1 2 1 7 1 9
4 3
D2
1N4565A
6.4 V @ .5 mA
SPAN
–
R6
100 k
R2
1k
R4
1M
RETURN
OFFSET
Figure 9. 4–20 mA Pressure Transducer
Bias for the sensor is provided by two 1 mA current sources
(pins 10 and 11) that are tied in parallel and run into a 1N4565A
6.4 V temperature compensated zener reference. The
sensor’s differential output is fed directly into XTR101’s
inverting and non–inverting inputs. Zero pressure offset is
calibrated to 4 mA with R6. Biased with 6.4 V, the sensor’s full
scale output is 24.8 mV. Given this input R3 + R5 nominally
total 64 ohms to produce the 16 mA span required for 20 mA
full scale. Calibration is set with R5.
The XTR101 requires that the differential input voltage at pins
3–276
3 and 4 has a common mode voltage between 4 and 6 V. The
sensor’s common mode voltage is one half its supply voltage
or 3.2 V. R2 boosts this common mode voltage by
1 k S 2 mA or 2 V, establishing a common mode voltage for the
transmitter’s input of 5.2 V. To allow operation over a 12 to 40
V range, dissipation is off–loaded from the IC by boosting the
output with Q1 and R1. D1 is also included for protection. It
prohibits reverse polarity from causing damage. Advantages of
this topology include simplicity and, of course, the two wire
interface.
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Motorola Sensor Device Data
+5
Motorola Sensor Device Data
J1
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J2
R2
10 k
R3
10 k
3
C1
22 pF
XDCR1
MPX5100
C2
22 pF
U2
R1
10 M
MC34064P-5
4.7 k
R4
2
1
Y1
4 MHz
OSC2
OSC1
PD6
PD7
RESET
PD5
IRQ
VPP6
PD1
PD2
PD3
PD4
VDD
PD0
TCAP2
TCAP1
D/A
R6
15 %
VSS
U1
RDI
TDO
VRL
MC68HC705B5FN
VRH
R5
453 %
PA0
PA2
PA1
PA7
PA6
PA5
PA4
PA3
PB2
PB1
PB7
PB6
PB5
PB4
PB3
PC0
PC2
PC1
PC7
PC6
PC5
PC4
PC3
R7
30.1 %
Freescale Semiconductor, Inc...
40
22
23
17
18
19
20
21
16
26
27
13
14
15
24
25
12
31
32
9
10
11
29
30
1
2
3
4
5
6
7
28
33
34
35
36
37
38
39
8
LIQUID
CRYSTAL
DISPLAY
IEEE LCD 5657
OR EQUIVALENT
Freescale Semiconductor, Inc.
AN1318
Figure 10. MPX5100 LCD Pressure Gauge
3–277
AN1318
Freescale Semiconductor, Inc.
Freescale Semiconductor, Inc...
DIRECT INTERFACE
WITH INTEGRATED SENSORS
The simplest interface is achieved with an integrated sensor
and a microcomputer that has an on–chip A/D converter.
Figure 10 shows an LCD pressure gauge that is made with an
MPX5100 integrated sensor and MC68HC05 microcomputer.
Although the total schematic is reasonably complicated, the
interface between the sensor and the micro is a single wire.
The MPX5100 has an internal amplifier that outputs a 0.5 to
4.5 V signal that inputs directly to A/D port PD5 on the HC05.
The software in this system is written such that the
processor assumes zero pressure at power up, reads the
sensor’s output voltage, and stores this value as zero
pressure offset. Full scale span is adjustable with jumpers J1
and J2. For this particular system the software is written such
that with J1 out and J2 in, span is decreased by 1.5%. Similarly
with J1 in and J2 out, span is increased by 1.5%. Given the ±
2.5% full scale spec on the sensor, these jumpers allow
calibration to ± 1% without the use of pots.
MIX AND MATCH
The circuits that have been described so far are intended to
be used as functional blocks. They may be combined in a
variety of ways to meet the particular needs of an application.
For example, the Frequency Output Pressure Sensor in
Figure 8 uses the sensor interface circuit described in Figure
4 to provide an input to the voltage–to–frequency converter.
Alternately, an MPX5100 could be directly connected to pin 4
of the AD654 or the output of Figure 3’s Precision
Instrumentation Amplifier Interface could by substituted in the
same way. Similarly, the Pressure Gauge described in Figure
10 could be constructed with any of the interfaces that have
been described.
3–278
CONCLUSION
The circuits that have been shown here are intended to
make interfacing semiconductor pressure sensors to digital
systems easier. They provide cost effective and relatively
simple ways of interfacing sensors to microcomputers. The
seven different circuits contain many tradeoffs that can be
matched to the needs of individual applications. When
considering these tradeoffs it is important to throw software
into the equation. Techniques such as automatic zero
pressure calibration can allow one of the inexpensive analog
interfaces to provide performance that could otherwise only be
obtained with a more costly precision interface.
REFERENCES
1. Baum, Jeff, “Frequency Output Conversion for
MPX2000 Series Pressure Sensors,” Motorola Application Note AN1316/D.
2. Lucas, William, “An Evaluation System for Direct Interface of the MPX5100 Pressure Sensor with a Microprocessor,” Motorola Application Note AN1305.
3. Lucas, William, “An Evaluation System for Interfacing the
MPX2000 Series Pressure Sensors to a Microprocessor,” Motorola Application Note AN1315.
4. Schultz, Warren, “Compensated Sensor Bar Graph
Pressure Gauge,” Motorola Application Note AN1309.
5. Schultz, Warren, “Interfaced Sensor Evaluation Board,”
Motorola Application Note AN1312.
6. Schultz, Warren, “Sensor Building Block Evaluation
Board,” Motorola Application Note AN1313.
7. Williams, Denise, “A Simple 4–20 mA Pressure Transducer Evaluation Board,” Motorola Application Note
AN1303.
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Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
Applying Semiconductor Sensors to
Bar Graph Pressure Gauges
AN1322
Prepared by: Warren Schultz
Discrete Applications Engineering
Freescale Semiconductor, Inc...
INTRODUCTION
Bar Graph displays are noted for their ability to very quickly
convey a relative sense of how much of something is present.
They are particularly useful in process monitoring applications
where quick communication of a relative value is more
important than providing specific data.
Designing bar graph pressure gauges based upon
semiconductor pressure sensors is relatively straightforward.
The sensors can be interfaced to bar graph display drive IC’s,
microcomputers and MC33161 voltage monitors. Design
examples for all three types are included.
BAR GRAPH DISPLAY DRIVER
Interfacing semiconductor pressure sensors to a bar graph
display IC such as an LM3914 is very similar to microcomputer
interface. The same 0.5 to 4.5 V analog signal that a
microcomputer’s A/D converter wants to see is also quite
suitable for driving an LM3914. In Figure 1, this interface is
provided by dual op amp U2 and several resistors.
The op amp interface amplifies and level shifts the sensor’s
output. To see how this amplifier works, simplify it by
grounding the output of voltage divider R3, R5. If the common
mode voltage at pins 2 and 4 of the sensor is 4.0 V, then pin
2 of U2A and pin 6 of U2B are also at 4.0 V. This puts 4.0 V
across R6. Assuming that the current in R4 is equal to the
current in R6, 323 µA • 100 ohms produces a 32 mV drop
across R4 which adds to the 4.0 V at pin 2. The output voltage
at pin 1 of U2A is, therefore, 4.032 V. This puts 4.032 – 4.0 V
across R2, producing 43 µA. The same current flowing
through R1 again produces a voltage drop of 4.0 V, which sets
the output at zero. Substituting a divider output greater than
zero into this calculation reveals that the zero pressure output
voltage is equal to the output voltage of divider R3, R5. For this
DC output voltage to be independent of the sensor’s common
mode voltage, it is necessary to satisfy the condition that
R1/R2 = R6/R4.
Gain can be determined by assuming a differential output
at the sensor and going through the same calculation. To do
this assume 100 mV of differential output, which puts pin 2 of
U2A at 3.95 V, and pin 6 of U2B at 4.05 V. Therefore, 3.95 V is
applied to R6, generating 319 µA. This current flowing through R4
produces 31.9 mV, placing pin 1 of U2A at 3950 mV + 31.9 mV
= 3982 mV. The voltage across R2 is then 4050 mV – 3982 mV
= 68 mV, which produces a current of 91 µA that flows into R1.
The output voltage is then 4.05 V + (91 µA • 93.1k) = 12.5 V.
Dividing 12.5 V by the 100 mV input yields a gain of 125, which
provides a 4.0 V span for 32 mV of full scale sensor output.
Setting divider R3, R5 at 0.5 V results in a 0.5 V to 4.5 V
output that is easily tied to an LM3914. The block diagram that
appears in Figure 2 shows the LM3914’s internal architecture.
Since the lower resistor in the input comparator chain is
pinned out at RLO, it is a simple matter to tie this pin to a voltage
that is approximately equal to the interface circuit’s 0.5 V
zero pressure output voltage. Returning to Figure 1, this is
accomplished by using the zero pressure offset voltage that
is generated at the output of divider R3, R5.
Again looking at Figure 1, full scale is set by adjusting the
upper comparator’s reference voltage to match the sensor’s
output at full pressure. An internal regulator on the LM3914
sets this voltage with the aid of resistors R7, R9, and
adjustment pot R8.
Eight volt regulated power is supplied by an MC78L08. The
LED’s are powered directly from LM3914 outputs, which are
set up as current sources. Output current to each LED is
approximately 10 times the reference current that flows from
pin 7 through R7, R8, and R9 to ground. In this design it is
nominally (4.5 V/4.9 k)10 = 9.2 mA.
Over a zero to 50°C temperature range combined accuracy
for the sensor, interface, and driver IC are ±10%. Given a 10
segment display total accuracy for the bar graph readout is
approximately ± (10 kPa +10%).
This circuit can be simplified by substituting an MPX5100
integrated sensor for the MPX2100 and the op amp interface.
The resulting schematic is shown in Figure 3. In this case zero
reference for the bar graph is provided by dividing down the
5 V regulator with R4, R1 and adjustment pot R6. The voltage
at the wiper of R6 is adjusted to match the sensor’s zero
pressure offset voltage. It is connected to RLO to zero the bar
graph.
REV 1
Motorola Sensor Device Data
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3–279
Freescale Semiconductor, Inc.
AN1322
B+
D1
D2
D3
D4
D5
D6
D7
D8
D9
D10
C2
1 µF
D1-D10
MV57164
BAR
GRAPH
C2
0.1µF
U3
3
U1
I
MC78L08ACP
O
1
5
G
Freescale Semiconductor, Inc...
XDCR1
MPX2000
SERIES
1 SENSOR
3
2
6
2
4
GND
1
2
3
4
5
6
7
8
9
R3
1.5 k
1%
8
+
–
7
U2B
R1
93.1 k 1% MC3327
2
C3 0.001 µF
R7
1.2 k
R6
3
+
2
–
18
17
16
15
14
13
12
11
10
LM3914N
R2
750
1%
R9
2.7 k
4
12.4 k
1%
R5
100
1%
FOR MPX2010 SENSORS:
R1 = 150 k
R4 = 61.9 OHMS
R4
Figure 1. Compensated Sensor Bar Graph
Pressure Gauge
100 1%
COMPARATOR
LM391 1 of 10
10
–
4
+
6
REF
OUT
1k
–
+
11
1k
–
+
12
1k
–
+
13
1k
–
+
14
–
+
15
+–
16
REFERENCE 1 k
7 + VOLTAGE
SOURCE
1.25 V
1k
THIS LOAD
DETERMINES
LED
BRIGHTNESS
LED
LED
LED
LED
LED
LED
LED
LED
LED
R8
1k
U2A
MC33272
RHI
LED
GND
B+
RLO
SIG
RHI
REF
ADJ
MOD
–
LED
V+
17
REF
ADJ
8
1k
–
+
1k
–
+
1k
–
+
FROM
PIN 11
18
V+
RLO
3
1k
4
–
5 20 k
SIG
IN
BUFFER
+
V+
1
9
MODE
SELECT
AMPLIFIER
2
V–
CONTROLS
TYPE OF
DISPLAY, BAR
OR SINGLE
LED
Figure 2. LM3914 Block Diagram
3–280
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+12 V
D1
D2
D3
D4
AN1322
D5
D6
D7
D8
D9
D10
C2
1 µF
U1
1
2
3
4
5
6
7
8
9
C1
0.1 µF
U3
3
I
1
O
MC78L05ACP
Freescale Semiconductor, Inc...
G
3
2
R4
1.3 k
GND
1
U2
MPX5100
R2
1.2 k
2
R5
1k
ZERO CAL.
R6
100
LED
GND
B+
RLO
SIG
RHI
REF
ADJ
MOD
LED
LED
LED
LED
LED
LED
LED
LED
LED
18
17
16
15
14
13
12
11
10
LM3914
FULL SCALE CAL.
R3
2.7 k
R1
100
Figure 3. MPX5100 Bar Graph Pressure Gauge
+5
D/A
VRH
TCAP1
TCAP2
VDD
PD0
PD1
PD2
PD3
PD4
VPP6
IRQ
PD5
3
D2
MV53214A
MV54124A
D3
D4
D5
VRL
MV54124A
MV54124A
MV57124A
PC0
I1
MDC4510A
PC1
1
XDCR1
MPX5100
I2
MDC4510A
U1
MC68HC705B5FN
2
R3
4.7 k
D1
PC2
I3
MDC4510A
U2
R2
10 k
MC34064P-5
R1
10 k
J2
PC3
I4
MDC4510A
PD6
PD7
C1
22 pF
J1
RESET
Y1
4 MHz
OSC1
PC4
R4
10 M
C2
22 pF
Motorola Sensor Device Data
OSC2
VSS
I5
MDC4510A
RDI
TDO
Figure 4. Microcomputer Bar Graph Pressure Gauge
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3–281
Freescale Semiconductor, Inc.
AN1322
B+
1
I2
MDC4010A
1
I3
MDC4010A
D6
MV53124A
LOW
D4
2
MV54124A
0k
D5
MV57124A
HIGH
C1
0.1 µF
2
C2
0.1 µF
U1 3
I
O
1
XDCR1
MPX2000
SERIES
SENSOR
G
MC78L08ACP 2
3
GND
5
8
+
6 –
R7
7.5 k
7
D1
1N914
Freescale Semiconductor, Inc...
R1 93.1 k 1%
R3
6.65 k
1%
R5
1.33 k
1%
4
R6
11.3 k
1%
U2A
3 MC33272
+
1
2
–
4
R2
750
1%
U3
R8
10 k
LOW
R9
10 k
HI
R4
100
1%
R10
2.7 k
1
7
2
D2
1N914
C3 0.001 µF
1
I1
MDC4510A
3
U2B
MC33272
2
1
R11
2.7 k
VREF
1
2
3
4
REF
IN1
IN2
GND
VCC
MODE
OUT1
OUT2
8
7
6
5
MC33161
Figure 5. An Inexpensive 3–Segment
Processor Monitor
2.54 V
REFERENCE
VCC
8
MODE SELECT
–
+
OUT1
6
2.8 V
2
INPUT1
+
–
1.27 V
–
+
OUT2
5
0.6 V
3
INPUT2
+
–
1.27 V
GND
4
3–282
Figure 6. MC33161 Block Diagram
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Freescale Semiconductor, Inc...
MICROCOMPUTER BAR GRAPH
Microcomputers with internal A/D converters such as an
MC68HC05B5 lend themselves to easily creating bar graphs.
Using the A/D converter to measure the sensor’s analog
output voltage and output ports to individually switch LED’s
makes a relatively straightforward pressure gauge. This type
of design is facilitated by a new MDC4510A gated current sink.
The MDC4510A takes one of the processor’s logic outputs
and switches 10 mA to an LED. One advantage of this
approach is that it is very flexible regarding the number of
segments that are used, and has the availability through
software to independently adjust scaling factors for each
segment. This approach is particularly useful for process
monitoring in systems where a microprocessor is already in
place.
Figure 4 shows a direct connection from an MPX5100
sensor to the microcomputer. Similar to the previous example,
an MPX2000 series sensor with the op amp interface that is
shown in Figure 1 can be substituted for the MPX5100. In this
case the op amp interface’s output at pin 7 ties to port PD5,
and its supply needs to come from a source greater than
6.5 V.
PROCESS MONITOR
For applications where an inexpensive HIGH-LOW-OK
process monitor is required, the circuit in Figure 5 does a good
job. It uses an MC33161 Universal Voltage Monitor and the
same analog interface previously described to indicate high,
low or in-range pressure.
A block diagram of the MC33161 is illustrated in Figure 6.
By tying pin 1 to pin 7 it is set up as a window detector.
Whenever input 1 exceeds 1.27 V, two logic ones are placed
at the inputs of its exclusive OR gate, turning off output 1.
Therefore this output is on unless the lower threshold is
exceeded. When 1.27 V is exceeded on input 2, just the
opposite occurs. A single logic one appears at its exclusive
OR gate, turning on output 2. These two outputs drive LED’s
through MDC4010A 10 mA current sources to indicate low
pressure and high pressure.
Returning to Figure 5, an in-range indication is developed
by turning on current source I1 whenever both the high and
low outputs are off. This function is accomplished with a
discrete gate made from D1, D2 and R7. Its output feeds the
Motorola Sensor Device Data
AN1322
input of switched current source I1, turning it on with R7 when
neither D1 nor D2 is forward biased.
Thresholds are set independently with R8 and R9. They
sample the same 4.0 V full scale span that is used in the other
examples. However, zero pressure offset is targeted for 1.3 V.
This voltage was chosen to approximate the 1.27 V reference
at both inputs, which avoids throwing away the sensor’s
analog output signal to overcome the MC33161’s input
threshold. In addition, R10 and R11 are selected such that at
full scale output, ie., 5.3 V on pin 7, the low side of the pots is
nominally at 1.1 V. This keeps the minimum input just below
the comparator thresholds of 1.27 V, and maximizes the
resolution available from adjustment pots R8 and R9. When
level adjustment is not desired, R8 – R11 can be replaced by
a simpler string of three fixed resistors.
CONCLUSION
The circuits that have been shown here are intended to
make simple, practical and cost effective bar graph pressure
gauges. Their application involves a variety of trade-offs that
can be matched to the needs of individual applications. In
general, the most important trade-offs are the number of
segments required and processor utilization. If the system in
which the bar graph is used already has a microprocessor with
unused A/D channels and I/O ports, tying MDC4510A current
sources to the unused output ports is a very cost effective
solution. On a stand-alone basis, the MC33161 based
process monitor is the most cost effective where only 2 or 3
segments are required. Applications that require a larger
number of segments are generally best served by one of the
circuits that uses a dedicated bar graph display.
REFERENCES
1. Alberkrack, Jade, & Barrow, Stephen; “Power Supply
Monitor IC Fills Voltage Sensing Roles,” Power Conversion & Intelligent Motion, October 1991.
2. Lucas, William, “An Evaluation System for Direct Interface of the MPX5100 Pressure Sensor with a Microprocessor,” Motorola Application Note AN1305.
3. Schultz, Warren, “Integrated Sensor Simplifies Bar
Graph Pressure Gauge,” Motorola Application Note
AN1304.
4. Schultz, Warren, “Compensated Sensor Bar Graph
Pressure Gauge,” Motorola Application Note AN1309.
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MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
AN1325
Amplifiers for Semiconductor Pressure Sensors
Prepared by: Warren Schultz
Discrete Applications Engineering
Freescale Semiconductor, Inc...
INTRODUCTION
Amplifiers for interfacing Semiconductor Pressure Sensors
to electronic systems have historically been based upon
classic instrumentation amplifier designs. Instrumentation
amplifiers have been widely used because they are well
understood standard building blocks that also work
reasonably well.
For the specific job of interfacing
Semiconductor Pressure Sensors to today’s mostly digital
systems, other circuits can do a better job. This application
note presents an evolution of amplifier design that begins with
a classic instrumentation amplifier and ends with a simpler
circuit that is better suited to sensor interface.
INTERFACE AMPLIFIER REQUIREMENTS
Design requirements for interface amplifiers are
determined by the sensor’s output characteristics, and the
zero to 5 V input range that is acceptable to microcomputer
A/D converters. Since the sensor’s full scale output is typically
tens of millivolts, the most obvious requirement is gain. Gains
from 100 to 250 are generally needed, depending upon bias
voltage applied to the sensor and maximum pressure to be
measured. A differential to single–ended conversion is also
required in order to translate the sensor’s differential output
into a single ended analog signal. In addition, level shifting is
necessary to convert the sensor’s 1/2 B+ common mode
voltage to an appropriate DC level. For microcomputer A/D
inputs, generally that level is from 0.3 – 1.0 V. Typical design
targets are 0.5 V at zero pressure and enough gain to produce
4.5 V at full scale. The 0.5 V zero pressure offset allows for
output saturation voltage in op amps operated with a single
supply (VEE = 0). At the other end, 4.5 V full scale keeps the
output within an A/D converter’s 5 V range with a comfortable
margin for component tolerances. The resulting 0.5 to 4.5 V
single–ended analog signal is also quite suitable for a variety
of other applications such as bar graph pressure gauges and
process monitors.
CLASSIC INSTRUMENTATION AMPLIFIER
A classic instrumentation amplifier is shown in Figure 1.
This circuit provides the gain, level shifting and differential to
single–ended conversion that are required for sensor
interface. It does not, however, provide for single supply
operation with a zero pressure offset voltage in the desired
range.
VCC
5
4
7
+
6 –
U1B
MC33274
+
R4 1k
R31k
R8 15 k
10
+
9 –
C3 0.001 µF
R10
240*
OUTPUT
R9 15 k
U1A
MC33274
–
8
U1C
MC33274
2
–
3 +
1
R5
1k
R2
1k
* NOTE: FOR MPX2020 R10 = 150 OHMS
11
VEE
Figure 1. Classic Instrumentation Amplifier
REV 2
3–284
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B+
U2
MC78L08ACP
3
I
O
G
1
C2
0.1 µF
2
C1
1 µF
R7
7.5 k
R6
ZERO
5
+ 4 7
6
–
U1B
MC33274
R8 15 k
GND
3
Freescale Semiconductor, Inc...
AN1325
XDCR1
MPX2000 SERIES
PRESSURE SENSOR
2
4
1
R4
1k
0.001 µF
C3
R10
240*
1k
12
+
13
–
14
U1D
MC33274
R3 1 k
U1C
MC33274
10
8
+
9
–
R9
R5
R2
15 k
U1A
2 MC33274
–
1
3
+
11
1k
1k
OUTPUT
* NOTE: FOR MPX2010 R10 = 150 OHMS
Figure 2. Instrumentation Amplifier Interface
To provide the desired DC offset, a slight modification is
made in Figure 2. R3 is connected to pin 14 of U1D, which
supplies a buffered offset voltage that is derived from the wiper
of R6. This voltage establishes a DC output for zero
differential input. The translation is one to one. Whatever
voltage appears at the wiper of R6 will, within component
tolerances, appear as the zero pressure DC offset voltage at
the output.
With R10 at 240 Ω gain is set for a nominal value of 125,
providing a 4 V span for 32 mV of full scale sensor output.
Setting the offset voltage to 0.75 V, results in a 0.75 V to 4.75
V output that is directly compatible with microprocessor A/D
inputs.
This circuit works reasonably well, but has several notable
limitations when made with discrete components. First, it has
a relatively large number of resistors that have to be well
matched. Failure to match these resistors degrades common
mode rejection and initial tolerance on zero pressure offset
voltage. It also has two amplifiers in one gain loop, which
makes stability more of an issue than it is in the following two
alternatives. This circuit also has more of a limitation on zero
pressure offset voltage than the other two. The minimum
output voltage of U1D restricts the minimum zero pressure
offset voltage that can be accommodated, given component
tolerances. The result is a 0.75 V zero pressure offset voltage,
compared to 0.5 V for each of the following two circuits.
Motorola Sensor Device Data
SENSOR SPECIFIC AMPLIFIER
The limitations associated with classic instrumentation
amplifiers suggest that alternate approaches to sensor
interface design are worth looking at. One such approach is
shown in Figure 3. It uses one quad op amp and several
resistors to amplify and level shift the sensor’s output.
Most of the amplification is done in U1A, which is configured
as a differential amplifier. It is isolated from the sensor’s minus
output by U1B. The purpose of U1B is to prevent feedback
current that flows through R5 and R6 from flowing into the
sensor. At zero pressure the voltage from pin 2 to pin 4 on the
sensor is zero V. For example, assume that the common
mode voltage is 4.0 V. The zero pressure output voltage at pin
1 of U1A is then 4.0 V, since any other voltage would be
coupled back to pin 2 via R6 and create a non zero bias across
U1A’s differential inputs. This 4.0 V zero pressure DC output
voltage is then level translated to the desired zero pressure
offset voltage by U1C and U1D. To see how the level
translation works, assume that the wiper of R9 is at ground.
With 4.0 V at pin 12, pin 13 is also at 4.0 V. This leaves 4.0 V
across (R3+R9), which total essentially 1 kΩ. Since no current
flows into pin 13, the same current flows through R4,
producing approximately 4.0 V across R4, as well. Adding the
voltages (4.0 + 4.0) yields 8.0 V at pin 14. Similarly 4.0 V at
pin 10 implies 4.0 V at pin 9, and the drop across R2 is 8.0 V
– 4.0 = 4.0 V. Again 4.0 V across R2 implies an equal drop
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AN1325
B+
U2
3 MC78L08ACP
I
1
O
G
2
C1
1 µF
TP2 +8 V
3
XDCR1
MPX2000 SERIES
PRESSURE SENSOR
GND
R8
1.5 k
+
2 –
3
4
Freescale Semiconductor, Inc...
R9 200
2
1
4
C2
0.1 µF
1
U1A
MC33274
10
+
9 –
R6 7.5 k
R5
120*
U1B
6 MC33274
7
–
5 +
11
U1C
MC33274
8
OUT
R1 2 k
R2 2 k
12
R3
820
+
13 –
14
U1D
MC33274
R4 1 k
ZERO
CAL.
* NOTE: FOR MPX2010 R5 = 75 OHMS
Figure 3. Sensor Specific Amplifier
across R1, and the voltage at pin 8 is 4.0 V – 4.0 V = 0 V. In
practice, the output of U1C will not go all the way to ground,
and the voltage injected by R8 at the wiper of R9 is
approximately translated into a DC offset.
Gain is approximately equal to R6/R5(R1/R2+1), which
predicts 125 for the values shown in Figure 3. A more exact
calculation can be performed by doing a nodal analysis, which
yields 127. Cascading the gains of U1A and U1C using
standard op amp gain equations does not give an exact result,
because the sensor’s negative going differential signal at pin
4 subtracts from the DC level that is amplified by U1C. Setting
offset to 0.5 V results in an analog zero to full scale range of
0.5 to 4.5 V. For this DC output voltage to be independent of
the sensor’s common mode voltage it is necessary to satisfy
the condition that R1/R2 = (R3+R9)/R4.
This approach to interface amplifier design is an
improvement over the classic instrument amplifier in that it
uses fewer resistors, is inherently more stable, and provides
a zero pressure output voltage that can be targeted at .5 V. It
has the same tolerance problem from matching discrete
resistors that is associated with classic instrument amplifiers.
SENSOR MINI AMP
Further improvements can be made with the circuit that is
shown in Figure 4. It uses one dual op amp and several
resistors to amplify and level shift the sensor’s output. To see
how this amplifier works, let’s simplify it by grounding the
output of voltage divider R3, R5 and assuming that the divider
impedance is added to R6, such that R6 = 12.4 k. If the
common mode voltage at pins 2 and 4 of the sensor is 4.0 V,
3–286
then pin 2 of U2A and pin 6 of U2B are also at 4.0 V. This puts
4.0 V across R6, producing 323 µA. Assuming that the current
in R4 is equal to the current in R6, 323 µA • 100 Ω produces
a 32 mV drop across R4 which adds to the 4.0 V at pin 2. The
output voltage at pin 1 of U2A is, therefore, 4.032 V. This puts
4.032 – 4.0 V across R2, producing 43 µA. The same current
flowing through R1 again produces a voltage drop of 4.0 V,
which sets the output at zero. Substituting a divider output
greater than zero into this calculation reveals that the zero
pressure output voltage is equal to the output voltage of
divider R3, R5. For this DC output voltage to be independent
of the sensor’s common mode voltage it is necessary to satisfy
the condition that R1/R2 = R6/R4, where R6 includes the
divider impedance.
Gain can be determined by assuming a differential output at
the sensor and going through the same calculation. To do this
assume 100 mV of differential output, which puts pin 2 of U2A
at 3.95 V, and pin 6 of U2B at 4.05 V. Therefore, 3.95 V is
applied to R6, generating 319 uA. This current flowing through
R4 produces 31.9 mV, placing pin 1 of U2A at 3950 mV + 31.9
mV = 3982 mV. The voltage across R2 is then 4050 mV –
3982 mV = 68 mV, which produces a current of 91 µA that
flows into R1. The output voltage is then 4.05 V + (91 µA •
93.1 k) = 12.5 V. Dividing 12.5 V by the 100 mV input yields
a gain of 125, which provides a 4 V span for 32 mV of full
scale sensor output. Setting divider R3, R5 at 0.5 V results
in a 0.5 V to 4.5 V output that is comparable to the other two
circuits.
This circuit performs the same function as the other two with
significantly fewer components and lower cost. In most cases
it is the optimum choice for a low cost interface amplifier.
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AN1325
B+
C1
0.2 µF
U1
3 MC78L08ACP
I
1
O
G
C2
2
0.2 µF
5
+
6 –
3
2
4
1
XDCR1
MPX2000 SERIES
SENSOR
R3
39.2 k
1%
R7
TRIM
U1B
MC33272
1
+
2 –
4
3
Freescale Semiconductor, Inc...
7
OUT
U2B
MC33272
R1 93.1 k 1%
C2 0.001 µF
GND
R6
11 k
1%
R5
1.33 k
1%
8
NOTES:
R7 IS NOMINALLY 39.2 k AND SELECTED FOR ZERO PRESSURE VOUT = 0.5 V
FOR MPX2010 SENSORS R1 = 150 k AND R4 = 61.9 OHMS
R2
750
1%
R4
100
1%
Figure 4. Sensor Mini Amp
PERFORMANCE
Performance differences between the three topologies are
minor. Accuracy is much more dependent upon the quality of
the resistors and amplifiers that are used and less dependent
on which of the three circuits are chosen. For example, input
offset voltage error is essentially the same for all three circuits.
To a first order approximation, it is equal to total gain times the
difference in offset between the two amplifiers that are directly
tied to the sensor. Errors due to resistor tolerances are
somewhat dependent upon circuit topology. However, they
are much more dependent upon the choice of resistors.
Choosing 1% resistors rather than 5% resistors has a much
larger impact on performance than the minor differences that
result from circuit topology. Assuming a zero pressure offset
adjustment, any of these circuits with an MPX2000 series
sensor, 1% resistors and an MC33274 amplifier results in a
± 5% pressure to voltage translation from 0 to 50° C. Software
calibration can significantly improve these numbers and
eliminate the need for analog trim.
CONCLUSION
Although the classic instrumentation amplifier is the best
known and most frequently used sensor interface amplifier, it
is generally not the optimal choice for inexpensive circuits
made from discrete components. The circuit that is shown in
Motorola Sensor Device Data
Figure 4 performs the same interface function with
significantly fewer components, less board space and at a
lower cost. It is generally the preferred interface topology for
MPX2000 series semiconductor pressure sensors.
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MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
Barometric Pressure Measurement Using
Semiconductor Pressure Sensors
AN1326
Prepared by: Chris Winkler and Jeff Baum
Discrete Applications Engineering
Freescale Semiconductor, Inc...
ABSTRACT
The most recent advances in silicon micromachining
technology have given rise to a variety of low–cost pressure
sensor applications and solutions. Certain applications had
previously been hindered by the high–cost, large size, and
overall reliability limitations of electromechanical pressure
sensing devices. Furthermore, the integration of on–chip
temperature compensation and calibration has allowed a
significant improvement in the accuracy and temperature
stability of the sensor output signal. This technology allows for
DIGIT1
the development of both analog and microcomputer–based
systems that can accurately resolve the small pressure
changes encountered in many applications. One particular
application of interest is the combination of a silicon pressure
sensor and a microcontroller interface in the design of a digital
barometer. The focus of the following documentation is to
present a low–cost, simple approach to designing a digital
barometer system.
DIGIT2
DIGIT3
DIGIT4
MCU
SIGNAL CONDITIONING
PRESSURE
SENSOR
Figure 1. Barometer System
REV 1
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INTRODUCTION
AN1326
Table 1. Altitude versus Pressure Data
Figure 1 shows the overall system architecture chosen for
this application. This system serves as a building block, from
which more advanced systems can be developed. Enhanced
accuracy, resolution, and additional features can be
integrated in a more complex design.
There are some preliminary concerns regarding the
measurement of barometric pressure which directly affect the
design considerations for this system. Barometric pressure
refers to the air pressure existing at any point within the earth’s
atmosphere. This pressure can be measured as an absolute
pressure, (with reference to absolute vacuum) or can be
referenced to some other value or scale. The meteorology and
avionics industries traditionally measure the absolute
pressure, and then reference it to a sea level pressure value.
This complicated process is used in generating maps of
weather systems. The atmospheric pressure at any altitude
varies due to changing weather conditions over time.
Therefore, it can be difficult to determine the significance of a
particular pressure measurement without additional
information. However, once the pressure at a particular
location and elevation is determined, the pressure can be
calculated at any other altitude. Mathematically, atmospheric
pressure is exponentially related to altitude. This particular
system is designed to track variations in barometric pressure
once it is calibrated to a known pressure reference at a given
altitude.
For simplification, the standard atmospheric pressure at
sea level is assumed to be 29.9 in–Hg. “Standard” barometric
pressure is measured at particular altitude at the average
weather conditions for that altitude over time. The system
described in this text is specified to accurately measure
barometric pressure variations up to altitudes of 15,000 ft. This
altitude corresponds to a standard pressure of approximately
15.0 in–Hg. As a result of changing weather conditions, the
standard pressure at a given altitude can fluctuate
approximately ±1 in–Hg. in either direction. Table 1 indicates
standard barometric pressures at several altitudes of interest.
Altitude (Ft.)
Pressure (in–Hg)
0
29.92
500
29.38
1,000
28.85
6,000
23.97
10,000
20.57
15,000
16.86
SYSTEM OVERVIEW
In order to measure and display the correct barometric
pressure, this system must perform several tasks. The
measurement strategy is outlined below in Figure 2. First,
pressure is applied to the sensor. This produces a proportional
differential output voltage in the millivolt range. This signal
must then be amplified and level–shifted to a single–ended,
microcontroller (MCU) compatible level (0.5 – 4.5 V) by a
signal conditioning circuit. The MCU will then sample the
voltage at the analog–to–digital converter (A/D) channel input,
convert the digital measurement value to inches of mercury,
and then display the correct pressure via the LCD interface.
This process is repeated continuously.
There are several significant performance features
implemented into this system design. First, the system will
digitally display barometric pressure in inches of mercury, with
a resolution of approximately one–tenth of an inch of mercury.
In order to allow for operation over a wide altitude range (0 –
15,000 ft.), the system is designed to display barometric
pressures ranging from 30.5 in–Hg. to a minimum of 15.0
in–Hg. The display will read “lo” if the pressure measured is
below 30.5 in–Hg. These pressures allow for the system to
operate with the desired resolution in the range from sea–level
to approximately 15,000 ft. An overview of these features is
shown in Table 2.
Table 2. System Features Overview
Display Units
MPX2100AP
PRESSURE
SENSOR
SIGNAL
COND.
AMPLIFIER
MC68HC11E9
MICRO–
CONTROLLER
CLOCK SYNCH
in–Hg
Resolution
0.1 in–Hg.
System Range
15.0 – 30.5 in–Hg.
Altitude Range
0 – 15,000 ft.
DATA
DESIGN OVERVIEW
4–DIGIT LCD
& MC145453
DISPLAY DRIVER
Figure 2. Barometer System Block Diagram
Motorola Sensor Device Data
The following sections are included to detail the system
design. The overall system will be described by considering
the subsystems depicted in the system block diagram, Figure
2. The design of each subsystem and its function in the overall
system will be presented.
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AN1326
Table 3. MPX2100AP Electrical Characteristics
Characteristic
Symbol
Minimum
Pressure Range
POP
0
Supply Voltage
VS
Full Scale Span
VFSS
Zero Pressure Offset
38.5
Max
Unit
100
kPa
10
16
Vdc
40
41.5
mV
±1.0
mV
Voff
Sensitivity
Freescale Semiconductor, Inc...
Typical
S
0.4
mv/kPa
Linearity
0.05
%FSS
Temperature Effect on Span
0.5
%FSS
Temperature Effect on Offset
0.2
%FSS
Pressure Sensor
The first and most important subsystem is the pressure
transducer. This device converts the applied pressure into a
proportional, differential voltage signal. This output signal will
vary linearly with pressure. Since the applied pressure in this
application will approach a maximum level of 30.5 in–Hg. (100
kPa) at sea level, the sensor output must have a linear output
response over this pressure range. Also, the applied pressure
must be measured with respect to a known reference pressure,
preferably absolute zero pressure (vacuum). The device should
also produce a stable output over the entire operating
temperature range.
The desired sensor for this application is a temperature
compensated and calibrated, semiconductor pressure
transducer, such as the Motorola MPXM2102A series sensor
family. The MPX2000 series sensors are available in
full–scale pressure ranges from 10 kPa (1.5 psi) to 200 kPa
(30 psi). Furthermore, they are available in a variety of
pressure configurations (gauge, differential, and absolute)
and porting options. Because of the pressure ranges involved
with barometric pressure measurement, this system will
employ an MPXM2102AS (absolute with single port). This
device will produce a linear voltage output in the pressure
range of 0 to 100 kPa. The ambient pressure applied to the
single port will be measured with respect to an evacuated
cavity (vacuum reference). The electrical characteristics for
this device are summarized in Table 3.
As indicated in Table 3, the sensor can be operated at
different supply voltages. The full–scale output of the sensor,
which is specified at 40 mV nominally for a supply voltage of
10 Vdc, changes linearly with supply voltage. All non–digital
circuitry is operated at a regulated supply voltage of 8 Vdc.
Therefore, the full–scale sensor output (also the output of the
sensor at sea level) will be approximately 32 mV.
ǒ
8
10
40 mV
Ǔ
(30.5
* 15.0)in-Hg * 10 steps
+ 155 steps
Hg
The span voltage can now be determined. The resolution
provided by an 8–bit A/D converter with low and high voltage
references of zero and five volts, respectively, will detect 19.5
mV of change per step.
V
RH
+ 5 V,
V
RL
+0 V
Sensor Output at 30.5 in–Hg = 32.44 mV
Sensor Output at 15.0 in–Hg = 16.26 mV
∆Sensor Output = ∆SO = 16.18 mV
The sensor output voltage at the systems minimum range
(15 in–Hg.) is approximately 16.2 mV. Thus, the sensor output
over the intended range of operations is expected to vary from
32 to 16.2 mV. These values can vary slightly for each sensor
as the offset voltage and full–scale span tolerances indicate.
3–290
Signal Conditioning Circuitry
In order to convert the small–signal differential output signal
of the sensor to MCU compatible levels, the next subsystem
includes signal conditioning circuitry. The operational
amplifier circuit is designed to amplify, level–shift, and ground
reference the output signal. The signal is converted to a
single–ended, 0.5 – 4.5 Vdc range. The schematic for this
amplifier is shown in Figure 3.
This particular circuit is based on classic instrumentation
amplifier design criteria. The differential output signal of the
sensor is inverted, amplified, and then level–shifted by an
adjustable offset voltage (through Roffset1). The offset voltage
is adjusted to produce 0.5 volts at the maximum barometric
pressure (30.5 in–Hg.). The output voltage will increase for
decreasing pressure. If the output exceeds 5.1 V, a zener
protection diode will clamp the output. This feature is included
to protect the A/D channel input of the MCU. Using the transfer
function for this circuit, the offset voltage and gain can be
determined to provide 0.1 in–Hg of system resolution and the
desired output voltage level. The calculation of these
parameters is illustrated below.
In determining the amplifier gain and range of the trimmable
offset voltage, it is necessary to calculate the number of steps
used in the A/D conversion process to resolve 0.1 in–Hg.
Gain
V
+ 3.04
DSO + 187
Note: 30.5 in–Hg and 15.0 in–Hg are the assumed
maximum and minimum absolute pressures, respectively.
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a 16–bit timer, an SPI (Serial Peripheral Interface –
synchronous), and SCI (Serial Communications Interface –
asynchronous), and a maximum of 40 I/O lines. This device is
available in several package configurations and product
variations which include additional RAM, EEPROM, and/or
I/O capability. The software used in this application was
developed using the MC68HC11 EVB development system.
The following software algorithm outlines the steps used to
perform the desired digital processing. This system will
convert the voltage at the A/D input into a digital value, convert
this measurement into inches of mercury, and output this data
serially to an LCD display interface (through the on–board
SPI). This process is outlined in greater detail below:
This gain is then used to determine the appropriate resistor
values and offset voltage for the amplifier circuit defined by the
transfer function shown below.
Freescale Semiconductor, Inc...
V out
+*
ƪ ƫ
R2
R1
)1
*
AN1326
DV ) V off
∆V is the differential output of the sensor.
The gain of 187 can be implemented with:
R1 ≈ R3 = 121 Ω
R2 ≈ R4 = 22.6 k Ω.
Choosing Roffset1 to be 1 k Ω and Roffset2 to be 2.5 k Ω, Vout
is 0.5 V at the presumed maximum barometric pressure of
30.5 in–Hg. The maximum pressure output voltage can be
trimmed to a value other than 0.5 V, if desired via Roffset1. In
addition, the trimmable offset resistor is incorporated to
provide offset calibration if significant offset drift results from
large weather fluctuations.
The circuit shown in Figure 3 employs an MC33272
(low–cost, low–drift) dual operational amplifier IC. In order to
control large supply voltage fluctuations, an 8 Vdc regulator,
MC78L08ACP, is used. This design permits use of a battery
for excitation.
1. Set up and enable A/D converter and SPI interface.
2. Initialize memory locations, initialize variables.
3. Make A/D conversion, store result.
4. Convert digital value to inches of mercury.
5. Determine if conversion is in system range.
6a. Convert pressure into decimal display digits.
6b. Otherwise, display range error message.
7. Output result via SPI to LCD driver device.
The signal conditioned sensor output signal is connected to
pin PE5 (Port E–A/D Input pin). The MCU communicates to
the LCD display interface via the SPI protocol. A listing of the
assembly language source code to implement these tasks is
included in the appendix. In addition, the software can be
downloaded directly from the Motorola MCU Freeware
Bulletin Board (in the MCU directory). Further information is
included at the beginning of the appendix.
Microcontroller Interface
The low cost of MCU devices has allowed for their use as
a signal processing tool in many applications. The MCU used
in this application, the MC68HC11, demonstrates the power of
incorporating intelligence into such systems. The on–chip
resources of the MC68HC11 include: an 8 channel, 8–bit A/D,
+12 V
U1
MC78L08ACP
IN
VS = 8 V
OUT
C1
0.33 µF
U2B
MC33272
MPXM2102AS
GROUND
3
C2
0.33 µF
S–
2
Vout
+
–
1
5.1 V
2 ZENER
4
1
1
2
S+
Roffset1
1kΩ
Roffset2
2.5 k Ω
1
1
1
2
R3
121 Ω
U2A
MC33272
+
–
2
2
R4
22.6 k Ω
R2
22.6 k W
1
2
R1
121 Ω
Figure 3. Signal Conditioning Circuit
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AN1326
LCD Interface
In order to digitally display the barometric pressure
conversion, a serial LCD interface was developed to
communicate with the MCU. This system includes an
MC145453 CMOS serial interface/LCD driver, and a 4–digit,
non–multiplexed LCD. In order for the MCU to communicate
correctly with the interface, it must serially transmit six bytes
for each conversion. This includes a start byte, a byte for each
of the four decimal display digits, and a stop byte. For
formatting purposes, decimal points and blank digits can be
displayed through appropriate bit patterns. The control of
display digits and data transmission is executed in the source
code through subroutines BCDCONV, LOOKUP, SP12LCD,
and TRANSFER. A block diagram of this interface is included
below.
CONCLUSION
Freescale Semiconductor, Inc...
This digital barometer system described herein is an
excellent example of a sensing system using solid state
components and software to accurately measure barometric
pressure. This system serves as a foundation from which
more complex systems can be developed. The MPXM2102A
series pressure sensors provide the calibration and
temperature compensation necessary to achieve the desired
accuracy and interface simplicity for barometric pressure
sensing applications.
+5 V
BP
BP
20
VDD
BP IN
BP OUT
DIGIT1
OSC IN
DIGIT2
DIGIT3
DIGIT4
OUT 33
MC145453
MC68HC11
MOSI
SCK
DATA
CLOCK
VSS
OUT1
1
Figure 4. LCD Display Interface Diagram
3–292
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AN1326
APPENDIX
MC68HC11 Barometer Software Available on:
Freescale Semiconductor, Inc...
Motorola Electronic Bulletin Board
MCU Freeware Line
8–bit, no parity, 1 stop bit
1200/300 baud
(512) 891–FREE (3733)
*
*
*
*
*
*
*
*
*
*
*
BAROMETER APPLICATIONS PROJECT – Chris Winkler
Developed: October 1st, 1992
– Motorola Discrete Applications
This code will be used to implement an MC68HC11 Micro–Controller
as a processing unit for a simple barometer system.
The HC11 will interface with an MPX2100AP to monitor,store
and display measured Barometric pressure via the 8–bit A/D channel
The sensor output (32mv max) will be amplified to .5 – 2.5 V dc
The processor will interface with a 4–digit LCD (FE202) via
a Motorola LCD driver (MC145453) to display the pressure
within +/– one tenth of an inch of mercury.
The systems range is 15.0 – 30.5 in–Hg
*
*
*
*
A/D & CPU Register Assignment
This code will use index addressing to access the
important control registers. All addressing will be
indexed off of REGBASE, the base address for these registers.
REGBASE EQU
ADCTL
ADR2
ADOPT
PORTB
PORTD
DDRD
SPCR
SPSR
SPDR
$1000
EQU
EQU
EQU
EQU
EQU
EQU
EQU
EQU
EQU
$30
$32
$39
$04
$08
$09
$28
$29
$2A
* register
*
*
*
*
*
*
*
*
*
base of control register
offset of A/D control register
offset of A/D results register
offset for A/D option register location
Location of PORTB used for conversion
PORTD Data Register Index
offset of Data Direction Reg.
offset of SPI Control Reg.
offset of SPI Status Reg.
offset of SPI Data Reg.
*
*
*
*
User Variables
The following locations are used to store important measurements
and calculations used in determining the altitude. They
are located in the lower 256 bytes of user RAM
DIGIT1
DIGIT2
DIGIT3
DIGIT4
COUNTER
POFFSET
SENSOUT
RESULT
FLAG
EQU
EQU
EQU
EQU
EQU
EQU
EQU
EQU
*
*
*
*
*
*
*
*
*
*
*
*
*
MAIN PROGRAM
The conversion process involves the following steps:
*
*
*
This process is continually repeated as the loop CONVERT
runs unconditionally through BRA (the BRANCH ALWAYS statement)
Repeats to step 3 indefinitely.
$0001
$0002
$0003
$0004
$0005
$0010
$0012
$0014
EQU
*
*
*
*
*
*
*
*
$0016
BCD blank digit (not used)
BCD tens digit for pressure
BCD tenths digit for pressure
BCD ones digit for pressure
Variable to send 5 dummy bytes
Storage Location for max pressure offset
Storage location for previous conversion
Storage of Pressure(in Hg) in hex format
* Determines if measurement is within range
1.
2.
3.
4.
5.
a.
b.
6.
7.
8.
Motorola Sensor Device Data
Set–Up SPI device–
Set–Up A/D, Constants
Read A/D, store sample
Convert into in–Hg
Determine FLAG condition IN_HG
Display error
Continue Conversion
Convert hex to BCD format BCDCONV
Convert LCD display digits
Output via SPI to LCD
SPI_CNFG
SET_UP
ADCONV
IN_HG
ERROR
INRANGE
LOOKUP
SPI2LCD
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AN1326
CONVERT BSR
*
*
*
*
ORG
LDX
BSR
BSR
ADCONV
BSR
BSR
DELAY
IN_HG
* DESIGNATES START OF MEMORY MAP FOR USER CODE
* Location of base register for indirect adr
* Set–up SPI Module for data X–mit to LCD
* Power–Up A/D, initialize constants
* Calls subroutine to make an A/D conversion
* Delay routine to prevent LCD flickering
* Converts hex format to in of Hg
The value of FLAG passed from IN_HG is used to determine
If a range error has occurred. The following logical
statements are used to either allow further conversion or jump
to a routine to display a range error message.
LDAB
CMPB
BEQ
BSR
BRA
*
Freescale Semiconductor, Inc...
$C000
#REGBASE
SPI_CNFG
SET_UP
FLAG
#$80
INRANGE
ERROR
OUTPUT
*
*
*
system
*
* Branches
Determines if an range Error has ocurred
If No Error detected (FLAG=$80) then
will continue conversion process
If error occurs (FLAG<>80), branch to ERROR
to output ERROR code to display
No Error Detected, Conversion Process Continues
INRANGE JSR
BCDCONV
JSR
LOOKUP
OUTPUT
JSR
SPI2LCD
* Output transmission to LCD
BRA
CONVERT
* Continually converts using Branch Always
*
*
*
Subroutine SPI_CNFG
Purpose is to initialize SPI for transmission
and clear the display before conversion.
SPI_CNFG BSET
PORTD,X #$20
LDAA
#$38
STAA
DDRD,X
LDAA
STAA
#$5D
SPCR,X
LDAA
STAA
LDAA
#$5
COUNTER
SPSR,X
CLRA
ERASELCD JSR
* Converts Hex Result to BCD
* Uses Look–Up Table for BCD–Decimal
* Set SPI SS Line High to prevent glitch
* Initializing Data Direction for Port D
* Selecting SS, MOSI, SCK as outputs only
* Initialize SPI–Control Register
* selecting SPE,MSTR,CPOL,CPHA,CPRO
* sets counter to X–mit 5 blank bytes
* Must read SPSR to clear SPIF Flag
* Transmission of Blank Bytes to LCD
TRANSFER
* Calls subroutine to transmit
DEC
COUNTER
BNE
ERASELCD
RTS
*
*
*
SET_UP
Subroutine SET_UP
Purpose is to initialize constants and to power–up A/D
and to initialize POFFSET used in conversion purposes.
LDAA
#$90
* selects ADPU bit in OPTION register
STAA
ADOPT,X
* Power–Up of A/D complete
LDD
#$0131+$001A
* Initialize POFFSET
STD
POFFSET
* POFFSET = 305 – 25 in hex
LDAA
#$00
* or Pmax + offset voltage (5 V)
RTS
*
*
*
Subroutine DELAY
Purpose is to delay the conversion process
to minimize LCD flickering.
DELAY
OUTLOOP LDB
INLOOP
DECB
LDA
#$FF
#$FF
BNE
DECA
BNE
RTS
INLOOP
* Loop for delay of display
* Delay = clk/255*255
OUTLOOP
*
*
*
Subroutine ADCONV
Purpose is to read the A/D input, store the conversion into
SENSOUT. For conversion purposes later.
ADCONV
LDX
3–294
#REGBASE
* loads base register for indirect addressing
LDAA
#$25
STAA
ADCTL,X
* initializes A/D cont. register SCAN=1,MULT=0
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WTCONV
*
*
*
*
IN_HG
Freescale Semiconductor, Inc...
TOHIGH
BRCLR
ADCTL,X #$80 WTCONV
LDAB
ADR2,X
CLRA
STD
SENSOUT
RTS
AN1326
* Wait for completion of conversion flag
* Loads conversion result into Accumulator
* Stores conversion as SENSOUT
Subroutine IN_HG
Purpose is to convert the measured pressure SENSOUT, into
units of in–Hg, represented by a hex value of 305–150
This represents the range 30.5 – 15.0 in–Hg
LDD
POFFSET
* Loads maximum offset for subtraction
SUBD
SENSOUT
* RESULT = POFFSET–SENSOUT in hex format
STD
RESULT
* Stores hex result for P, in Hg
CMPD
#305
BHI
TOHIGH
LDAB
TOLOW
CMPD
BLO
#150
TOLOW
LDAB
STAB
BRA
#$80
FLAG
END_CONV
#$FF
STAB
BRA
FLAG
END_CONV
LDAB
STAB
#$00
FLAG
END_CONV RTS
*
*
*
*
Subroutine ERROR
This subroutine sets the display digits to output
an error message having detected an out of range
measurement in the main program from FLAG
ERROR
SET_HI
LDAB
LDAB
STAB
STAB
#$00
DIGIT1
DIGIT4
* Initialize digits 1,4 to blanks
LDAB
CMPB
BNE
FLAG
#$00
SET_HI
* FLAG is used to determine
* if above or below range.
* If above range GOTO SET_HI
LDAB
STAB
LDAB
STAB
BRA
#$0E
DIGIT2
#$7E
DIGIT3
END_ERR
* ELSE display LO on display
* Set DIGIT2=L,DIGIT3=O
#$37
STAB
LDAB
STAB
DIGIT2
#$30
DIGIT3
* GOTO exit of subroutine
* Set DIGIT2=H,DIGIT3=1
END_ERR RTS
*
*
*
*
*
Subroutine BCDCONV
Purpose is to
uses standard
Divide HEX/10
process until
BCDCONV LDAA
CONVLP
*
LDX
#$00
STAA
STAA
STAA
LDY
LDD
#$A
IDIV
STAB
DEY
CPX
XGDX
BNE
LDX
RTS
convert ALTITUDE from hex to BCD
HEX–BCD conversion scheme
store Remainder, swap Q & R, repeat
remainder = 0.
* Default Digits 2,3,4 to 0
DIGIT2
DIGIT3
DIGIT4
#DIGIT4
RESULT
* Conversion starts with lowest digit
* Load voltage to be converted
* Divide hex digit by 10
* Quotient in X, Remainder in D
* stores 8 LSB’s of remainder as BCD digit
0,Y
#$0
* Determines if last digit stored
* Exchanges remainder & quotient
CONVLP
#REGBASE
* Reloads BASE into main program
Subroutine LOOKUP
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AN1326
*
*
*
*
*
Purpose is to implement a Look–Up conversion
The BCD is used to index off of TABLE
where the appropriate hex code to display
that decimal digit is contained.
DIGIT4,3,2 are converted only.
LOOKUP
LDX
TABLOOP DEX
#DIGIT1+4
LDY
LDAB
ABY
LDAA
STAA
CPX
BNE
#TABLE
0,X
0,Y
0,X
#DIGIT2
TABLOOP
* Counter starts at 5
* Start with Digit4
* Loads table base into Y–pointer
* Loads current digit into B
* Adds to base to index off TABLE
* Stores HEX segment result in A
* Loop condition complete, DIGIT2 Converted
RTS
Freescale Semiconductor, Inc...
*
*
*
*
*
*
Subroutine SPI2LCD
Purpose is to output digits to LCD via SPI
The format for this is to send a start byte,
four digits, and a stop byte. This system
will have 3 significant digits: blank digit
and three decimal digits.
*
Sending LCD Start Byte
SPI2LCD LDX
#REGBASE
LDAA
SPSR,X
LDAA
#$02
BSR
TRANSFER
*
LDAA
ORA
STAA
DIGIT3
#$80
DIGIT3
LDAA
STAA
#$00
DIGIT1
* Reads to clear SPIF flag
* Byte, no colon, start bit
* Transmit byte
Initializing decimal point & blank digit
* Sets MSB for decimal pt.
* after digit 3
* Set 1st digit as blank
*
Sending four decimal digits
LDY
LDAA
BSR
INY
CPY
BNE
DLOOP
#DIGIT1
0,Y
TRANSFER
* Pointer set to send 4 bytes
* Loads digit to be x–mitted
* Transmit byte
* Branch until both bytes sent
#DIGIT4+1
DLOOP
*
Sending LCD Stop Byte
LDAA
BSR
#$00
TRANSFER
* end byte requires all 0’s
* Transmit byte
RTS
*
*
*
Subroutine TRANSFER
Purpose is to send data bits to SPI
and wait for conversion complete flag bit to be set.
TRANSFER LDX
XMIT
#REGBASE
BCLR
STAA
BRCLR
BSET
LDAB
PORTD,X #$20
* Assert SS Line to start X–misssion
SPDR,X
* Load Data into Data Reg.,X–mit
SPSR,X #$80 XMIT * Wait for flag
PORTD,X #$20
* DISASSERT SS Line
SPSR,X
* Read to Clear SPI Flag
RTS
*
*
Location for FCB memory for look–up table
There are 11 possible digits: blank, 0–9
TABLE
3–296
FCB
END
$7E,$30,$6D,$79,$33,$5B,$5F,$70,$7F,$73,$00
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MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
AN1513
Mounting Techniques and Plumbing Options of
Motorola's MPX Series Pressure Sensors
Prepared by: Brian Pickard
Sensor Products Division
Semiconductor Products Sector
Freescale Semiconductor, Inc...
INTRODUCTION
Motorola offers a wide variety of ported, pressure sensing
devices which incorporate a hose barb and mounting tabs.
They were designed to give the widest range of design
flexibility. The hose barbs are 1/8″ (≈3 mm) diameter and the
tabs have #6 mounting holes. These sizes are very common
and should make installation relatively simple. More
importantly, and often overlooked, are the techniques used in
mounting and adapting the ported pressure sensors. This
application note provides some recommendations on types of
fasteners for mounting, how to use them with Motorola
sensors, and identifies some suppliers. This document also
recommends a variety of hoses, hose clamps, and their
respective suppliers.
This information applies to all Motorola MPX pressure
sensors with ported packages, which includes the packages
shown in Figure 1.
A review of recommended mounting hardware, mounting
torque, hose applications, and hose clamps is also provided
for reference.
MOUNTING HARDWARE
Mounting hardware is an integral part of package design.
Different applications will call for different types of hardware.
When choosing mounting hardware, there are three important
factors:
• permanent versus removable
• application
• cost
The purpose of mounting hardware is not only to secure the
sensor in place, but also to remove the stresses from the
sensor leads. In addition, these stresses can be high if the
hose is not properly secured to the sensor port. Screws, rivets,
push–pins, and clips are a few types of hardware that can be
used. Refer to Figure 2.
Single Side Port
Differential Port
Axial Port
Stovepipe Port
Screw
Figure 1. MPX Pressure Sensors with
Ported Packages
Rivet
Push–Pin
Figure 2. Mounting Hardware
REV 1
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AN1513
NOTES:
1. DIMENSIONING AND TOLERANCING PER
ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
–T–
C
A
E
–Q–
U
DIM
A
B
C
D
E
F
G
J
K
N
P
Q
R
S
U
V
POSITIVE
PRESSURE
N
V
B
R
PORT #2
VACUUM
PIN 1
–P–
0.25 (0.010)
M
T Q
M
1
2
3
4
S
K
F
Freescale Semiconductor, Inc...
J
T P
M
Q
S
S
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5, 1982.
2. CONTROLLING DIMENSION: INCH.
–A–
–T–
U
L
R
H
N
PORT #1
POSITIVE
PRESSURE
–Q–
B
1 2
3 4
PIN 1
K
–P–
0.25 (0.010)
J
M
T Q
S
S
F
G
D 4 PL
0.13 (0.005)
C
MILLIMETERS
MIN
MAX
27.43
28.45
18.80
19.30
16.00
16.51
0.41
0.51
4.06
4.57
1.22
1.63
2.54 BSC
0.36
0.41
5.59
6.10
1.78
2.03
3.81
4.06
3.81
4.06
11.18
11.68
17.65
18.42
21.34
21.84
4.62
4.92
G
D 4 PL
0.13 (0.005)
SEATING
PLANE
INCHES
MIN
MAX
1.080
1.120
0.740
0.760
0.630
0.650
0.016
0.020
0.160
0.180
0.048
0.064
0.100 BSC
0.014
0.016
0.220
0.240
0.070
0.080
0.150
0.160
0.150
0.160
0.440
0.460
0.695
0.725
0.840
0.860
0.182
0.194
M
T S
S
Q
DIM
A
B
C
D
F
G
H
J
K
L
N
P
Q
R
S
U
INCHES
MIN
MAX
1.145
1.175
0.685
0.715
0.305
0.325
0.016
0.020
0.048
0.064
0.100 BSC
0.182
0.194
0.014
0.016
0.695
0.725
0.290
0.300
0.420
0.440
0.153
0.159
0.153
0.159
0.230
0.250
0.220
0.240
0.910 BSC
MILLIMETERS
MIN
MAX
29.08
29.85
17.40
18.16
7.75
8.26
0.41
0.51
1.22
1.63
2.54 BSC
4.62
4.93
0.36
0.41
17.65
18.42
7.37
7.62
10.67
11.18
3.89
4.04
3.89
4.04
5.84
6.35
5.59
6.10
23.11 BSC
S
Figure 3. Case Outline Drawings
Top: Case 371D–03, Issue C
Bottom: Case 350–05, Issue J
To mount any of the devices except Case 371–07/08 and
867E) to a flat surface such as a circuit board, the spacing and
diameter for the mounting holes should be made according to
Figure 3.
Mounting Screws
Mounting screws are recommended for making a very
secure, yet removable connection. The screws can be either
metal or nylon, depending on the application. The holes are
0.155″ diameter which fits a #6 machine screw. The screw can
be threaded directly into the base mounting surface or go
through the base and use a flat washer and nut (on a circuit
board) to secure to the device.
MOUNTING TORQUE
The torque specifications are very important. The sensor
package should not be over tightened because it can crack,
causing the sensor to leak. The recommended torque
specification for the sensor packages are as follows:
3–298
Port Style
Single side port:
port side down
port side up
Differential port (dual port)
Axial side port
Torque Range
3 – 4 in – lb
6 – 7 in – lb
9 – 10 in – lb
9 – 10 in – lb
The torque range is based on installation at room
temperature. Since the sensor thermoplastic material has a
higher TCE (temperature coefficient of expansion) than
common metals, the torque will increase as temperature
increases. Therefore, if the device will be subjected to very low
temperatures, the torque may need to be increased slightly. If
a precision torque wrench is not available, these torques all
work out to be roughly 1/2 of a turn past “finger tight” (contact)
at room temperature.
Tightening beyond these recommendations may damage
the package, or affect the performance of the device.
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Nylon Screws
Motorola recommends the use of #6 – 32 nylon screws as a
hardware option. However, they should not be torqued
excessively. The nylon screw will twist and deform under
higher than recommended torque. These screws should be
used with a nylon nut.
Freescale Semiconductor, Inc...
Rivets
Rivets are excellent fasteners which are strong and very
inexpensive. However, they are a permanent connection.
Plastic rivets are recommended because metal rivets may
damage the plastic package. When selecting a rivet size, the
most important dimension, besides diameter, is the grip range.
The grip range is the combined thickness of the sensor
package and the thickness of the mounting surface. Package
thicknesses are listed below.
Port Style
Thickness, a
Single side port
Dual side port
Axial side port
Stovepipe port
0.321″ (8.15 mm)
0.420″ (10.66 mm)
0.321″ (8.15 mm)
(Does not apply)
AN1513
listed later in this application note. Two brands of vinyl hose
are:
Hose
Wall
Thickness
Max. Press.
@ 70°F
(24°C)
Max.
Temp.
(°F)/(°C)
Clippard #3814–1
Herco Clear #0500–037
1/16″
1/16″
105
54
100/(38)
180/(82)
Tygon tubing is slightly more expensive than vinyl, but it is
the most common brand, and it is also very flexible. It also is
recommended for use at room temperature and applications
below 50 psig. This tubing is also recommended for
applications where the hose may be removed and reattached
several times. This tubing should also be used with a hose
clamp.
Grip Range = a + b
Wall
Thickness
Max. Press.
@ 73°F
(25°C)
Max. Temp.
(°F)/(°C)
1/16″
62
165/(74)
a
b
Tubing
Tygon B–44–3
Push–Pins
Plastic push pins or ITW FasTex “Christmas Tree” pins are
an excellent way to make a low cost and easily removable
connection. However, these fasteners should not be used for
permanent connections. Remember, the fastener should take
all of the static and dynamic loads off the sensor leads. This
type of fastener does not do this completely.
Urethane tubing is the most expensive of the four types
described herein. It can be used at higher pressures (up to 100
psig) and temperatures up to 100°F (38°C). It is flexible,
although its flexibility is not as good as vinyl or Tygon.
Urethane tubing is very strong and it is not necessary to use
a hose clamp, although it is recommended.
Two brands of urethane hose are:
HOSE APPLICATIONS
By using a hose, a sensor can be located in a convenient
place away from the actual sensing location which could be a
hazardous and difficult area to reach. There are many types
of hoses on the market. They have different wall thicknesses,
working pressures, working temperatures, material
compositions, and media compatibilities. All of the hoses
referenced here are 1/8″ inside diameter and 1/16″ wall
thickness, which produces a 1/4″ outside diameter. Since all
the port hose barbs are 1/8″, they require 1/8″ inside diameter
hose. The intent is for use in air only and any questions about
hoses for your specific application should be directed to the
hose manufacturer. Four main types of hose are available:
• Vinyl
• Tygon
• Urethane
• Nylon
Vinyl hose is inexpensive and is best in applications with
pressures under 50 psig and at room temperature. It is flexible
and durable and should not crack or deteriorate with age. This
type of hose should be used with a hose clamp such as those
Motorola Sensor Device Data
Hose
Wall
Thickness
Max. Press.
@ 70°F
(24°C)
Max.
Temp.
(°F)/(°C)
Clippard #3814–6
Herco Clear #0585–037
1/16″
1/16″
105
105
120/(49)
225/(107)
Nylon tubing does not work well with Motorola’s sensors. It
is typically used in high pressure applications with metal
fittings (such as compressed air).
HOSE CLAMPS
Hose clamps should be employed for use with all hoses
listed above. They provide a strong connection with the sensor
which prevents the hose from working itself off, and also
reduces the chance of leakage. There are many types of hose
clamps that can be used with the ported sensors. Here are
some of the most common hose clamps used with hoses.
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AN1513
Crimp–on Clamp
Nylon Snap
Spring Wire
Screw–on
The two clamps most recommended by Motorola are the
crimp–on clamp and the screw–on, Clippard reusable clamp.
The crimp–on type clamp is offered from both Ryan Herco
(#0929–007) and Clippard (#5000–2). Once crimped in place,
it provides a very secure hold, but it is not easily removed and
is not reusable. The Clippard, reusable hose clamp is a brass,
self–threading clamp, which provides an equally strong grip as
the crimp–on type just described. The drawback is the
reusable clamp is considerably more expensive. The nylon
snap is also reusable, however the size options do not match
the necessary outside diameter. The spring wire clamp,
common in the automotive industry, and known for its very low
cost and ease of use, also has a size matching problem.
Custom fit spring wire clamps may provide some cost savings
in particular applications.
Figure 4. Hose Clamps
SUPPLIER LIST
Hoses
Spring Wire Clamps
Bolts
Norton–Performance Plastics
Worldwide Headquarters
150 Dey Road, Wayne, NJ 07470–4599 USA
(201) 596–4700
Telex: 710–988–5834
USA
P.O. Box 3660, Akron, OH 44309–3660
USA
(216) 798–9240
FAX: (216) 798–0358
RotorClip, Inc.
187 Davidson Avenue
Somerset, NJ 08875–0461
1–800–631–5857 Ext. 255
Quality Screw and Nut Company
1331 Jarvis Avenue
Elk Grove Village, IL 60007
(312) 593–1600
Rivets and Push–Pins
Crimp–on and Nylon Clamps
ITW FasTex
195 Algonquin Road
Des Plaines, IL 60016
(708) 299–2222
FAX: (708) 390–8727
Ryan Herco Products Corporation
P.O. Box 588
Burbank, CA 91503
1–800–423–2589
FAX: (818) 842–4488
Clippard Instrument Laboratory, Inc.
7390 Colerain Rd.
Cincinnati, Ohio 45239, USA
(513) 521–4261
FAX: (513) 521–4464
Ryan Herco Products Corporation
P.O. Box 588
Burbank, CA 91503
1–800–423–2589
FAX: (818) 842–4488
3–300
Crimp–on and Screw–on Clamps
Clippard Instrument Laboratory, Inc.
7390 Colerain Rd.
Cincinnati, Ohio 45239, USA
(513) 521–4261
FAX: (513) 521–4464
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Motorola Sensor Device Data
MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR APPLICATION NOTE
AN1516
Liquid Level Control Using a
Motorola Pressure Sensor
Prepared by: JC Hamelain
Toulouse Pressure Sensor Laboratory
Semiconductor Products Sector, Toulouse, France
Freescale Semiconductor, Inc...
INTRODUCTION
Motorola Discrete Products provides a complete solution
for designing a low cost system for direct and accurate liquid
level control using an ac powered pump or solenoid valve.
This circuit approach which exclusively uses Motorola
semiconductor parts, incorporates a piezoresistive pressure
sensor with on–chip temperature compensation and a new
solid–state relay with an integrated power triac, to drive
directly the liquid level control equipment from the domestic
110/220 V 50/60 Hz ac main power line.
Depending on the application and pressure range, the sensor
may be chosen from the following portfolio. For this application
the MPXM2010GS was selected.
Device
Pressure Range
MPXM2010GS 0 to 10 kPa
MPXM2053GS 0 to 50 kPa
MPXM2102GS 0 to 100 kPa
MPXM2202GS 0 to 200 kPa
* after proper gain adjustment
Application Sensitivity*
±
±
±
±
0.01 kPa (1 mm H2O)
0.05 kPa (5 mm H2O)
0.1 kPa (10 mm H2O)
0.2 kPa (20 mm H2O)
PRESSURE SENSOR DESCRIPTION
The MPXM2000 Series pressure sensor integrates
on–chip, laser–trimmed resistors for offset calibration and
temperature compensation. The pressure sensitive element
is a patented, single piezoresistive implant which replaces the
four resistor Wheatstone bridge traditionally used by most
pressure sensor manufacturers.
Pin 3
R1
+ VS
Roff1
RS1
Rp
R2
Pin 2
+ Vout
X–ducer
Pin 4
– Vout
Roff2
RS2
Pin 1
MPAK AXIAL PORT
CASE 1320A
Laser Trimmed On–Chip
Figure 1. Pressure Sensor MPXM2000 Series
REV 2
Motorola Sensor Device Data
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AN1516
POWER OPTO ISOLATOR MOC2A60 DESCRIPTION
The MOC2A60 is a new Motorola POWER OPTO isolator
and consists of a gallium arsenide, infrared emitting diode,
which is optically coupled to a zero–cross triac driver and a
power triac. It is capable of driving a load of up to 2 A (rms)
directly from a line voltage of 220 V (50/60 Hz).
Device Schematic
9
3
2
ZVA
*
Freescale Semiconductor, Inc...
7
CASE 417
PLASTIC
PACKAGE
* Zero Voltage Activate Circuit
1, 4, 5, 6, 8.
1, 4, 5, 6, 2.
1, 4, 5, 6, 3.
1, 4, 5, 6, 7.
1, 4, 5, 6, 9.
No Pin
LED Cathode
LED Anode
Main Terminal
Main Terminal
Figure 2. MOC2A60 POWER OPTO Isolator
SIGNAL CONDITIONING
When a full range pressure is applied to the MPXM2010GS,
it will provide an output of about 20 mV (at an 8 V supply).
Therefore, for an application using only a few percent of the
pressure range, the available signal may be as low as a few
hundred microvolts. To be useful, the sensor signal must be
amplified. This is achieved via a true differential amplifier (A1
and A2) as shown in Figure 4. The GAIN ADJ (500 ohm)
resistor, RG, sets the gain to about 200.
The differential output of this stage is amplified by a second
stage (A3) with a variable OFFSET resistor. This stage
performs a differential to single–ended output conversion and
references this output to the adjustable offset voltage. This
output is then compared to a voltage (VREF = 4 V at TP2) at
the input of the third stage (A4).
This last amplifier is used as an inverted comparator
amplifier with hysteresis (Schmitt trigger) which provides a
logic signal (TP3) within a preset range variation of about 10%
of the input (selected by the ratio R9/(R9 + R7).
If the pressure sensor delivers a voltage to the input of the
Schmitt trigger (pin 13) lower than the reference voltage (pin
12), then the output voltage (pin 14) is high and the drive
current for the power stage MOC2A60 is provided. When the
3–302
sensor output increases above the reference voltage, the
output at pin 14 goes low and no drive current is available.
The amplifier used is a Motorola MC33179. This is a quad
amplifier with large current output drive capability (more than
80 mA).
OUTPUT POWER STAGE
For safety reasons, it is important to prevent any direct
contact between the ac main power line and the liquid
environment or the tank. In order to maintain full isolation
between the sensor circuitry and the main power, the
solid–state relay is placed between the low voltage circuit
(sensor and amplifier) and the ac power line used by the pump
and compressor.
The output of the last stage of the MC33179 is used as a
current source to drive the LED (light emitting diode). The
series resistor, R8, limits the current into the LED to
approximately 15 mA and guarantees an optimum drive for the
power opto–triac. The LD1 (MFOE76), which is an infrared
light emitting diode, is used as an indicator to detect when the
load is under power.
The MOC2A60 works like a switch to turn ON or OFF the
pump’s power source. This device can drive up to 2 A for an
ac load and is perfectly suited for the medium power motors
(less than 500 watts) used in many applications. It consists of
an opto–triac driving a power triac and has a zero–crossing
detection to limit the power line disturbance problems when
fast switching selfic loads. An RC network, placed in parallel
with the output of the solid–state relay is not required, but it is
good design practice for managing large voltage spikes
coming from the inductive load commutation. The load itself
(motor or solenoid valve) is connected in series with the
solid–state relay to the main power line.
EXAMPLE OF APPLICATION:
ACCURATE LIQUID LEVEL MONITORING
The purpose of the described application is to provide an
electronic system which maintains a constant liquid level in a
tank (within ± 5 mm H2O). The liquid level is kept constant in
the tank by an ac electric pump and a pressure sensor which
provides the feedback information. The tank may be of any
size. The application is not affected by the volume of the tank
but only by the difference in the liquid level. Of course, the
maximum level in the tank must correspond to a pressure
within the operating range of the pressure sensor.
LIQUID LEVEL SENSORS
Motorola has developed a piezoresistive pressure sensor
family which is very well adapted for level sensing, especially
when using an air pipe sensing method. These devices may
also be used with a bubbling method or equivalent.
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Motorola Sensor Device Data
Freescale Semiconductor, Inc.
AN1516
AC Line
Control Module
Open Pipe Before
Calibration
Pressure
Sensor
Air
Electrical
P