Data Sheet

Data Sheet
Rev. 2.12 / June 2014
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner with Diagnostic Features
Multi-Market Sensing Platforms
Precise and Deliberate
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
Brief Description
Benefits
The ZSC31015 is adjustable to nearly all piezoresistive bridge sensors. Measured and corrected
bridge values are provided at the SIG™ pin, which
can be configured as an analog voltage output or as
a one-wire serial digital output.

No external trimming components required

Simple PC-controlled configuration and
calibration via one-wire interface

High accuracy: ±0.1% FSO @ -25 to 85°C;
±0.25% FSO @ -50 to 150°C
The digital one-wire interface (OWI) can be used for
a simple PC-controlled calibration procedure to program a set of calibration coefficients into an on-chip
EEPROM. The calibrated ZSC31015 and a specific
sensor are mated digitally: fast, precise, and without
the cost overhead associated with trimming by
external devices or laser. Integrated diagnostics
functions make the ZSC31015 particularly well
suited for automotive applications.*

Single-pass calibration – quick and precise
Available Support

Evaluation Kit available

Mass Calibration System available
Support for industrial mass calibration available


Quick circuit customization possible for large
production volumes
Features












Digital compensation of sensor offset, sensitivity,
temperature drift, and non-linearity
Programmable analog gain and digital gain;
accommodates bridges with spans < 1mV/V
and high offset
Many diagnostic features on chip (e.g., EEPROM
signature, bridge connection checks, bridge short
detection, power loss detection)
Independently programmable high and low
clipping levels
24-bit customer ID field for module traceability
Internal temperature compensation reference
(no external components)
Option for external temperature compensation
with addition of single diode
Output options: rail-to-rail ratiometric analog
voltage (12-bit resolution), absolute analog
voltage, digital one-wire interface
Fast power-up to data out response; output
available 5ms after power-up
Current consumption depends on programmed
sample rate: 1mA down to 250A (typical)
Fast response time: 1ms (typical)
High voltage protection up to 30V with
external JFET
Physical Characteristics

Wide operation temperature: –50°C to +150°C

Supply voltage 2.7 to 5.5V; with external JFET,
5.5 to 30V

Small SOP8 package
ZSC31015 Application Circuit
Vsupply
+2.7 to +5.5 V
VDD
SIG™
OUT/OWI
ZSC31015
VBP
Vgate
VBN
VSS
0.1 F
Ground
* Not AEC-Q100-qualified.
For more information, contact ZMDI via [email protected]
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12— June 3, 2014. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated,
stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
ZSC31015 Block Diagram
JFET1
(Optional if supply is 2.7 to 5.5 V)
S
0.1 F
Highly Versatile Applications
in Many Markets Including







VDD (2.7 to 5.5 V)
Industrial
Building Automation
Office Automation
White Goods
Automotive *
Portable Devices
Your Innovative Designs
Vgate
RBicdLite
PTAT
Sensor
Diagnostics
Temperature
Reference
VDD
Regulator
VBP
INMUX
PREAMP
Power Save
EEPROM
with Charge
Pump
Ext Temp
(Optional)
Bsink
POR/Oscillator
12-Bit
DAC
ZSC31015
A
VBN
Optional
Ext. Diode
for Temp
5.5 V to 30 V
VSUPPLY
D
_
D
14-Bit ADC
Digital
Core
SIGTM
+
0 V to 1 V
Ratiometric
Rail-to-Rail
OWI/ZACwireTM
OUTBUF1
ZACwireTM
Interface
Power Lost
Diagnostic
Analog Block
Digital Block
VSS
* Not AEC-Q100-qualified.
Rail-to-Rail Ratiometric Voltage Output Applications
Absolute Analog Voltage Output Applications
BSS169
Vsupply
S
+2.7 to +5.5 V
1 Bsink
2 VBP
3 ExtTemp
4 VBN
Optional Bsink
VSS 8
TM
Sig
OUT
7
VSS 8
2 VBP
SigTM 7
3 ExtTemp
VDD 6
Vgate 5
ZSC31015
1 Bsink
4 VBN
0.1 F
Optional Bsink
D
Vsupply
+5.5 to +30 V
OUT
VDD 6
Vgate 5
0.1 F
ZSC31015
Ground
Ground
Ordering Examples (See section 11 of the data sheet for additional temperature range options.)
Sales Code
Description
Package
ZSC31015EEB
ZSC31015 Die — Temperature range: -50°C to +150°C
Unsawn on Wafer
ZSC31015EEC
ZSC31015 Die — Temperature range: -50°C to +150°C
Sawn on Wafer Frame
ZSC31015EEG1
ZSC31015 SOP8 (150 mil) — Temperature range: -50°C to +150°C
Tube: add “-T” to sales code. Reel: add “-R”
ZSC31015KIT
ZSC31015 ZACwire™ SSC Evaluation Kit: Communication Board, SSC Board, Sensor
Replacement Board, USB Cable, 5 IC Samples (SOP8 150mil)
Kit
(ZACwire™ SSC Evaluation Software can be downloaded from www.zmdi.com/zsc31015)
Sales and Further Information
www.zmdi.com
[email protected]
Zentrum Mikroelektronik
Dresden AG
Global Headquarters
Grenzstrasse 28
01109 Dresden, Germany
ZMD America, Inc.
1525 McCarthy Blvd., #212
Milpitas, CA 95035-7453
USA
Central Office:
Phone +49.351.8822.306
Fax
+49.351.8822.337
USA Phone 1.855.275.9634
Phone +1.408.883.6310
Fax
+1.408.883.6358
European Technical Support
Phone +49.351.8822.7.772
Fax
+49.351.8822.87.772
DISCLAIMER: This information applies to a product under development. Its characteristics and specifications are subject to change without notice.
Zentrum Mikroelektronik Dresden AG (ZMD AG) assumes no obligation regarding future manufacture unless otherwise agreed to in writing. The
information furnished hereby is believed to be true and accurate. However, under no circumstances shall ZMD AG be liable to any customer,
licensee, or any other third party for any special, indirect, incidental, or consequential damages of any kind or nature whatsoever arising out of or
in any way related to the furnishing, performance, or use of this technical data. ZMD AG hereby expressly disclaims any liability of ZMD AG to any
customer, licensee or any other third party, and any such customer, licensee and any other third party hereby waives any liability of ZMD AG for
any damages in connection with or arising out of the furnishing, performance or use of this technical data, whether based on contract, warranty,
tort (including negligence), strict liability, or otherwise.
European Sales (Stuttgart)
Phone +49.711.674517.55
Fax
+49.711.674517.87955
Zentrum Mikroelektronik
Dresden AG, Japan Office
2nd Floor, Shinbashi Tokyu Bldg.
4-21-3, Shinbashi, Minato-ku
Tokyo, 105-0004
Japan
ZMD FAR EAST, Ltd.
3F, No. 51, Sec. 2,
Keelung Road
11052 Taipei
Taiwan
Phone +81.3.6895.7410
Fax
+81.3.6895.7301
Phone +886.2.2377.8189
Fax
+886.2.2377.8199
Zentrum Mikroelektronik
Dresden AG, Korea Office
U-space 1 Building
11th Floor, Unit JA-1102
670 Sampyeong-dong
Bundang-gu, Seongnam-si
Gyeonggi-do, 463-400
Korea
Phone +82.31.950.7679
Fax
+82.504.841.3026
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12 — June 3, 2014
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner.
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
Contents
1
Electrical Characteristics ................................................................................................................ 8
1.1. Absolute Maximum Ratings ...................................................................................................... 8
1.2. Recommended Operating Conditions ....................................................................................... 8
1.3. Electrical Parameters ............................................................................................................... 9
1.3.1. Supply/Regulation Characteristics ...................................................................................... 9
1.3.2. Parameters for Analog Front-End (AFE) ............................................................................. 9
1.3.3. Parameters for EEPROM ................................................................................................... 9
1.3.4. Parameters for A/D Converter ............................................................................................ 9
1.3.5. Parameters for Analog Output (DAC and Buffer) ................................................................ 9
1.3.6. Diagnostics ........................................................................................................................10
1.3.7. External Temperature Measurement .................................................................................10
1.3.8. Parameters for ZACwire™ Serial Interface ........................................................................10
1.3.9. Parameters for System Response .....................................................................................10
1.4. Analog Inputs versus Output Resolution..................................................................................11
2
Circuit Description .........................................................................................................................14
2.1. Signal Flow and Block Diagram ...............................................................................................14
2.2. Analog Front End ....................................................................................................................15
2.2.1. Bandgap/PTAT and PTAT Amplifier ..................................................................................15
2.2.2. Bridge Supply ....................................................................................................................15
2.2.3. PREAMP Block .................................................................................................................15
2.2.4. Analog-to-Digital Converter (ADC) .....................................................................................16
2.3. Digital Signal Processor ..........................................................................................................16
2.3.1. EEPROM ...........................................................................................................................18
2.3.2. One-Wire Interface – ZACwire™ .......................................................................................18
2.4. Output Stage ...........................................................................................................................18
2.4.1. Digital to Analog Converter (Output DAC) with Programmable Clipping Limits ..................18
2.4.2. Output Buffer .....................................................................................................................19
2.4.3. Voltage Reference Block ...................................................................................................19
2.5. Clock Generator / Power-On Reset (CLKPOR) .......................................................................21
2.5.1. Trimming the Oscillator ......................................................................................................21
2.6. Diagnostic Features ................................................................................................................21
2.6.1. EEPROM Integrity .............................................................................................................22
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
4 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
2.6.2. Sensor Connection Check .................................................................................................22
2.6.3. Sensor Short Check ..........................................................................................................23
2.6.4. Power Loss Detection ........................................................................................................23
2.6.5. ExtTemp Connection Checks ............................................................................................23
3
Functional Description ...................................................................................................................24
3.1. General Working Mode ...........................................................................................................24
3.2. ZACwire™ Communication Interface.......................................................................................26
3.2.1. Properties and Parameters ................................................................................................26
3.2.2. Bit Encoding ......................................................................................................................26
3.2.3. Write Operation from Master to ZSC31015 ........................................................................27
3.2.4. ZSC31015 Read Operations .............................................................................................27
3.2.5. High Level Protocol ...........................................................................................................30
3.3. Command/Data Bytes Encoding..............................................................................................31
3.4. Calibration Sequence ..............................................................................................................32
3.5. EEPROM Bits ..........................................................................................................................34
3.6. Calibration Math ......................................................................................................................38
3.6.1. Correction Coefficients ......................................................................................................38
3.6.2. Interpretation of Binary Numbers for Correction Coefficients .............................................38
3.7. Reading EEPROM Contents ...................................................................................................42
4
Application Circuit Examples .........................................................................................................43
4.1. Three-Wire Rail-to-Rail Ratiometric Output .............................................................................43
4.2. Absolute Analog Voltage Output..............................................................................................44
4.3. Three-Wire Ratiometric Output with Over-Voltage Protection ..................................................45
4.4. Digital Output ..........................................................................................................................45
4.5. Output Resistor/Capacitor Limits .............................................................................................45
5
EEPROM Restoration ...................................................................................................................46
5.1. Default EEPROM Contents .....................................................................................................46
5.1.1. Osc_Trim ...........................................................................................................................46
5.1.2. 1V_Trim/JFET_Trim ..........................................................................................................46
5.2. EEPROM Restoration Procedure ............................................................................................46
6
Pin Configuration and Package .....................................................................................................48
7
ESD/Latch-Up-Protection ..............................................................................................................49
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
5 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
8
Test ...............................................................................................................................................49
9
Quality and Reliability ....................................................................................................................49
10 Customization ...............................................................................................................................49
11 Part Ordering Codes .....................................................................................................................50
12 Related Documents .......................................................................................................................50
13 Definitions of Acronyms .................................................................................................................51
14 Document Revision History ...........................................................................................................52
List of Figures
Figure 2.1
Figure 2.2
Figure 3.1
Figure 3.2
Figure 3.3
Figure 3.4
Figure 3.5
Figure 3.6
Figure 3.7
Figure 3.8
Figure 3.9
Figure 4.1
Figure 4.2
Figure 4.3
Figure 5.1
Figure 6.1
Data Sheet
June 3, 2014
ZSC31015 Block Diagram ..................................................................................................................14
DAC Output Timing for Highest Update Rate .....................................................................................19
General Working Mode .......................................................................................................................25
Manchester Duty Cycle .......................................................................................................................26
19-Bit Write Frame ..............................................................................................................................27
Read Acknowledge .............................................................................................................................27
Digital Output (NOM) Bridge Readings ..............................................................................................28
Digital Output (NOM) Bridge Readings with Temperature .................................................................28
Read EEPROM Contents ...................................................................................................................29
Transmission of a Number of Data Packets .......................................................................................29
ZACwire™ Output Timing for Lower Update Rates............................................................................30
Rail-to-Rail Ratiometric Voltage Output – Temperature Compensation via External Diode ..............43
Absolute Analog Voltage Output – Temperature Compensation via Internal Temperature PTAT with
External JFET Regulation ...................................................................................................................44
Ratiometric Output, Temperature Compensation via Internal Diode ..................................................45
EEPROM Validation and Restoration Procedure ...............................................................................47
ZSC31015 Pin-Out Diagram ...............................................................................................................48
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
6 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
List of Tables
Table 1.1
Table 1.2
Table 1.3
Table 1.4
Table 2.1
Table 2.2
Table 2.3
Table 3.1
Table 3.2
Table 3.3
Table 3.4
Table 3.5
Table 3.6
Table 3.7
Table 3.8
Table 3.9
Table 3.10
Table 3.11
Table 6.1
Table 6.2
Data Sheet
June 3, 2014
ADC Resolution Characteristics for an Analog Gain of 6 ...................................................................11
ADC Resolution Characteristics for an Analog Gain of 24 .................................................................12
ADC Resolution Characteristics for an Analog Gain of 48 .................................................................12
ADC Resolution Characteristics for an Analog Gain of 96 .................................................................13
1V Reference Trim (1V vs. Trim for Nominal Process Run) ...............................................................20
Oscillator Trimming .............................................................................................................................21
Summary of Diagnostic Features .......................................................................................................22
Pin Configuration and Latch-Up Conditions .......................................................................................26
Special Measurement/Idle Time between Packets versus Update Rate ...........................................29
Total Transmission Time for Different Update Rate Settings and Output Configuration ....................30
Command/Data Bytes Encoding.........................................................................................................31
ZSC31015 EEPROM Bits ...................................................................................................................34
Correction Coefficients .......................................................................................................................38
Gain_B [13:0] Weightings ...................................................................................................................39
Offset_B Weightings ...........................................................................................................................39
Gain_T Weightings .............................................................................................................................40
Offset_T Weightings ...........................................................................................................................40
EEPROM Read Order ........................................................................................................................42
Storage and Soldering Conditions for SOP-8 Package ......................................................................48
ZSC31015 Pin Configuration ..............................................................................................................48
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
7 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
1
Electrical Characteristics
1.1.
Absolute Maximum Ratings
Note: The absolute maximum ratings are stress ratings only. The device might not function or be operable above
the operating conditions given in section 1.2. Stresses exceeding the absolute maximum ratings might also
damage the device. In addition, extended exposure to stresses above the recommended operating conditions
might affect device reliability. ZMDI does not recommend designing to the “Absolute Maximum Ratings.”
Parameter
Symbol
Min
Max
Unit
VDD
-0.3
6.0
V
Analog Supply Voltage
Voltages at Analog I/O – In Pin
VINA
-0.3
VDD+0.3
V
Voltages at Analog I/O – Out Pin
VOUTA
-0.3
VDD+0.3
V
Storage Temperature Range (10 hours)
TSTOR
-50
150
°C
Storage Temperature Range (<10 hours)
TSTOR <10h
-50
170
°C
Note: Also see Table 6.1 regarding soldering temperature and storage conditions.
1.2.
Recommended Operating Conditions
Parameter
Analog Supply Voltage to Ground
Analog Supply Voltage (with external JFET Regulator)
Common Mode Voltage
Ambient Temperature Range
1), 2)
External Capacitance between VDD and Ground
Output Load Resistance to VDD
3)
Output Load Resistance to VSS
Output Load Capacitance
Bridge Resistance
6),7)
Power-On Rise Time
1)
2)
3)
4)
5)
6)
7)
5)
3),4)
Symbol
Min
Typ
Max
Unit
VDD
2.7
5.0
5.5
V
VSUPP
5.5
7
30
V
VCM
1
VDD – 1.3
V
TAMB
-50
150
C
CVDD
100
470
nF
RL,OUT
5
RL,OUT
5
CL,OUT
1
RBR
0.3
tPON
220
k
k
10
15
nF
100
k
100
ms
Note that the maximum EEPROM programming temperature is 85°C.
If buying die, designers should use caution not to exceed maximum junction temperature by proper package selection.
Only needed for Analog Output Mode; not needed for Digital Output Mode. When a pull-down resistor is used as the load resistor, the power loss
detection diagnostic for loss of VSS cannot be assured at RL=5k; RL=10k is recommended for this configuration.
Note: for unlocked devices or during calibration, the minimum value of output load resistance to VSS is 20kΩ.
Using the output for digital calibration, CL,OUT is limited by the maximum rise time tZAC,rise. See section 1.3.8.
Note: Minimum bridge resistance is a factor if using the Bsink feature. The rds(on) of the Bsink transistor is 8 to 10Ω when operating at VDD=5V. This does
give rise to a ratiometricity inaccuracy that becomes greater with low bridge resistances.
Note: Minimum bridge resistance is important if using certain diagnostic features. It must be at least 0.3kΩ at VDD=2.7V and at least 0.6kΩ at VDD=5V for
the Sensor Short Check to function properly. For details, see section 2.6.3.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
8 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
1.3.
Electrical Parameters
See important table notes at the end of the table. Note: For parameters marked with an asterisk, there is no
verification in mass production; the parameter is guaranteed by design and/or quality observation.
Parameter
1.3.1.
Symbol
Conditions
Min
Typ
Max
Unit
2.7
5.0
5.5
V
Supply/Regulation Characteristics
Supply Voltage
VDD
Supply Current (varies with
update rate and output mode)
IDD
At minimum update rate
0.25
At maximum update rate
1.0
1.4
20
100
Temperature Coefficient – PTAT
Source *
TCPTAT
Power Supply Rejection Ratio *
PSRR
60
Power-On Reset Level
POR
1.4
1.3.2.
IIN_LEAK
2.6
V
10
nA
At 150C
100
Cycles
At 85C
100k
Cycles
At 100C
10
Years
Sensor connection and short
check must be disabled.
nWRI_EEP
Data Retention
tWRI_EEP
Parameters for A/D Converter
ADC Resolution
rADC
Integral Nonlinearity (INL)
1)
Differential Nonlinearity (DNL) *
1.3.5.
dB
Parameters for EEPROM
Number Write Cycles
1.3.4.
ppm/K
Parameters for Analog Front-End (AFE)
Leakage Current Pin VBP,VBN
1.3.3.
mA
INLADC
Based on ideal slope
DNLADC
14
Bit
-4
+4
LSB
-1
+1
LSB
Parameters for Analog Output (DAC and Buffer)
Max. Output Current
IOUT
Max. current maintaining
accuracy
Resolution
Res
Referenced to VDD
Absolute Error
EABS
DAC input to output
Differential Nonlinearity *
DNL
No missing codes
-0.9
Upper Output Voltage Limit
VOUT
RL = 5 k
95%
Lower Output Voltage Limit
VOUT
With 5k pull down, 0 to1V
output
Output Short Circuit
Protection Limit
ISC
Analog Output Noise
Peak-to-Peak
VNOISE,PP
Data Sheet
June 3, 2014
Depends on operating conditions.
Short circuit protection must be
enabled via Diag_cfg
(EEPROM word [102:100]).
See section 2.4.2.
Shorted input
2.2
mA
12
Bit
±0.2%
VDD
+3.0
LSB12Bit
VDD
16.5mV
mV
40
mA
5
±1LSB
mV
3
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
9 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
Parameter
1.3.6.
Symbol
Min
Typ
Max
Unit
Diagnostics
Upper diagnostic output level
VDIA,H
Lower diagnostic output level
VDIA,L
Minimum load resistor for power
2)
loss
1.3.7.
Conditions
RL,OUT_PS
97.5%
VDD
2.5%
Pull-up or pull-down in Analog
Output Mode
5
VDD
k
External Temperature Measurement
External Temperature (ExtTemp)
Signal Input Range
VTSE
150
800
mV
Required External Temperature
Diode Sensitivity
STTSE
1.9
3.25
mV/K
Temperature Span with External
Temperature Diode
TTSE_SP
-50
150
°C
3.9
kΩ
1
15
nF
0
0.2
VDD
1.3.8.
Parameters for ZACwire™ Serial Interface
™
ZACwire Line Resistance *
™
RZAC,load
ZACwire Load Capacitance *
CZAC,load
Voltage Level Low *
VZAC,low
Voltage Level High *
VZAC,low
1.3.9.
The rise time must be tZAC,rise =
2  RZAC,load  CZACload  5µs.
If using a pull-up resistor instead
of a line resistor, it must meet
this specification. The absolute
maximum for CZACload is 15nF.
0
0.8
1
VDD
Parameters for System Response
tSTA
Power-up to output
Update_rate = 1 kHz (1 ms)
Response Time – Analog Output
tRESP-A
Update_rate = 1 kHz (1 ms)
Response and Transmission
Time for Digital Output
tRES, DIG
Varies with update rate. Value
given at fastest rate.
Start-Up-Time
Sampling Rate
fS
1
8
ms
2
ms
1.6
ms
Update_rate = 1 kHz (1 ms)
1000
Hz
Overall Linearity Error– Digital
ELIND
Bridge input to output
0.025
0.04
%
Overall Linearity Error – Analog
ELINA
Bridge input to output
0.1
0.2
%
Overall Ratiometricity Error
REout
±10%VDD, Not using Bsink
feature
0.035
%
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
10 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
Parameter
Symbol
Overall Accuracy – Digital
(only IC, without sensor bridge)
ACoutD
3), 4)
Overall Accuracy – Analog
(only IC, without sensor bridge)
ACoutA
Conditions
Min
Typ
Max
Unit
-25°C to 85°C
0.1%
-50°C to 150°C
0.25%
-25°C to 85°C
0.25%
-40°C to 125°C
0.35%
-50°C to 150°C
0.5%
%FSO
%FSO
Note: This is  4 LSBs for the 14-bit A-to-D conversion. This results in absolute accuracy to 12-bits on the A-to-D result. Non-linearity is typically better at
temperatures less than 125°C.
When using a pull-down resistor as the load resistor, the power loss detection diagnostic for loss of VSS cannot be assured at R L=5kΩ; RL=10kΩ is
recommended for this configuration.
1)
2)
Not included is the quantization noise of the DAC. The 12-bit DAC has a quantization noise of  ½ LSB = 0.61mV (@ 5V VDD) = 0.0125%.
Analog output range 2.5% to 95%
3)
4)
1.4.
Analog Inputs versus Output Resolution
The ZSC31015 has a fully differential chopper-stabilized pre-amplifier with four programmable gain settings. The
output of the pre-amplifier feeds into a 14-bit charge-balanced ADC. Span, offset, temperature, and non-linearity
correction are performed in the digital domain. Then the resulting corrected bridge value can be output in analog
form through a 12-bit DAC or as a 16-bit serial digital packet. The resolution of the output depends on the input
span (bridge sensitivity) and the analog gain setting programmed. Digital gains can vary from [0,32). Analog gains
available are 6, 24, 48, and 96.
Note: At higher analog gain settings, there will be higher output resolution, but the ability of the ZSC31015 to
handle large offsets decreases. This is expected because the offset is also amplified by the analog gain and can
therefore saturate the ADC input.
The following tables outline the guaranteed minimum resolution for a given bridge sensitivity range.
Table 1.1
ADC Resolution Characteristics for an Analog Gain of 6
Analog Gain 6
Input Span [mV/V]
Min
1)
Typ
Max
Allowed Offset
1
(+/- % of Span)
Minimum Guaranteed
Resolution [Bits]
57.8
80.0
105.8
38%
12.4
50.6
70.0
92.6
53%
12.2
43.4
60.0
79.4
73%
12.0
36.1
50.0
66.1
101%
11.7
28.9
40.0
52.9
142%
11.4
21.7
30.0
39.7
212%
11.4
In addition to Tco, Tcg.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
11 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
Table 1.2
ADC Resolution Characteristics for an Analog Gain of 24
Analog Gain 24
Input Span [mV/V]
Min
1)
Typ
Max
Allowed Offset
1
(+/- % of Span)
Minimum Guaranteed
Resolution [Bits]
18.1
25.0
33.1
17%
12.7
14.5
20.0
26.5
38%
12.4
7.2
10.0
13.2
142%
11.4
3.6
5.0
6.6
351%
10.4
1.8
2.5
3.3
767%
9.4
0.9
1.2
1.6
1670%
8.4
In addition to Tco, Tcg.
Table 1.3
Important Note: The yellow shadowed fields indicate that for these input spans
with the selected analog gain setting, the quantization noise is higher than 0.1% FSO.
ADC Resolution Characteristics for an Analog Gain of 48
Analog Gain 48
Input Span [mV/V]
Min
1)
Typ
Max
Allowed Offset
1
(+/- % of Span)
Minimum Guaranteed
Resolution [Bits]
10.8
15.0
19.8
3%
13.0
7.2
10.0
13.2
38%
12.4
4.3
6.0
7.9
107%
11.7
2.9
4.0
5.3
194%
11.1
1.8
2.5
3.3
351%
10.4
1.0
1.4
1.85
678%
9.6
0.72
1.0
1.32
976%
9.1
In addition to Tco, Tcg.
Data Sheet
June 3, 2014
Important Note: The yellow shadowed fields indicate that for these input spans
with the selected analog gain setting, the quantization noise is higher than 0.1% FSO.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
12 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
Table 1.4
ADC Resolution Characteristics for an Analog Gain of 96
Analog Gain 96
Input Span [mV/V]
1)
Allowed Offset
1
(+/- % of Span)
Minimum Guaranteed
Resolution [Bits]
Min
Typ
Max
4.3
6.0
7.9
21%
12.7
2.9
4.0
5.3
64%
12.1
1.8
2.5
3.3
142%
11.4
1.0
1.4
1.85
306%
10.6
0.72
1.0
1.32
455%
10.1
In addition to Tco, Tcg.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
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ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
2
Circuit Description
2.1.
Signal Flow and Block Diagram
The ZSC31015 resistive bridge sensor interface ICs were specifically designed as cost-effective solutions for
sensing in building automation, automotive *, industrial, office automation and white goods applications. The
ZSC31015 employs ZMDI’s high precision bandgap with proportional-to-absolute-temperature (PTAT) output;
low-power 14-bit analog-to-digital converter (ADC, A2D, A-to-D); and an on-chip DSP core with EEPROM to
precisely calibrate the bridge output signal.
Three selectable outputs, two analog and one digital, offer the ultimate in versatility across many applications.
The ZSC31015 rail-to-rail ratiometric analog Vout signal (0V to ~5 V Vout @ VDD=5V) suits most building automation
and automotive requirements (12-bit resolution). Typical office automation and white goods applications require
the 0 to ~1V Vout signal, which in the ZSC31015 is referenced to the internal bandgap. The ZSC31015 is capable
of running in high-voltage (5.5 to 30V) systems when combined with an external JFET.
Direct interfacing to P controllers is facilitated via ZMDI’s single-wire serial ZACwire™ digital interface.
Figure 2.1 ZSC31015 Block Diagram
JFET1
(Optional if supply is 2.7 to 5.5 V)
S
0.1 F
VDD (2.7 to 5.5 V)
Sensor
Diagnostics
Temperature
Reference
VDD
Regulator
Ext Temp
Bsink
INMUX
PREAMP
Power Save
EEPROM
with Charge
Pump
POR/Oscillator
12-Bit
DAC
ZSC31015
A
VBN
(Optional)
Vgate
RBicdLite
PTAT
VBP
Optional
Ext. Diode
for Temp
5.5 V to 30 V
VSUPPLY
D
_
D
14-Bit ADC
Digital
Core
SIGTM
+
OUTBUF1
ZACwireTM
Interface
0 V to 1 V
Ratiometric
Rail-to-Rail
OWI/ZACwireTM
Power Lost
Diagnostic
Analog Block
VSS
Digital Block
*
Not AEC-Q100-qualified.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
14 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
2.2.
Analog Front End
2.2.1.
Bandgap/PTAT and PTAT Amplifier
The highly linear Bandgap/PTAT section provides the PTAT signal to the ADC, which allows accurate temperature conversion. In addition, the ultra-low ppm Bandgap provides a stable voltage reference over temperature for
the operation of the rest of the IC. If the bridge is not near the ZSC31015, an external diode can be used for
temperature measurement/compensation.
The temperature signal (internal PTAT or external diode) is amplified through a path in the Pre-Amp and fed to
the ADC for conversion. The most significant 12-bits of this converted result are used for temperature
measurement and temperature correction of bridge readings. When temperature is output in Digital Mode, only
the most significant 8 bits are given.
When external temperature is selected, add a diode from the ExtTemp pin to ground. The diode is biased with
approximately 50µA during temperature measurement cycles. The voltage level on ExtTemp is amplified through
the Pre-Amp and converted by the ADC. Ensure that the ExtTemp signal is in the range of 150mV to 800mV to
o
o
prevent saturation of the ADC. If the selected diode has a sensitivity in the range of 1.9mV/ C to 3.25mV/ C, a
o
o
o
corrected temperature output (in Digital Mode) can be achieved for a 200 C temperature span (-50 C to 150 C).
2.2.2.
Bridge Supply
The voltage-driven bridge is usually connected to VDD and ground. As a power savings feature, the ZSC31015
also includes a switched transistor to interrupt the bridge current via pin 1 (Bsink). The transistor switching is
synchronized to the analog-to-digital conversion and released after finishing the conversion. To utilize this feature,
the low supply of the bridge should be connected to Bsink instead of ground.
Depending on the programmable update rate, the average current consumption (including bridge current) can be
reduced to approximately 20%, 5%, or 1%. Note: this feature has no power savings benefit if using the fastest
update rate mode.
2.2.3.
PREAMP Block
The differential signal from the bridge is amplified through a chopper-stabilized instrumentation amplifier with very
high input impedance designed for low noise and low drift. This pre-amp provides gain for the differential signal
and re-centers its DC to VDD/2. The output of the Pre-Amp block is fed into the ADC. The calibration sequence
performed by the digital core includes an auto-zero sequence to null any drift in the Pre-Amp state over
temperature.
The Pre-Amp can be set to a gain of 6, 24, 48, or 96 through an EEPROM setting.
The inputs to the Pre-Amp from (VBN/VBP pins) can be reversed via an EEPROM configuration bit.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
15 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
2.2.4.
Analog-to-Digital Converter (ADC)
nd
A 14-bit/1ms 2 order charge-balancing ADC is used to convert signals coming from the pre-amplifier. The
converter, designed in full differential switched capacitor technique, is used for converting the various signals in
the digital domain.
This principle offers the following advantages:

High noise immunity because of the differential signal path and integrating behavior

Independence from clock frequency drift and clock jitter

Fast conversion time due to second-order mode
Four selectable values for the zero point of the input voltage allow conversion to adapt to the sensor’s offset
parameter. With the Reverse Input Polarity Mode and the negative digital gain options, this results in seven
possible zero point adjustments (not eight because the -1/2,1/2 offset setting is the same regardless of gain
polarity).
The conversion rate varies with the programmed update rate. The fastest conversation rate is 1k samples/s and
the response time is then 1ms. Based on a best fit, the Integral Nonlinearity (INL) is less than 4 LSB14Bit.
2.3.
Digital Signal Processor
A digital signal processor (DSP) is used for processing the converted bridge data as well as performing
temperature correction and computing the temperature value for output on the digital channel.
The digital core reads correction coefficients from EEPROM and can correct for the following:





Bridge Offset
Bridge Gain
Variation of Bridge Offset over Temperature (Tco)
Variation of Bridge Gain over Temperature (Tcg)
A single second order effect (SOT) (Second Order Term)
The EEPROM contains a single SOT that can be applied to correct one and only one of the following:
 2nd order behavior of bridge measurement
 2nd order behavior of Tco
 2nd order behavior of Tcg
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
16 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
If the SOT applies to correcting the bridge reading, then the correction formula for the bridge reading is
represented as a two-step process as follows:
ZB  Gain_ B(1 T  Tcg)  (BR _ Raw  Offset _ B  T  Tco)
(1)
BR  ZB(1.25  SOT  ZB)
(2)
Where:
Note
BR
=
Corrected Bridge reading that is output as digital or analog on the SIG
ZB
=
Intermediate result in the calculations
BR_Raw =
Raw Bridge reading from ADC
T_Raw
=
Raw Temp reading converted from PTAT signal or external diode
Gain_B
=
Bridge Gain term
TM
Offset_B =
Bridge Offset term
Tcg
=
Temperature Coefficient Gain
Tco
=
Temperature Coefficient Offset
T
=
(T_Raw – TSETL)
TSETL
=
T_Raw reading at which low calibration was performed (typically 25°C)
SOT
=
Second-Order Term
pin
For solving equation (1) the following condition must be met:
BR _ Raw  BR / Gain_ B
If this condition is not met, the analog Pre-Amp Gain must be set to a smaller value because a negative Offset_B
is not supported.
If the SOT applies to correcting the 2
nd
order behavior of Tco, then the formula for bridge correction is as follows:
BR  Gain_ B(1 T  Tcg)  [BR _ Raw  Offset _ B  T(SOT  T  Tco)]
If the SOT applies to correcting the 2
nd
(3)
order behavior of Tcg, then the formula for bridge correction is as follows:
BR  Gain_ B[1 T(SOT  T  Tcg)]  [BR _ Raw  Offset _ B  T  Tco]
(4)
The bandgap reference gives a very linear PTAT signal, so temperature correction can always simply be
accomplished with a linear gain and offset term.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
17 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
Corrected Temperature Reading:
T  Gain_ T(T _ Raw  Offset _ T)
(5)
Where:
T_Raw
2.3.1.
=
Raw Temperature reading converted from PTAT signal or external diode
Offset_T =
Offset Coefficient for Temperature
Gain_T
Gain Coefficient for Temperature
=
EEPROM
The EEPROM contains the calibration coefficients for gain and offset, etc., and the configuration bits, such as
output mode, update rate, etc. The ZSC31015 also offers three user-programmable storage bytes for module
traceability. When programming the EEPROM, an internal charge pump voltage is used; therefore a high voltage
supply is not needed. The EEPROM is implemented as a shift register. During an EEPROM read, the contents
are shifted 8 bits before each transmission of one byte occurs. The charge pump is internally regulated to 12.5 V,
and the programming time is 6ms.
See section 2.6.1 regarding EEPROM signatures for verifying EEPROM integrity.
Note: EEPROM writing can only be performed at temperatures lower than 85ºC.
2.3.2.
One-Wire Interface – ZACwire™
The IC communicates via a one-wire serial interface. There are different commands available for the following:

Reading the conversion result of the ADC (Get_BR_Raw, Get_T_Raw)

Calibration commands

Reading from the EEPROM (“dump” of entire contents)

Writing to the EEPROM (trim setting, configuration, and coefficients)
2.4.
Output Stage
2.4.1.
Digital to Analog Converter (Output DAC) with Programmable Clipping Limits
A 12-bit DAC based on sub-ranging resistor strings is used for the digital-to-analog output conversion in the
analog ratiometric and absolute analog voltage modes. Options during calibration configure the system to operate
in either of these modes. The design allows for excellent testability as well as low power consumption. The DAC
allows programming a lower and upper clipping limit (Low_Clip_Lim and Up_Clip_Lim bit fields respectively; see
section 3.5) for the output signal (analog and digital). The internal 14-bit calculated bridge value is compared
against the 14-bit value formed by {11,Up_Clip_Lim[6:0],11111} for the upper limit and against
{00,Low_Clip_Lim[6:0],00000} for the lower limit. If the calculated bridge value is higher than the upper limit or
less than the lower limit, the analog output value is clipped to this value; otherwise it is output as is.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
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ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
Example for the upper clipping level: If the Up_Clip_Lim[6:0] = 0000000, then the 14-bit value used for the
clipping threshold is 11000000011111. This is 75.19% of full scale. Since there are 7 bits of upper clipping limit,
there are 127 possible values between 75.19% and 100%. Therefore the resolution of the clipping limits 0.195%.
Example for the lower clipping level: If the Low_Clip_Lim[6:0] = 1111111, then the 14-bit value used for the
clipping threshold is 00111111100000. This is 24.8% of full scale. Since there are 7 bits of lower clipping limit,
there are 127 possible values between 0 and 24.8%. Therefore the resolution of the lower clipping limit is 0.195%.
Figure 2.2 shows the data timing of the DAC output for the update rate setting 00.
Figure 2.2 DAC Output Timing for Highest Update Rate
Settling Time
64 s
AD Conversion
768 s
Calculation
160 s
Settling Time
64 s
AD Conversion
768 s
Calculation
160 s
DAC output
occurs here
2.4.2.
DAC output
next update
Output Buffer
A rail-to-rail op amp configured as a unity gain buffer can drive resistive loads (whether pull-up or pull-down) as
low as 5k and capacitances up to 15nF (for pure analog output). In addition, to limit the error due to amplifier
offset voltage, an error compensation circuit is included which tracks and reduces offset voltage to < 1mV. The
output of the ZSC31015 output can be permanently shorted to VDD or VSS without damaging the device. The
output driver contains a current-limiting block that detects a hard short and limits the current to a safe level. The
short circuit protection current can vary from a minimum of 3mA to a maximum of 40mA depending on operating
conditions. Output short circuit protection can be enabled via Diag_cfg (EEPROM [102:100]). Enabling this
protection is recommended when using the analog output.
2.4.3.
Voltage Reference Block
A linear regulator control circuit is included in the Voltage Reference Block to interface with an external JFET to
allow operation in systems where the supply voltage exceeds 5.5V. This circuit can also be used for over-voltage
protection. The regulator set point has a coarse adjustment controlled by the JFET_cfg EEPROM bits that can
adjust the set point around 5.0 or 5.5V. (See Table 3.5 for bit locations and section 2.3.1 regarding writing to the
EEPROM.). The 1V trim setting (see below) can also act as a fine adjust for the regulation set point. The 5V
reference can be trimmed within +/-15mV.
Note: If using the external JFET for over-voltage protection purposes (i.e., 5V at JFET drain and expecting 5V at
JFET source), there will be a voltage drop across the JFET; therefore ratiometricity will be slightly compromised
depending on the rds(on) of the chosen JFET. A Vishay J107 is the best choice because it has only an 8mV drop
worst case. If using as regulation instead of over-voltage protection, a MMBF4392 or BSS169 also works well.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
19 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
The Voltage Reference Block uses the absolute reference voltage provided by the bandgap to produce two
regulated on-chip voltage references. A 1V reference is used for the output DAC high reference when the part is
configured in 0-1V Analog Output Mode. For this reason, the 1V reference must be very accurate and includes
trim so that its value can be trimmed within +/- 3mV of 1.00V. The 1V reference is also used as the on-chip
reference for the JFET regulator block. The regulation set point of the JFET regulator can be fine-tuned using the
1V trim.
The reference trim setting is selected with the 1V_Trim/JFET_Trim bits in EEPROM. See Table 3.5 for bit
locations. Table 2.1 shows the order of trim codes with 0111 for the lowest reference voltage and 1000 for the
highest reference voltage.
Important: Optimal reference trim is determined during wafer-level testing and final package testing. Back-up
copies of these bits are stored in bits in the CUST_ID0 bits for applications requiring accurate references. In this
case, see section 5 for important notes and instructions for verifying the integrity of the 1V_Trim/JFET_Trim bits
and if necessary, restoring the value from the CUST_ID0 bits before calibration.
Table 2.1
1V Reference Trim (1V vs. Trim for Nominal Process Run)
1Vref/
5Vref_trim3
1Vref/
5Vref_trim2
1Vref/
5Vref_trim1
1Vref/
5Vref_trim0
Highest Reference Voltage
1
0
0
0
…
1
0
0
1
…
1
0
1
0
…
1
0
1
1
…
1
1
0
0
…
1
1
0
1
…
1
1
1
0
…
1
1
1
1
…
0
0
0
0
…
0
0
0
1
…
0
0
1
0
…
0
0
1
1
…
0
1
0
0
…
0
1
0
1
…
0
1
1
0
Lowest Reference Voltage
0
1
1
1
Order
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
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ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
2.5.
Clock Generator / Power-On Reset (CLKPOR)
If the power supply exceeds 2.5V (maximum), the reset signal de-asserts and the clock generator starts working
at a frequency of approximately 512kHz (±20%). The exact value only influences the conversion cycle time and
communication to the outside world but not the accuracy of signal processing. In addition, to minimize the
oscillator error as the VDD voltage changes, an on-chip regulator is used to supply the oscillator block.
2.5.1.
Trimming the Oscillator
Settings for the Osc_Trim bits in EEPROM fine-tune the oscillator frequency. See Table 3.5 for bit locations and
Table 2.2 for possible settings. The default value is 0HEX to ensure communication on start-up.
Important: Optimal oscillator trimming is determined during wafer-level testing and final package testing, and this
part-specific factory value, which can be copied to Osc_Trim, is stored in bits in the CUST_ID1 and CUST_ID2
EEPROM bits for applications requiring optimal response time. In this case, see section 5 for important notes and
instructions for copying these optimal values to the Osc_Trim bits before calibration. It is strongly recommended
TM
that only the default value or the factory trim value be used because ZACwire communication is not guaranteed
at different oscillator frequencies.
Table 2.2
Oscillator Trimming
Osc_Trim Bits
Delta Frequency (kHz)
100
+385
101
+235
110
+140
111
+65
000
Nominal
001
-40
010
-76
011
-110
Example: Programming 011B  the trimmed frequency = nominal value – 110 kHz.
2.6. Diagnostic Features
The ZSC31015 offers a full suite of diagnostic features to ensure robust system operation in the most “missioncritical” applications. If the part is programmed in Analog Output Mode, then diagnostic states are indicated by
an output below 2.5% of VDD or above 97.5% of VDD. If the part is programmed in Digital Output Mode, then
diagnostic states will be indicated by a transmission with a generated parity error.
Table 2.3 gives a summary of the diagnostic features, which are explained in detail in the following sections.
EEPROM settings that control diagnostic functions are given in section 3.5.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
21 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
Table 2.3
Summary of Diagnostic Features
Analog
Diagnostic Level
Detected Fault
TM
ZACwire
Diagnostic
Delay in Detection
EEPROM signature
Lower
Generates parity error
Loss of bridge positive
Upper
Generates parity error
2ms
Loss of bridge negative
Upper
Generates parity error
2ms
Open bridge connection
Upper
Generates parity error
2ms
Bridge input short
Upper
Generates parity error
2ms
ExtTemp pin open
Lower
Generates parity error
300ms
Lower
Generates parity error
300ms
ExtTemp pin shorted to BP/BN
Upper
Generates parity error
3ms
Loss of VDD
Lower
Transmissions stop
Dependent on RL and CL
Loss of VSS
Upper
Transmissions stop
Dependent on RL and CL
ExtTemp pin shorted to PWR/GND
†
2.6.1.
10ms after power-on
EEPROM Integrity
The contents of the EEPROM are protected by an 8-bit LFSR signature (linear feedback shift register). This signature is regenerated and stored in EEPROM every time EEPROM contents are changed. This signature is generated and checked for a match after Power-On-Reset prior to entering Normal Operation Mode. If the generated
signature fails to match, the part will output a diagnostic state on the output.
In addition to an extensive temporal and code interlock mechanism used to prevent false writes to the EEPROM,
the ZSC31015 offers an EEPROM lock mechanism for high-security applications. When EEPROM bits 105:103
are programmed with “011” or “110,” this 3-bit field will permanently disable the VPP charge pump and will not
allow further writes to the EEPROM. See Table 2.3 in section 2.6 for more information.
2.6.2.
Sensor Connection Check
Four dedicated comparators permanently check the range of the bridge inputs (BP/BN) to ensure they are within
the envelope of 0.8V to 0.85VDD during all conversions. The two sensor inputs have a switched ohmic path to
ground and if left floating, would be discharged. If any of the wires connecting the bridge break, this mechanism
will detect it and put the ZSC31015 in a diagnostic state. This same diagnostic feature can also detect a short
between BP/BN and the ExtTemp signal if an external diode is being used for temperature measurement. See
Table 2.3 in section 2.6 for more information.
†
A short from ExtTemp to BP/BN might not be detected in some circuit configurations.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
22 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
2.6.3.
Sensor Short Check
If a short occurs between BP/BN (bridge inputs), it would normally produce an in-range output signal and therefore would not be detected as a fault. This diagnostic mode, if enabled, will deliberately look for such a short. After
the measurement cycle of the bridge, it will deliberately pull the BP bridge input to ground for 4sec. At the end of
this 4sec window, it will check to see if the BN input “followed” it down below the 0.8V comparator checkpoint. If
so, a short must exist between BP/BN, and the part will output a diagnostic state. The bridge will have a minimum
of 480sec recovery time prior to the next measurement. See Table 2.3 in section 2.6 for more information.
The bridge resistance must be taken into account if the Sensor Short diagnostic feature is used. At VDD= 2.7V, the
minimum bridge resistance is 0.3Kand at VDD = 5V, the minimum bridge resistance is 0.6K.
2.6.4.
Power Loss Detection
If the power or GND connection to the module containing the sensor bridge and the ZSC31015 is lost, the
ZSC31015 will output a diagnostic state if a pull-up or pull-down terminating resistor greater than or equal to 5k
is connected in the final application. This diagnostic mode only works when the part is configured in Analog
Output Mode. See Table 2.3 in section 2.6 for more information.
2.6.5.
ExtTemp Connection Checks
When external temperature is selected and connection checking is enabled, the part performs range checking on
the converted temperature value. If the internal ADC reading of the temperature is less than 1/32 of full scale or
greater than 63/64 of full scale then a diagnostic state is asserted. If the ExtTemp pin is shorted to ground, the
ADC reads less than 1/32. Because 100µA is sourced onto the ExtTemp pin during conversions, it naturally pulls
up during these times. If the ExtTemp pin is open, it produces an ADC reading greater than 63/64 of full scale.
Both these bad connection conditions would be detected and result in a diagnostic output. If internal temperature
is selected or sensor connection check is not enabled, then this diagnostic check is not enabled. See Table 2.3 in
section 2.6 for more information.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
23 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
3
Functional Description
3.1.
General Working Mode
The command/data transfer takes place via the one-wire SIG™ pin using the ZACwire
protocol.
TM
serial communication
After power-on, the ZSC31015 waits for 3ms (= Command window) for the Start_CM command.
Without this command, the Normal Operation Mode (NOM) starts. In this mode, raw bridge values are converted,
and the corrected values are presented on the output in analog or digital format (depending on the configuration
stored in EEPROM).
Command Mode (CM) can only be entered during the 3ms command window after power-on. If the ZSC31015
receives the Start_CM command during the command window, it remains in the Command Mode. The CM allows
changing to one of the other modes via command. After the command Start_RW, the ZSC31015 is in the Raw
Mode (RM). Without correction, the raw values are transmitted to the digital output in a predefined order. The RM
can only be stopped by a power-off. RM is used by the calibration software for collection of raw bridge and
temperature data so the correction coefficients can be calculated.
If diagnostic features are enabled and a diagnostic fault is detected, diagnostic states are indicated as follows
depending on the programmed mode:


In Analog Output Mode,
diagnostic states are indicated by an output below 2.5% of VDD or above 97.5% of VDD.
In Digital Output Mode,
diagnostic states will be indicated by a transmission with a generated parity error.
For more details see section 2.6.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
24 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
Figure 3.1 General Working Mode
Power ON
Command
Window (3 ms); send
Start_CM
Start_CM
No Command
Normal Operation Mode
Start_NOM
Command Mode
Start_RM
Raw Mode
No commands possible
Measurement cycle stopped
Measurement cycle
Measurement cycle
Full command set
SigTM pin provides raw bridge
and temperature values in the
format:
• Bridge_high (1st byte)
• Bridge_low
(2nd byte)
• Temp
(3rd byte)
Conditioning calculations
(corrected bridge and
temperature values)
Command routine will be
processed after each
command
Depending on configuration,
the SigTM pin is
• 0 V to 1 V;
• Rail-to-rail ratiometric; or
• Digital output
Diagnostic functions
Power OFF
Error Detection
Diagnostic
State*
* See section 2.6.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
25 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
3.2.
ZACwire™ Communication Interface
3.2.1.
Properties and Parameters
Table 3.1
No.
Pin Configuration and Latch-Up Conditions
Parameter
Symbol
1
Pull-up resistor (on-chip)
RZAC,pu
2
Pull-up resistor (external)
RZAC,pu_ext
3
ZACwire™ rise time
4
ZACwire™ line resistance
1)
1)
Typ
Max
30
150
Unit
Comments
kΩ
On-chip pull-up resistor switched on
during Digital Output Mode and during
CM Mode (first 3 ms after power up).
Ω
If the master communicates via a pushpull stage, no pull-up resistor is needed;
otherwise, a pull-up resistor with a value
of at least 150 Ω must be connected.
tZAC,rise
5
µs
Any user RC network included in the
Sig™ path must meet this rise time.
RZACload
3.9
kΩ
Also see section 1.3.8.
1
15
nF
Also see section 1.3.8.
0
0.2
VDD
Rail-to-rail CMOS driver.
VDD
Rail-to-rail CMOS driver.
5
ZACwire™ load capacitance
6
Voltage low level
VZAC,low
7
Voltage high level
VZAC,high
1)
Min
CZAC,load
0
0.8
1
The rise time must be tZAC,rise = 2  RZACload  CZACload  5 s . If using a pull-up resistor instead of a line resistor, it must meet this
specification. The absolute maximum for CZACload is 15nF.
3.2.2. Bit Encoding
Figure 3.2 Manchester Duty Cycle
Bit Window
104.2µsec @ 9.6 kHz baud
40 µsec @ 26kHz baud
Start Bit
Start bit = 50% duty cycle used to set up strobe time
Logic 1
Logic 1 = 75% duty cycle
Logic 0
Logic 0 = 25% duty cycle
Stop Time
The ZACWire™ bus will be held high for 32μs (nominal)
between consecutive data packets regardless of baud rate.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
26 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
3.2.3.
Write Operation from Master to ZSC31015
The calibration master sends a 19-bit packet frame to the IC.
Figure 3.3 19-Bit Write Frame
19-bit Frame (WRITE)
S 7 6 5 4 3 2 1 0 P 7 6 5 4 3 2 1 0 P
Command Byte
Data Byte
S Start Bit
P Parity Bit of Command or Data Byte
2 Command Bit (example: Bit 2)
2 Data Bit (example: Bit 2)
The incoming serial signal will be sampled at a 512 kHz clock rate. This protocol is very tolerant to clock skew,
and can easily tolerate baud rates in the 6 kHz to 48 kHz range.
3.2.4.
ZSC31015 Read Operations
The incoming frame will be checked for proper parity on both, command and data bytes, as well as for any edge
time-outs prior to a full frame being received.
Once a command/data pair is received, the ZSC31015 will perform that command. After the command has been
successfully executed by the ZSC31015, it will acknowledge success by a transmission of an A5 HEX-byte back to
the master. If the master does not receive an A5 HEX transmission within 130 ms of issuing the command, it must
assume the command was either improperly received or could not be executed.
Figure 3.4 Read Acknowledge
1 DATA Byte Packet
(10-bit byte A5H)
S Start Bit
S 1 0 1 0 0 1 0 1 P
P Parity Bit of Data Byte
Data Byte
0 Data Bit (Low)
1 Data Bit (High)
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
27 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
The ZSC31015 transmits 10-bit bytes (1 start bit, 8 data bits, 1 parity bit). During calibration and configuration,
transmissions are normally either A5HEX or data. A5HEX indicates successful completion of a command. There are
two different digital output modes configurable (digital output with temperature, and digital output with only bridge
data). During Normal Operation Mode, if the part is configured for digital output of the bridge reading, it first
transmits the high byte of bridge data, followed by the low byte. The bridge data is 14 bits in resolution, so the
upper two bits of the high byte are always zero-padded. There is a half stop bit time between bytes in a packet.
This means that for the time of a half a bit width, the signal level is high.
Figure 3.5 Digital Output (NOM) Bridge Readings
2 DATA Byte Packet
(Digital Bridge Output )
S Start Bit
S 0 0 5 4 3 2 1 0 P Stop S 7 6 5 4 3 2 1 0 P
Data Byte
Bridge High
Data Byte
Bridge Low
P Parity Bit of Data Byte
2 Data Bit (example: Bit 2)
Stop
32µs
The second option for Digital Output Mode is digital output bridge reading with temperature. It will be transmitted
as 3 data packets. The temperature byte represents an 8-bit temperature quantity spanning from -50 to 150°C.
Figure 3.6 Digital Output (NOM) Bridge Readings with Temperature
3 DATA Byte Packet
(Digital Bridge Output with Temperature )
S 0 0 5 4 3 2 1 0 P Stop S 7 6 5 4 3 2 1 0 P Stop S 7 6 5 4 3 2 1 0 P
Data Byte
Bridge High
Data Byte
Bridge Low
Data Byte
Temperature
The EEPROM transmission occurs in a packet with 20 data bytes, as shown in Figure 3.7.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
28 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
Figure 3.7 Read EEPROM Contents
20 DATA Byte Packet
(Read EEPROM)
S 7 6 5 4 3 2 1 0 P Stop S 7 6 5 4 3
EEPROM
Byte 1
EEPROM
Byte 2
...
5 4 3 2 1 0 P Stop S 7 6 5 4 3 2 1 0 P Stop S 1 0 1 0 0 1 0 1 P
EEPROM
Byte 18
EEPROM
Byte 19
Data Byte A5H
There is a variable idle time between packets. This idle time varies with the update rate setting in EEPROM.
Figure 3.8 Transmission of a Number of Data Packets
Packet Transmission
(This example shows 2 DATA packets)
210P
IDLE
IDLE
IDLE
S 0 0 5 4 3 2 1 0 PStop S 7 6 5 4 3 2 1 0 P
S 0 0 5 4 3 2 1 0 PStop S 7 6 5 4 3 2 1 0 P
S0054
Time
Time
Time
The table below shows the idle time between packets versus the update rate. This idle time can vary by nominal
+/-15% between parts and over a temperature range of -50 to 150ºC.
Table 3.2
Special Measurement/Idle Time between Packets versus Update Rate
Update Rate Setting
Idle Time between Packets
Special Measurement
00
1ms
Every 128 bridge measurements
01
4.85ms
Every 64 bridge measurements
10
22.5ms
Every 16 bridge measurements
11
118ms
Every 8 bridge measurements
Transmissions from the IC occur at one of two speeds depending on the update rate programmed in EEPROM. If
the user chooses one of the two fastest update rates (1 ms or 5 ms) then the baud rate of the digital transmission
will be 32 kHz (minimum 26kHz). If, however, the user chooses one of the two slower update rates (25 ms or
125 ms), then the baud rate of the digital transmission will be 8 kHz (maximum 9.6kHz).
The total transmission time for both digital output configurations is shown in Table 3.3.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
29 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
Table 3.3
Total Transmission Time for Different Update Rate Settings and Output Configuration
Update Rate
Baud Rate*
Idle Time
Transmission Time –
Bridge Only Readings
Transmission Time –
Bridge & Temperature Readings
1 ms (1 kHz)
32 kHz
1.0 ms
20.5 bits
31.30 µs
1.64 ms
31.0 bits
31.30 µs
1.97 ms
5 ms (200 Hz)
32 kHz
4.85 ms
20.5 bits
31.30 µs
5.49 ms
31.0 bits
31.30 µs
5.82 ms
25 ms (40 Hz)
8 kHz
22.5 ms
20.5 bits
125.00 µs
25.06 ms
31.0 bits
125.00 µs
26.38 ms
125 ms (8 Hz)
8 kHz
118.0 ms
20.5 bits
125.00 µs
120.56 ms
31.0 bits
125.00 µs
121.88 ms
* Typical values. Minimum baud rate for 1 ms or 5 ms: 26kHz; maximum baud rate for 25 ms or 125 ms: 9.6kHz.
The temperature raw reading is performed less often than a bridge reading because the temperature changes
more slowly.
rd
The 3 column in Table 3.2 shows the timing for the special measurements (temperature and bridge
measurement) in the different update rate modes.
For lower update rates, the output is followed by a power-down as shown in Figure 3.9.
Figure 3.9 ZACwire™ Output Timing for Lower Update Rates
Calculation
160 s
ZACwireTM
Output
Power Down
(determined by
Update Rate)
Power-On
Settling
128 s
Settling Time
64 s
ADC Conversion
768 s
Calculation
160 s
ZACwireTM
Output
It is easy to program any standard microcontroller to communicate with the ZSC31015. ZMDI can provide sample
code for a MicroChip PIC microcontroller.
3.2.5.
High Level Protocol
The ZSC31015 will listen for a command/data pair to be transmitted for the 3 ms after the de-assertion of its
internal Power On Reset (POR). If a transmission is not received within this time frame, then it will transition to
Normal Operation Mode (NOM). In the NOM, it will output bridge data in 0-1V analog, rail-to-rail ratiometric
analog, or digital depending on how the part is currently configured.
If the ZSC31015 receives a Start_CM command within the first 3 ms after the de-assertion of POR, then it will go
into Command Mode (CM). In this mode, calibration/configuration commands will be executed. The ZSC31015
will acknowledge successful execution of commands by transmission of A5 HEX. The calibrating /configuring master
will know a command was not successfully executed if no response is received after 130ms of issuing the
command. Once in command interpreting/executing mode, the ZSC31015 will stay in this mode until power is
removed or a Start NOM (Start Normal Operation Mode) command is received. The Start_CM command is used
as an interlock mechanism to prevent a spurious entry into Command Mode on power up. The first command
received within the 3ms window of POR must be a Start_CM command to enter into command interpreting mode.
Any other commands will be ignored.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
30 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
3.3.
Command/Data Bytes Encoding
The 2-byte command sent to the ZSC31015 consists of 1 byte of command information and 1 byte of data
information. Regardless of whether the command requires data or not, 2 bytes MUST be sent. Table 3.4 lists all
the command/data pairings. (X=don’t care.)
Table 3.4
Command/Data Bytes Encoding
Note: Refer to Table 3.5 for the location in EEPROM for the bit fields (e.g., Gain_B) referenced in the table.
Command
Byte
Data
Description
00HEX
XXHEX
Read EEPROM command via SIG™ pin.
20HEX
5XHEX
DAC Ramp Test Mode. Gain_B[13:3] contains the starting point, and the increment is
(Offset_B/8). The increment will be added every 125µsec.
30HEX
WDHEX
Trim/Configure: 3 nibble determines what is trimmed/configured. The 4 nibble is data to be
programmed.
‡
rd
rd
th
3 Nibble
4 Nibble Data
W=
What
0HEX
DHEX
Trim oscillator. Least significant 3 bits of data used.
1HEX
DHEX
Trim 1V reference. Least significant 4 bits of data used.
D=
Data
2HEX
DHEX
Offset Mode. Least significant 4 bits of data used.
3HEX
DHEX
Set output mode. Least significant 2 bits used.
4HEX
DHEX
Set update rate. Least significant 2 bits used.
5HEX
DHEX
Configure JFET regulation
6HEX
DHEX
Program the Tc_cfg register. Least significant 3 bits used.
Most significant bit of data nibble should be 0.
7HEX
DHEX
Program EEPROM bits [99:96] {SOT_cfg,Pamp_Gain}
DHEX
3HEX
0HEX,1HEX,2HEX
6HEX
4HEX,5HEX,7HEX
EHEX
‡
§
th
DHEX
Description
Program EEPROM bits [105:103]:
EEPROM locked! Int. PTAT used for temperature
EEPROM unlocked, Int. PTAT used for temperature
EEPROM locked! Ext. diode used for temperature
EEPROM unlocked, Ext. diode used for temperature
Program EEPROM bits [102:100] diag_cfg
§
40HEX
00HEX
Start NOM => Ends Command Mode; transition to Normal Operation Mode.
40HEX
10HEX
Start_RM = Start the Raw Mode (RM)
In this mode, if Gain_B = 800HEX and Gain_T = 80HEX, then the digital output will simply be the
raw values of the ADC for the Bridge reading, and the PTAT conversion.
50HEX
90HEX
Start_CM => Start the Command Mode; used to enter Command Interpret Mode.
60HEX
YYHEX
Program SOT (2
nd
Order Term)
For more details, refer to section 3.7.
For more details, refer to section 3.5.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
31 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
Command
Byte
Data
Description
70HEX
YYHEX
Program TSETL (Set the MSB to 0.)
80HEX
YYHEX
Program Gain_B upper 7-bits (Set the MSB to 0.)
90HEX
YYHEX
Program Gain_B lower 8-bits
A0HEX
YYHEX
Program Offset_B upper 6-bits (Set the two MSBs to 0.)
B0HEX
YYHEX
Program Offset_B lower 8-bits
C0HEX
YYHEX
Program Gain_T
D0HEX
YYHEX
Program Offset_T
E0HEX
YYHEX
Program Tco
F0HEX
YYHEX
Program Tcg
08HEX
YYHEX
Program Upper Clipping Limit (Set the MSB to 0.)
18HEX
YYHEX
Program Lower Clipping Limit (Set the MSB to 0.)
28HEX
YYHEX
Program Cust_ID0
38HEX
YYHEX
Program Cust_ID1
48HEX
YYHEX
Program Cust_ID2
3.4.
Calibration Sequence
Although the ZSC31015 can work with many different types of resistive bridges, assume a pressure bridge is
being used for the following discussion on calibration.
Calibration essentially involves collecting raw bridge and temperature data from the ZSC31015 for different known
pressures and temperatures. This raw data can then be processed by the calibration master (typically a PC) to
compute the coefficients, and the calculated coefficients can then be written to the ZSC31015.
ZMDI can provide software and hardware with samples to perform the calibration.
There are three main steps to calibration:
1.
Assigning a unique identification to the ZSC31015. This identification is programmed in EEPROM and
can be used as an index into the database stored on the calibration PC. This database will contain all the
raw values of bridge readings and temperature readings for that part, as well as the known pressure (for
this application) and temperature the bridge was exposed to. This unique identification can be stored in a
concatenation of the following EEPROM registers: Cust_ID0, Cust_ID1, Cust_ID2. These registers can
also form a permanent serial number.
2. Data collection. Data collection involves getting raw data from the bridge at different known pressures and
temperatures. This data is then stored on the calibration PC using the unique identification of the
ZSC31015 as the index to the database.
3. Coefficient calculation and write. Once enough data points have been collected to calculate all the
desired coefficients then the coefficients can be calculated by the calibrating PC and written to the
ZSC31015.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
32 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
Step 1 – Assigning Unique Identification
Assigning a unique identification number is as simple as using the commands Program Cust_ID0, Program
Cust_ID1 and Program Cust_ID2. These three 8-bit registers allow for more than 16 million unique devices.
Gain_B must be programmed to 800HEX (unity) and Gain_T must be programmed to 80HEX (unity).
Step 2 – Data Collection
The number of unique (pressure, temperature) points that calibration must be performed at depends on the user’s
needs. The minimum is a 2-point calibration, and the maximum is a 5-point calibration. To acquire raw data from
the part, set the ZSC31015 to enter Raw Mode. This is done by issuing a Start_CM (Start Command Mode
5090HEX) command/data pair to the ZSC31015 followed by a Start_RM (Start Raw Mode 4010HEX) command/data
pair with the LSB of the upper data nibble set. Now if the Gain_B term has been set to unity (800 HEX) and the
Gain_T term has also been set to unity (80HEX), then the part will be in the Raw Mode and will output raw data on
TM
its SIG pin instead of corrected bridge and temperature. Capture several of these data points with the user’s
calibration system (16 each of bridge and temperature is recommended) and average them. Store these raw
bridge and temperature settings in the database along with the known pressure and temperature.
The output format during Raw Mode is Bridge_High, Bridge_Low, Temp. Each of these is an 8-bit quantity. The
upper 2-bits of Bridge_High are zero-filled. The Temp data (8-bits only) would not be enough information for
accurate temperature calibration. Therefore the upper three bits of temperature information are not given, but
rather assumed known. Therefore effectively 11-bits of temperature information are provided in this mode.
Step 3 – Coefficient Calculations
The math to perform the coefficient calculation is very complicated and will not be discussed in detail. There is a
rough overview in section 3.6. ZMDI will provide software to perform the coefficient calculation. ZMDI can also
provide source code for the algorithms in a C code format. After the coefficients are calculated, the final step is to
write them to the EEPROM of the ZSC31015.
The number of calibration points required can be as few as two or as many as five. This depends on the precision
desired and the behavior of the resistive bridge in use.
1. 2-point calibration can be used if only a gain and offset term are needed for a bridge with no temperature
compensation for either term.
st
2. 3-point calibration would be used to obtain 1 order compensation for either a Tco or Tcg term but not
both.
nd
3. 3-point calibration could also be used to obtain 2 order correction for the bridge but no temperature
compensation of the bridge output.
st
4. 4-point calibration would be used to obtain 1 order compensation for both Tco and Tcg.
st
nd
5. 4-point calibration could also be used to obtain 1 order compensation for Tco and a 2 order correction
for the bridge measurement.
st
st
6. 5-point calibration would be used to obtain both 1 order Tco correction and 1 order Tcg correction, plus
nd
nd
nd
a 2 order correction that could be applied to one and only one of the following: 2 order Tco, 2 order
nd
Tcg, or 2 order bridge.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
33 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
3.5.
EEPROM Bits
Table 3.5 shows the bit order and default settings for the EEPROM, which are programmed through the serial
interface. See section 5 for important information for die/wafer customers.
Table 3.5
EEPROM
Range
2:0
ZSC31015 EEPROM Bits
Description
Osc_Trim
Default
Settings
As of ww08/2009
Notes
0HEX
See section 2.5 for details on oscillator trim.
This default setting
minimizes risk of
communication
failure on start-up.
100 => Fastest
101 => 3 clicks faster than nominal
110 => 2 clicks faster than nominal
111 => 1 click faster than nominal
000 => Nominal
001 => 1 click slower than nominal
010 => 2 clicks slower than nominal
011 => Slowest
(Actual part-specific
factory values for
Osc_Trim are
initially stored in bits
in CUST_ID1 and
CUST_ID2 for applications requiring optimal response time.
See section 5 for
important notes.)
6:3
1V_Trim/JFET_Trim
ssssBIN
See Table 2.1 in the “Voltage Reference Block” section.
where “s” is the partspecific factory bit
setting for the
reference voltage
trim value.
(Back-up copies are
stored in CUST_ID0
for applications requiring accurate
references. See
section 5 for important notes.)
10:7
Data Sheet
June 3, 2014
A2D_Offset
3HEX
The upper two bits are flip polarity and invert bridge input
(negative gain) respectively. If both are used in conjunction,
negative offset modes can be achieved.
00 => normal polarity, positive gain
01 => normal polarity, negative gain
10 => flip polarity, positive gain
11 => flip polarity, negative gain
The lower two bits form the ADC offset selection.
Offset selection:
11 => [-1/2,1/2] mode bridge inputs
10 => [-1/4,3/4] mode bridge inputs
01 => [-1/8,7/8] mode bridge inputs
00 => [-1/16,15/16] mode bridge inputs
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
34 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
EEPROM
Range
Description
Default
Settings
As of ww08/2009
Notes
12:11
Output_Select
2HEX
00 => Digital (3 bytes with parity)
Bridge High {00,[5:0]}
Bridge Low [7:0]
Temp [7:0]
01 => 0-1V Analog
10 => Rail-to-Rail Ratiometric
11 => Digital (2 bytes with parity) (No Temp)
Bridge High {00,[5:0]}
Bridge Low [7:0]
14:13
Update_Rate
2HEX
00 => 1 msec (1kHz)
01 => 5 msec (200Hz)
10 => 25 msec (40Hz)
11 => 125 msec (8 Hz)
16:15
JFET_cfg
3HEX
00 => No JFET regulation (lower power)
01 => No JFET regulation (lower power)
10 => JFET regulation centered around 5.0V
11 => JFET regulation centered around 5.5V (i.e., over-voltage
protection)
31:17
Gain_B
198HEX
Bridge Gain (also see bits 10:7):
Gain_B[14] => multiply x 8
Gain_B[13:0] => 14-bit unsigned number representing a
number in the range [0,8)
45:32
Offset_B
0HEX
Unsigned 14-bit offset for bridge correction
53:46
Gain_T
80HEX
Temperature gain coefficient used to correct PTAT
or ExtTemp reading
61:54
Offset_T
0HEX
Temperature offset coefficient used to correct PTAT
or ExtTemp reading
68:62
TSETL
0HEX
Stores Raw PTAT or ExtTemp reading at temperature in which
low calibration points were taken
76:69
Tcg
0HEX
Coefficient for temperature correction of bridge gain term:
Tcg = 8-bit magnitude of Tcg term. Sign is determined by Tc_cfg
(bits 87:85).
84:77
Tco
0HEX
Coefficient for temperature correction of bridge offset term.
Tco = 8-bit magnitude of Tco term. Sign and scaling are
determined by Tc_cfg (bits 87:85)
87:85
Tc_cfg
0HEX
This 3-bit term determines options for temperature compensation
of the bridge.
Tc_cfg[2] => If set, Tcg is negative
Tc_cfg[1] => Scale magnitude of Tco term by 8, and if SOT
applies to Tco, scale SOT by 8
Tc_cfg[0] => If set, Tco is negative
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
35 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
EEPROM
Range
Description
Default
Settings
As of ww08/2009
Notes
nd
95:88
SOT
0HEX
2 Order Term. This term is a 7-bit magnitude with sign.
SOT[7] = 1  negative
SOT[7] = 0  positive
SOT[6:0] = magnitude [0-127]
nd
This term can apply to a 2 order Tcg, Tco or bridge correction.
(See Tc_cfg above.)
99:96
{SOT_cfg,
Pamp_Gain}
5HEX
Bits [99:98] = SOT_cfg
00 = SOT applies to Bridge
01 = SOT applies to Tcg
10 = SOT applies to Tco
11 = Prohibited
Bits [97:96] = Pre-Amp Gain
00 => 6
01 => 24 (default setting)
10 => 48
11 => 96
102:100
Diag_cfg
7HEX
This 3-bit term applies to diagnostic features
Diag_cfg[2]  enable output short circuit protection.
Diag _cfg[1]  enable sensor short checking.
Diag_cfg[0]  enables sensor connection checking.
105:103
Lock_ExtTemp
0HEX
EEPROM lock
011 or 110 => locked
All other
=> unlocked
When EEPROM is locked, the internal charge pump is disabled
and the EEPROM can never be programmed again.
Bit 105 (the MSB of this field) is also used for selecting external
temperature measurement.
000,001,010,011=>Internal PTAT used for temp
100,101,110,111=>External diode used for temp
112:106
Up_Clip_Lim
7FHEX
7-bit value used to select an upper clipping limit for the output. It
affects both analog and digital output. The 14-bit upper clipping
limit value is comprised of {11,Up_Clip_Lim[6:0],11111}. 127
different clipping levels are selectable between 75.19% and
100% of VDD.
119:113
Low_Clip_Lim
0HEX
7-bit value used to select a lower clipping limit for the output. It
affects both analog and digital output. The 14-bit lower clipping
limit value is comprised of {00,Low_Clip_Lim[6:0],00000}. 127
different clipping levels are selectable between 0% and 24.8%
of VDD.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
36 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
EEPROM
Range
127:120
Description
Cust_ID0
Default
Settings
As of ww08/2009
ssBIN
where “s” is a partspecific factory bit
setting.
During factory testing, two back-up
copies of the optimal
setting for the
1V_Trim/JFET_Trim
bits are stored in
[123:120] and in
[127:124]. See important notes in
section 5.
135:128
Cust_ID1
xsss xsssBIN
where “s” is a partspecific factory bit
setting and x is
“don’t care.”
During factory testing, two copies of
the optimal setting
for the Osc_Trim
bits are stored in
[130:128] and in
[134:132]. (Also in
Cust_ID2.) See important notes in
section 5.
143:136
Cust_ID2
xxxx xsssBIN
where “s” is a partspecific factory bit
setting and X is
“don’t care.”
During factory testing, a copy of the
optimal setting for
the Osc_Trim bits is
stored in [138:136].
(Also in Cust_ID1.)
See important notes
in section 5.
151:144
**
Signature
Notes
Customer ID byte 0
Can be used to store a customer part identification number.
Caution: If the application requires accurate voltage references,
do not overwrite this byte until completing the procedures in
section 5.
Customer ID byte 1
Can be used to store a customer part identification number.
Caution: If the application requires optimal response time, do not
overwrite this byte until completing the procedures in section 5.
Customer ID byte 2
Can be used to store a customer part identification number.
Caution: If the application requires optimal response time, do not
overwrite this byte until completing the procedures in section 5.
**
8-bit EEPROM signature. Generated through a LFSR . This
signature is checked on power-on to ensure integrity of EEPROM
contents.
Linear feedback shift register
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
37 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
3.6.
Calibration Math
3.6.1.
Correction Coefficients
All terms are calculated external to the ZSC31015 and then programmed to the EEPROM through the serial
interface.
Table 3.6
Correction Coefficients
Coefficient
Gain_B
Offset_B
Gain_T
Offset_T
Description
Gain term used to compensate span of Bridge reading
Offset term used to compensate offset of Bridge reading
Gain term used to compensate span of Temp reading
Offset term used to compensate offset of Temp reading
SOT
Second Order Term. The SOT can be applied as a second order correction term for one of the following:
- Bridge measurement
- Temperature coefficient of offset (Tco)
- Temperature coefficient of gain (Tcg)
The EEPROM bits 99:98 determine what SOT applies to.
TSETL
RAW_PTAT or ExtTemp reading (upper 7-bits) at low temperature at which calibration was performed
(typically room temperature)
Tcg
Temperature correction coefficient of bridge gain term. This term has an 8-bit magnitude and a sign bit
(Tc_cfg[2].
Tco
Temperature correction coefficient of bridge offset term. This term has an 8-bit magnitude, a sign bit
(Tc_cfg[0]), and a scaling bit (Tc_cfg[1]), which can multiply its magnitude by 8.
3.6.2.
Interpretation of Binary Numbers for Correction Coefficients
BR_Raw should be interpreted as an unsigned number in the set [0, 16383] with a resolution of 1.
T_Raw should be interpreted as an unsigned number in the set [0, 16383], with a resolution of 4.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
38 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
3.6.2.1. Gain_B Interpretation
Gain_B should be interpreted as a number in the set [0, 64]. The MSB (bit 14) is a scaling bit that will multiply the
effect of the Gain_B[13:0] term by 8. The remaining bits Gain_B[13:0] represent a number in the range of [0,8)
with Gain_B[13] having a weighting of 4, and each subsequent bit has a weighting of ½ the previous bit.
Table 3.7
Gain_B [13:0] Weightings
Bit Position
Weighting
13
2 =4
12
2 =2
11
2 =1
10
2
…
…
3
2
-8
2
2
-9
1
2
-10
0
2
-11
2
1
0
-1
Examples:
The binary number: 010010100110001B = 4.6489; Gain_B[14] is 0BIN, so the number represented by
Gain_B[13:0] is not multiplied by 8.
The binary number: 101100010010110B = 24.586; Gain_B[14] is 1BIN, so the number represented by
Gain_B[13:0] is multiplied by 8.
3.6.2.2. Offset_B Interpretation
Offset_B is a 14-bit unsigned binary number. The MSB has a weighting of 8192. The following bits then have a
weighting of: 4096, 2048, 1024 …
Table 3.8
Offset_B Weightings
Bit Position
Weighting
13
8192
12
4096
11
2048
.
.
.
1
1
2 =2
0
2 =1
0
For example, the binary number 1111 1111 1100 = 4092.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
39 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
3.6.2.3. Gain_T Interpretation
Gain_T should be interpreted as a number in the set [0,2]. Gain_T[7] has a weighting of 1, and each subsequent
bit has a weighting of ½ the previous bit.
Table 3.9
Gain_T Weightings
Bit Position
Weighting
7
2 =1
6
2 = 0.5
5
2 = 0.25
4
2
-3
3
2
-4
2
2
-5
1
2
-6
0
2
-7
0
-1
-2
3.6.2.4. Offset_T Interpretation
Offset_T is an 8-bit signed binary number in two’s complement form. The MSB has a weighting of -128.
The following bits then have a weighting of 64, 32, 16 …
Table 3.10 Offset_T Weightings
Bit Position
Weighting
7
-128
6
2 = 64
5
2 = 32
4
2 = 16
3
2 =8
2
2 =4
1
2 =2
0
2 =1
6
5
4
3
2
1
0
For example, the binary number 00101001B = 41.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
40 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
3.6.2.5. Tco Interpretation
Tco is specified as having an 8-bit magnitude with an additional sign bit and a scalar bit (Tc_cfg). When the scalar
bit is set, the signed Tco is multiplied by 8.
 Tco Resolution:
 Tco Range:
o
0.175 μV/V/ C
o
± 44.6 μV/V/ C
(input referred)
(input referred)
If the scaling bit is used, then the above resolution and range are scaled by 8 to give the following results:
 Tco Scaled Resolution:
 Tco Scaled Range:
o
1.40 μV/V/ C (input referred)
o
± 357 μV/V/ C (input referred)
3.6.2.6. Tcg Interpretation
Tcg is specified as an 8-bit magnitude with an additional sign bit (Tc_cfg).
 Tcg Resolution:
 Tcg Range:
o
17.0 ppm/ C
o
±4335 ppm/ C
3.6.2.7. SOT Interpretation
nd
SOT is a 2 order term that can apply to one and only one of the following: bridge non-linearity correction,
Tco non-linearity correction, or Tcg non-linearity correction.
As it applies to bridge non-linearity correction:
 Resolution: 0.25% @ full scale
 Range:
+25% @ full scale to -25% @ full scale
(Saturation in internal arithmetic will occur at greater negative nonlinearities.)
As it applies to Tcg:
 Resolution: 0.3 ppm/( C)
o
2
 Range:
+/- 38ppm/( C)
o
2
As it applies to Tco:
2 settings are possible. It is possible to scale the effect of SOT by 8. If Tc_cfg[1] is set, then both Tco and
SOT’s contribution to Tco are multiplied by 8.
 Resolution at unity scaling: 1.51nV/V/( C) (input referred)
o
2
 Range: +/- 0.192V/V/( C) (input referred)
o
2
 Resolution at 8x scaling: 12.1nV/V/( C) (input referred)
o
2
 Range: +/- 1.54V/V/( C) (input referred)
o
Data Sheet
June 3, 2014
2
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
41 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
3.7.
Reading EEPROM Contents
The contents of the entire EEPROM memory can be read out using the Read EEPROM command (00 HEX). This
command causes the ZSC31015 to output consecutive bytes on the ZACwire™. After each transmission, the
EEPROM contents are shifted by 8 bits. The bit order of these bytes is given in Table 3.11.
Table 3.11 EEPROM Read Order
Bit 7
Bit 6
Bit 5
Bit 4
Byte 1
Bit 3
Bit 2
Bit 1
Bit 0
Offset_B[7:0]
Byte 2
Gain_T[1:0]
Byte 3
Offset_T[1:0]
Gain_T[7:2]
Byte 4
TSETL[1:0]
Offset_T[7:2]
Offset_B[13:8]
Byte 5
Tcg[2:0]
TSETL[6:2]
Byte 6
Tco[2:0]
Tcg[7:3]
Byte 7
Tc_cfg[2:0]
Tco[7:3]
Byte 8
SOT[7:0]
Byte 9
Lock[0]
Diag_cfg[2:0]
Byte 10
SOT_cfg[3:0]
Up_Clip_Lim[5:0]
Byte 11
Lock[2 :1]
Low_Clip_Lim[6:0]
Byte 12
Cust_ID0[7:0]
Byte 13
Cust_ID1[7:0]
Byte 14
Cust_ID2[7:0]
Byte 15
Signature[7:0]
Byte 16
A2D_Offset[0]
Byte 17
JFET_cfg[0]
Byte 18
1V_Trim[3:0] **
Update_Rate[1:0]
Up_Clip_Lim[6]
Osc_Trim[2:0] **
Output Select[1:0]
A2D_Offset[3:1]
Gain_B[6:0]
JFET_cfg[1]
Byte 19
Gain_B[14:7]
Byte 20
A5HEX
* SOT_cfg/Pamp_Gain
** 1V_Trim/JFET_Trim
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
42 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
4
Application Circuit Examples
The minimum output analog load resistor is RL= 5k. This optional load resistor can be configured as a pull-up or
pull-down. If it is configured as a pull-down, it cannot be part of the module to be calibrated because this would
TM
prevent proper operation of the ZACwire . If a pull-down load is desired, it must be added to system after module
calibration.
There is no output load capacitance needed.
EEPROM contents: OUTPUT_select, Config_JFET_Regulation, 1V_Trim/JFET-Trim.
4.1.
Three-Wire Rail-to-Rail Ratiometric Output
This example shows an application circuit for rail-to-rail ratiometric voltage output configuration with temperature
compensation via an external diode. The same circuitry is applicable for a 0 to 1V absolute analog output.
Figure 4.1 Rail-to-Rail Ratiometric Voltage Output – Temperature Compensation via External Diode
Vsupply
+2.7 to +5.5 V
1 Bsink
VSS 8
2 VBP
SigTM 7
3 ExtTemp
4 VBN
Optional Bsink
OUT
VDD 6
Vgate 5
ZSC31015
0.1 F
Ground
The optional bridge sink allows a power savings of bridge current. The output voltage can be either

Rail-to-rail ratiometric analog output VDD(=Vsupply).

0 to 1V absolute analog output. The absolute voltage output reference is trimmable 1V (+/-3mV) in the
1V Output Mode via a 4-bit EEPROM field. See section 2.4.3).
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
43 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
4.2.
Absolute Analog Voltage Output
The figure below shows an application circuit for an absolute voltage output configuration with temperature compensation via internal temperature PTAT and external JFET regulation for all industry standard applications.
Figure 4.2 Absolute Analog Voltage Output – Temperature Compensation
via Internal Temperature PTAT with External JFET Regulation
BSS169
S
1 Bsink
VSS 8
2 VBP
SigTM 7
3 ExtTemp
4 VBN
Optional Bsink
D
Vsupply
+5.5 to +30 V
OUT
VDD 6
Vgate 5
ZSC31015
0.1 F
Ground
The output signal range can be one of the following options:
 0 to 1 V analog output. The absolute voltage output reference is trimmable: 1 V (+/-3 mV) in the 1 V Output
Mode via a 4-bit EEPROM field (see section 2.4.3).
 Rail-to-rail analog output. The on-chip reference for the JFET regulator block is trimmable: 5 V (±15 mV) in
the Ratiometric Output Mode via a 4-bit EEPROM field. (See section 2.4.3).
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
44 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
4.3.
Three-Wire Ratiometric Output with Over-Voltage Protection
The figure below shows an application circuit for a ratiometric output configuration with temperature compensation
via an internal diode. In this application, the JFET is used for voltage protection. JFET_cfg (16:15) in the
EEPROM are configured to 5.5V. There is an additional maximum error of 8mV caused by the non-zero rds(on) of
the limiter JFET.
Figure 4.3 Ratiometric Output, Temperature Compensation via Internal Diode
J107 Vishay
S
1 Bsink
VSS 8
2 VBP
SigTM 7
3 ExtTemp
4 VBN
Optional Bsink
D
Vsupply
+5.0 to +5.5 V
OUT
VDD 6
Vgate 5
ZSC31015
0.1 F
Ground
4.4.
Digital Output
For all three circuits, the output signal can also be digital. Depending on the output select bits, the bridge signal or
the bridge signal and temperature signal are sent. For the digital output, no load resistor or load capacity is
necessary. No pull down resistor is allowed. If a line resistor or pull-up resistor is used, the requirement for the
rise time must be met (< 5 s). The ZSC31015 output includes an internal pull up resistor of about 30 k. The
digital output can easily be read by firmware from a microcontroller, and ZMDI can provide the customer with
software for developing the interface.
4.5.
Output Resistor/Capacitor Limits
The limits for external components depend on the programmed output mode:
 Pure Analog Output Mode (calibration is done before): The only limit is the minimum load resistance of 5 k.
 Pure Digital Output Mode with end-of-line calibration: The RC time constant of the ZACwire™ line must have
a rise time < 5 µs.
 Analog output with digital communication during calibration: The RC time constant of the ZACwire™ line must
have a rise time < 5 µs.
Warning: Any series line resistance forms a voltage divider in conjunction with the pull-up load device. If a series
line resistance is needed, choose a low value relative to the pull-up load device.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
45 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
5
EEPROM Restoration
If needed, the default settings for the ZSC31015 (see Table 3.5) can be reprogrammed as described in section 3.
The following sections describe EEPROM content validation and handling during and/or after system assembly.
Important: During the sawing and dicing process, there is a possibility of the EEPROM contents flipping, and
prevention cannot be guaranteed. This is primarily a concern for the factory trim settings, which are customized to
each part.
The EEPROM default values programmed during the different test levels have been selected so that customer
has the option to refresh/reprogram trim bits that might have flipped during sawing or dicing.
Important: The EEPROM lock is stored in the bit range 105:103. A value of 6 HEX or 3HEX will lock the EEPROM
forever by disabling the charge pump needed for EEPROM writing. The complete contents can also be validated
using the EEPROM signature stored in bits [151:144], (see “Signature” in Table 3.5).
5.1.
Default EEPROM Contents
During the wafer level test (wafer/dice delivery) and during final test for SOP8 packaged parts, the EEPROM is
programmed with the default values listed in the Table 3.5. During the wafer level test, the Osc_trim bits [2:0] and
1V_Trim/JFET_Trim trim bits [6:3] are set to die-specific values.
5.1.1.
Osc_Trim
The oscillator frequency is trimmed to a value of 512kHz±20% using the Osc_Trim bit setting. The 3-bit setting is
copied twice to Cust_ID1[134:132] and [130:128] and then a third time to Cust_ID2[138:136] to ensure the factory
settings are retained so that the customer can reprogram these values in the Osc_Trim bit if needed. Based on
the most probable trimming, the default values for the Osc_Trim bits are always set to 0 HEX during factory testing
to guarantee communication even if bits have flipped.
5.1.2.
1V_Trim/JFET_Trim
The 5V reference for the JFET regulation is factory trimmed during the final test to 5V±15mV using the 1V_Trim/
JFET_Trim bit setting. The 4-bit setting stored in EEPROM bits [6:3] is copied twice to the Cust_ID0 bits [127:124]
and [123:120] to ensure the factory settings are retained so that the customer can reprogram these values in the
1V_Trim/JFET_Trim bits if needed.
5.2.
EEPROM Restoration Procedure
After module assembly, the EEPROM content should be refreshed. If JFET regulation is not used for the user’s
application and optimized response time is not an important criterion, write the default values shown in Table 3.5
to the EEPROM bit range [143:7] and retain the existing values in the bit range [6:0]. If JFET regulation or
optimized response time is required, the bit restoration procedure shown in the flow chart in Figure 5.1 must be
used to keep the factory settings programmed during the testing. If customer oscillator trimming is required, see
ZSC31015_Tech_Notes_JFET_and_Osc_Trimming_revX.X .pdf for instructions.)
Note: The EEPROM signature is re-calculated and updated after every EEPROM writing.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
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ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
Figure 5.1 EEPROM Validation and Restoration Procedure
Start CM
Restore Factory Trimming?
N
Y
Read EEPROM
Check Osc_Trim bits
[130:128]=[138:136]
Check Osc_Trim bits
[134:132]=[130:128]
N
N
Y
Y
Write
[134:132] to [2:0]
Check JFET_Trim bits
[6:3]=[127:124]
Keep bits [6:3]
N
Y
Write
[130:128] to [2:0]
Write
[134:132] to [2:0]
Check JFET_Trim bits
[123:120]=[127:124]
Check JFET_Trim bits
[6:3]=[123:120]
N
Y
Check Osc_Trim bits
[134:132]=[138:136]
N
Y
Write
[123:120] to[6:3]
Perform New
Osc_Trim
N
Y
Keep bits [6:3]
Perform New
JFET_Trim
Write EEPROM
default values
[143:7]
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
47 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
6
Pin Configuration and Package
The standard package of the ZSC31015 is an SOP-8 (3.81 mm / 150 mil body) with a lead-pitch 1.27 mm / 50 mil.
Table 6.1
Storage and Soldering Conditions for SOP-8 Package
Parameter
Symbol
Conditions
Maximum Storage Temperature
Tmax_storage
Less than 10hrs, before mounting
Minimum Storage Temperature:
Tmin_storage
Store in original packing only
Tdrybake
Less than100 hrs total, before
mounting
125
C
Less than 30s
(IPC/JEDEC-STD-020 Standard)
260
C
Maximum Dry-Bake Temperature
Soldering Peak Temperature
Tpeak
Min
Typical
Max
Units
150
C
C
-50
Figure 6.1 ZSC31015 Pin-Out Diagram
Table 6.2
Bsink
1
8
VSS
VBP
2
7
SigTM
ExtTemp
3
6
VDD
VBN
4
5
Vgate
ZSC31015 Pin Configuration
Pin No.
Name
Description
1
Bsink
Optional ground connection for bridge ground; used for power savings
2
VBP
Positive bridge connection
3
ExtTemp
External diode connection
4
VBN
Negative bridge connection
5
Vgate
Gate control for external JFET regulation/over-voltage protection
6
VDD
Supply voltage (2.7 to 5.5 V)
7
Sig™
ZACwire™ interface (analog out, digital out, calibration interface)
8
VSS
Ground supply
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
48 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
7
ESD/Latch-Up-Protection
All pins have an ESD protection of >4000V and a latch-up protection of 100 mA or of +8V/ –4V (to VSS/VSSA).
ESD protection referenced to the Human Body Model is tested with devices in SOP-8 packages during product
qualification. The ESD test follows the Human Body Model with 1.5kΩ/100pF based on MIL 883, Method 3015.7.
8
Test
The test program is based on this datasheet. The final parameters that are tested during series production are
listed in the tables of section 1.
The digital part of the IC includes a scan path, which can be activated and controlled during wafer test. Further
test support for testing of the analog parts on wafer level is included in the DSP.
9
Quality and Reliability
A reliability investigation according to the in-house non-automotive standard has been performed.
10
Customization
For high-volume applications, which require an upgraded or downgraded functionality compared to the
ZSC31015, ZMDI can customize the circuit design by adding or removing certain functional blocks.
For this customization, ZMDI has a considerable library of sensor-dedicated circuitry blocks, which enable ZMDI
to provide a custom solution quickly. Please contact ZMDI for further information.
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
49 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
11
Part Ordering Codes
Please contact ZMDI Sales for additional information.
Sales Code
Description
Package
ZSC31015EEB
ZSC31015 Die — Temperature range: -50°C to +150°C
Unsawn on Wafer
ZSC31015EEC
ZSC31015 Die— Temperature range: -50°C to +150°C
Sawn on Wafer Frame
ZSC31015EEG1-R
ZSC31015 SOP8 (150 mil) — Temperature range: -50°C to +150°C
Reel
ZSC31015EEG1-T
ZSC31015 SOP8 (150 mil) — Temperature range: -50°C to +150°C
Tube
ZSC31015EAB
ZSC31015 Die — Temperature range: -40°C to +125°C
Unsawn on Wafer
ZSC31015EAC
ZSC31015 Die— Temperature range: -40°C to +125°C
Sawn on Wafer Frame
ZSC31015EAG1-R
ZSC31015 SOP8 (150 mil) — Temperature range: -40°C to +125°C
Reel
ZSC31015EAG1-T
ZSC31015 SOP8 (150 mil) — Temperature range: -40°C to +125°C
Tube
ZSC31015EIB
ZSC31015 Die— Temperature range: -25°C to +85°C
Unsawn on Wafer
ZSC31015EIC
ZSC31015 Die — Temperature range: -25°C to +85°C
Sawn on Wafer Frame
ZSC31015EIG1-R
ZSC31015 SOP8 (150 mil) — Temperature range: -25°C to +85°C
Reel
ZSC31015EIG1-T
ZSC31015 SOP8 (150 mil) — Temperature range: -25°C to +85°C
Tube
ZSC31015KIT
ZSC31015 ZACwire™ SSC Evaluation Kit: Communication Board, SSC Board, Sensor Replacement
Board, USB Cable, 5 IC Samples (SOP8)
Kit
(ZACwire™ SSC Evaluation Software can be downloaded from www.zmdi.com/zsc31015)
Contact ZMDI Sales for support and sales of ZMDI’s ZSC31015 Mass Calibration System.
12
Related Documents
Note: Rev_X_xy refers to the current revision of the document.
Document
File Name
ZACwire™ SSC Evaluation Kit Description
ZACwire_SSC_Evaluation_Kit_Rev_X_xy.pdf
ZSC31015 Die Dimensions and Pad Coordinates**
ZSC31015_Tech_Notes_Die_Pads_Rev_X_xy.pdf
SSC Evaluation Kits Feature Sheet *
(includes ordering codes)
SSC_Evaluation_Kits_FeatureSheet_Rev_X_xy.pdf
ZSC31010/31015/31050 Application Note – External
Protection Circuitry
ZSC31010/31015/31050_AN_Ext_Prot_Circuit_Rev_X_xy.pdf
ZMDI Wafer Dicing Guidelines
ZMDI_Wafer_Dicing_Guidelines_Rev_X_xy.pdf
Visit the ZSC31015 product page (www.zmdi.com/zsc31015) on ZMDI’s website www.zmdi.com or contact your nearest sales
office for the latest version of these documents.
* Documents marked with an asterisk (*) can be found on the Evaluation Tools page (www.zmdi.com/ssc-tools).
** Documents marked with two asterisks (**) are available on request (see page 53).
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
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ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
13
Definitions of Acronyms
Term
Description
ADC
Analog-to-Digital Converter
AFE
Analog Front-End
BUF
Buffer
CM
Command Mode
CMC
Calibration Microcontroller
DAC
Digital-to-Digital Converter
DNL
Differential Nonlinearity
DSP
Digital Signal Processor
DUT
Device Under Test
ESD
Electrostatic Discharge
FSO
Full-Scale Output
INL
Integrated Nonlinearity
LSB
Least Significant Bit
MUX
Multiplexer
NOM
Normal Operation Mode
OWI
One-Wire Interface
POC
Power-On Clear
POR
Power-On Reset Level
PSRR
Power Supply Rejection Ratio
PTAT
Proportional To Absolute Temperature
RM
Raw Mode
SOT
Second Order Term
Data Sheet
June 3, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
51 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
14
Document Revision History
Revision Date
Description
1.40
February 24, 2009
Revision to Byte 16 in Table 3.11.
Revision to add an explanation for default setting in Table 3.5.
Revision to “Lower Output Voltage Limit” specification in section 1.3.5.
Revisions in sections 2.4.3 and 2.5.1 to text regarding regulator set point and optimal
reference trim, including text about methods for preserving factory settings.
Revision to caption for Figure 3.2 to clarify that timing is typical.
Revision to text below Table 3.2 regarding minimum and maximum baud rate.
Added note below Table 3.3 clarifying that timing is typical.
Revisions to the default settings column and explanations for the Cust_ID0 and Cust_ID1
EEPROM words in Table 3.5.
Addition of section 5 to explain methods for restoration of EEPROM settings.
1.50
May 14, 2009
Revised conditions for “Overall Ratiometricity Error” and “Overall Accuracy – Analog”
specifications in section 1.3.9.
1.60
June 10, 2009
Added “Document Revision History” table.
1.70
March 29, 2010
Corrected start-up window time 1.5 to 3ms. This change applies only to rev C1 Silicon
(marked as ZSC31015Cxx.) and higher. Stop bit definition is replaced by stop time
definition. Relocated specs from Table 1.9 and deleted Table 1.9.
1.73
May 11, 2010
Added footnote to pages 2, 3, and 14 clarifying that the ZSC31015 is not AEC-Q100qualified.
1.74
July 19, 2010
Added special measurement information to Table 3.2; revised precondition for equation (1).
1.80
July 27, 2010
Revised product name from ZMD31015 to ZSC31015.
1.90
March 24, 2011
Added EEPROM specifications to section 1.3 “Electrical Parameters.” Added table 6.1
“Storage and Soldering Conditions” to section 6 “Pin Configuration and Package.” Updated
trim tolerances in sections 4.1and 4.2. Updated ZMDI contact information.
1.91
October 8, 2011
Revisions in section 1.3.4. Addition of part ordering numbers for all available temperature
ranges to section 11. Update for sales contact information to add ZMDI’s Korea office.
Revision of product title.
1.92
January 12, 2012
Removed requirement of fastest update rate for analog output mode (applied to previous IC
revision). Updated contact information for the USA.
2.00
October 28, 2012
Updates to contact information and part ordering numbers.
2.10
October 9, 2013
Update to section 1.2 to add new minimum specification for output load capacitance.
Update to section 1.3.9 for tSTA maximum specification.
Updates to contact information and imagery for cover and headers.
Updates to part order options.
Updates to related documents.
2.11
December 11, 2013 Update for part ordering tables: kit no longer includes DVD of software. Software is now
downloaded from www.zmdi.com/zsc31015 to ensure user has the latest version of
software.
2.12
June 3, 2014
Data Sheet
June 3, 2014
Update to section 1.2 regarding minimum bridge resistance values. Update to section 2.6.3
regarding minimum bridge resistance values.
Update for “Related Documents” section and ZMDI contact information.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
52 of 53
ZSC31015
RBicdLite™ Analog Output Sensor Signal Conditioner w/ Diagnostic Features
Sales and Further Information
www.zmdi.com
[email protected]
Zentrum Mikroelektronik
Dresden AG
Global Headquarters
Grenzstrasse 28
01109 Dresden, Germany
ZMD America, Inc.
1525 McCarthy Blvd., #212
Milpitas, CA 95035-7453
USA
Central Office:
Phone +49.351.8822.306
Fax
+49.351.8822.337
USA Phone 1.855.275.9634
Phone +1.408.883.6310
Fax
+1.408.883.6358
European Technical Support
Phone +49.351.8822.7.772
Fax
+49.351.8822.87.772
DISCLAIMER: This information applies to a product under development. Its characteristics and specifications are subject to change without notice.
Zentrum Mikroelektronik Dresden AG (ZMD AG) assumes no obligation regarding future manufacture unless otherwise agreed to in writing. The
information furnished hereby is believed to be true and accurate. However, under no circumstances shall ZMD AG be liable to any customer,
licensee, or any other third party for any special, indirect, incidental, or consequential damages of any kind or nature whatsoever arising out of or
in any way related to the furnishing, performance, or use of this technical data. ZMD AG hereby expressly disclaims any liability of ZMD AG to any
customer, licensee or any other third party, and any such customer, licensee and any other third party hereby waives any liability of ZMD AG for
any damages in connection with or arising out of the furnishing, performance or use of this technical data, whether based on contract, warranty,
tort (including negligence), strict liability, or otherwise.
European Sales (Stuttgart)
Phone +49.711.674517.55
Fax
+49.711.674517.87955
Data Sheet
June 3, 2014
Zentrum Mikroelektronik
Dresden AG, Japan Office
2nd Floor, Shinbashi Tokyu Bldg.
4-21-3, Shinbashi, Minato-ku
Tokyo, 105-0004
Japan
ZMD FAR EAST, Ltd.
3F, No. 51, Sec. 2,
Keelung Road
11052 Taipei
Taiwan
Phone +81.3.6895.7410
Fax
+81.3.6895.7301
Phone +886.2.2377.8189
Fax
+886.2.2377.8199
Zentrum Mikroelektronik
Dresden AG, Korea Office
U-space 1 Building
11th Floor, Unit JA-1102
670 Sampyeong-dong
Bundang-gu, Seongnam-si
Gyeonggi-do, 463-400
Korea
Phone +82.31.950.7679
Fax
+82.504.841.3026
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 2.12
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
53 of 53