Sensor & Signal Conditioner Product Selector

Product Portfolio Brief
SEMTECH
WIRELESS
&
SENSING
PRODUCTS
Data Acquisition Solutions
Low power, high precision
World’s most flexible acquisition solutions
Semtech’s over-sampled ADC technology allows users to achieve high
performance functionality using low cost sensor and minimal power supply.
Semtech offers a range of low-power mixed-signal
ICs for Data Acquisition. The range includes
The ZoomingADC™ high resolution ADC with
serial interface and with MCU, as well as digital
temperature sensors.
Applications
• Portable, battery operated instruments
• RF powered instruments
• Solar powered instruments
• 4-20 mA loop powered sensors
Semtech Data Acquisition Solutions are characterized
by their miniaturization, flexibility and low-power
operation.
Key Features
• ZoomingADC:
- 16 bit ADC
- Embedded programmable gain 1/12 to 1000
- Embedded sensor offset compensation
- Low power, 200 uA for 16b at 1kHz
• Wireless sensors
• On chip CPU:
• Pressure sensors
- Wide voltage range, 2.4 – 5.5 V
• Magnetic sensors
- Low power, 300 uA/MIPS
• Acceleration and tilt sensors
• Humidity sensors
• Temperature monitoring
- Printers
- Servers
- Set Top Boxes
• Digital temperature sensor:
- Precision +/- 0.5°C typ
- Low power, 250 uA at 10 Hz
- Up to 4 temperature zones
- Resistive error cancellation
- Projectors
W W W .SE MTE C H .C OM
Data Acquisition Solutions
SX8733, SX8743 and SX8744
SX8733
P1
1
AL1 AL2
6
P2
5
VDD
4
SMBCLK
ALARM
+
+
-
D1+
2 D1D2+
D2-
SMBDAT
VDD
1
P3
2
SX8743
MUX
VSS
3
+ ADC
SMBUS
8
SMBCLK
VDD
1
7
SMBDAT
P1
2
SX8744
AL1 AL2
P1
4
+++-
+ ADC
SMBUS
SMBCLK
7
SMBDAT
6
P4
5
VSS
AL1 AL2
6
P4
P2
3
5
VSS
NC
4
ALARM
D1+
D1-
+-
D2+
D2-
+
-
General Description
Applications
The SX8733, SX8743 and SX8744 are digital temperature
sensors with a 2-wire SMBus interface. It provides a
lowcost solution to monitor the temperature of remote
diodes as well as its own temperature with an on-chip PN
junction sensor.
• Printer
Depending on the device version, 2, 3 or 4 programmable
ports are included. They offer the possibility to trig under/over- temperature alarms which can be used as an
interrupt or to connect up to 3 external sensors in singleended mode or 2 external sensors in differential mode.
The parasitic resistances in series with the temperature
monitoring diode can be cancelled by an algorithmic, a
3-point or a Kelvin (4-wire) method.
MUX
3
D1+
D1D2+
D2D3+
D3-
MUX
P2
ALARM
8
+ ADC
SMBUS
• Server
• Set top box
• Projector
• Batteries charger monitoring
Key Product Features
• 1 internal and up to 3 external sensors
• Remote diode temp. accuracy of ±0.5°C on the
temp. range 25°C to 100°C
The SX8744 is pin-to-pin compatible with the LM86 part.
• 2 temp. output formats: 0°C to 127°C and
-40°C to 140°C with 0.125°C resolution
The SX8733 (2 programmable ports) is available in
MLPD- 6 package.
• Parasitic series resistance cancellation:
Algorithmic, 3- point and Kelvin (4-wire)
The SX8743 (4 programmable ports) and SX8744 (3
programmable ports) are available in MSOP-8 package.
• Under-/over- temp. alarms with programmable
thresholds programmable conversion rate for
optimal power consumption
Ordering Information
Part Number
Feature
Package
SX8733EWLTRT
2 Programmable ports
MLPD-6
SX8743EMSTRT
4 Programmable ports
MSOP-8
SX8744EMSTRT
3 Programmable ports
MSOP-8
• 250 uA active current @ 10Hz sampling rate
• SMBus v2.0 interface supports timeout
• Pb-Free, halogen free, RoHS/WEEE compliant
W W W. S E M T E C H .C O M
-2-
Data Acquisition Solutions
Low-Power Precision Temperature Monitoring
SX8733 / SX8743 / SX8744 include an on-chip PN junction to measure local temperature TJ.
The device has a 2-level current source and
an ADC to measure each diode’s forward
voltage to compute the temperature. The
input multiplexer allows 3 external and 1
internal sensors to be connected to the ADC.
Two alarms can provide to the system the
information that a sensor temperature has
reached the programmable threshold.
The chip is configured with a 2-wire
SMBus serial line.
A wide range of operating modes are proposed to measure from a single temperature zone up to 4 zones, and
generate up to two alarms triggered by different temperature levels. Sensor can be connected in differential mode
for best cancellation of noise or single ended to allow for more sensors. Algorithms are included to cancel the effect
of lines resistivity.
0
1
2
3
4
5
6
7
8
9
External Sensor
Mode
1
1
1
0
2
2
1
1
1
1
Differential
x
x
x
x
Single-ended
x
Algorithmic track
resistance cancellation
x
x
3-point track
resistance cancellation
x
x
x
x
10 11 12 13 14 15 16
1
2
2
x
x
x
x
2
2
3
17
3
18 19 20
3
x
x
x
x
x
x
x
x
x
x
x
Kelvin (4-wire) track
resistance cancellation
Alarm #
1
x
x
x
x
2
x
0
0
0
2
0
0
1
1
2
2
2
0
0
2
2
1
1
1
1
0
In a typical application, the SX8743 will monitor
its own temperature and one sensor. When any of
these is higher than a predefined threshold, it shall
send an alarm to trigger its host CPU. One alarm
could also be directly connected to a fan to cool
down the system without waking the host.
W W W. S E M T E C H .C O M
-3-
Data Acquisition Solutions
Solutions using the ZoomingADCTM
1. Industrial Pressure Sensor
Realizing an industrial pressure sensor with an
XE8805A is quite straightforward. A bridge sensor
element has its bias connected between one of
the DAC buffers of the XE8805A, and the sensing
pins are connected to one pair of input of the
ZoomingADC. A temperature sensor is connected
to a second input pair of the ZoomingADC, if
temperature correction is required.
The PGA (zoom of the ZoomingADC) converts the
millivolt output of the bridge to a bigger signal than
the ADC can convert with full resolution.
4-20 mA Sensing Block Diagram
5V
ADC
Resolution
Speed
MCU
PGA
M
U
X
VE88LC05
Global function (ZoomingADC + MCU for correction
computation) uses less than 1.5 milliampere, so
there is still ample current to bias the sensor in a
4-20 mA loop.
2. Barometer
The barometer is a pressure sensor and can use
the same architecture as above (industrial pressure sensor).
4-20 mA Sensing Application
ROM,
Flash
Then the signal can be provided to the output via the
UART for digital sensor interfaces, or via the second
DAC for analog output (like 4-20 mA loop).
The barometer is a very low bandwidth sensor, so
its mean current consumption can be significantly
reduced by using the XE8801A, with its very flexible
sleep modes. The XE8801A can maintain a precise
real time clock with less than 2 microampere. By
measuring the pressure every second, the mean
current consumption of a barometer based on the
XE8801A is lower than 3 microampere.
For a barometer with an LCD display, one can develop
with the XE8802, as it has a LCD driver. For small
displays, the lowest cost solution is to use resistors to
create a simple multiplexer around the digital port of
the XE8801A.
Signal-DAC
Gain
Offset
Clocks
UART
PIO
RAM
XE8801A Circuit Diagram
Bias-DAC
Bridge
Bias
The MCU is available for further correction of the
signal amplitude and offset. Its high efficiency
makes it possible to have rapid computation while
using very little current. The following polynomial
can be computed with a 16 bits resolution in 150
microsecond with a total current in the MCU of 600
microampere.
Out= (A0+A1•T) •Vin+B0+B1• T
W W W. S E M T E C H .C O M
-4-
Data Acquisition Solutions
Solutions using the ZoomingADCTM
3. Miniature Compass
A compass is another sensor that can benefit
from a ZoomingADC. The sensing element can
be a “Hall”, “AMR” or a “GMR” sensor, depending
on what principle is used for detection of the
magnetic field.
DAC
Flash
Memory
UART
DAC
RISC
CPU
PWM
MSGs1
Value
Unit
Sensor Sensitivity
3.2
mV/V/Oe
Sensor offset
10
mV/V
Full scale signal under earth
magnetic field (30 µT)
+/- 1
mV/V
Rem: Oe stands for Oersted. 1 Oe is 1 Gauss in vacuum, 1 Gauss is 100 µT (microTesla).
One of the main advantages of the ZoomingADC for
this type of application is that one has enough analog differential inputs and digital outputs to change
the direction of the sensor bias and get rid of its
large offset.
ZoomingADCTM Settings
Value
Unit
Sensor Signal (Offset + Signal)
10 +/- 1
mV/V
Signal out of Preamp. 1, gain 10
100 +/- 10
mV/V
Signal out of Preamp. 2, gain 10,
offset -1
0 +/- 100
mV/V
Signal out of Preamp. 3, gain 5
0 +/- 500
mV/V
ADC (Full scale is +/- Vref/2)
+/- 32767
LSB
Miniature solutions can be made, as no external
components are needed to read the Hall sensor with
an XE8801A or an XE8805A.
4. Air Quality Monitor
Air quality monitoring can be done with one or a
few chemical sensing elements (i.e. Microsens
MSGS3001 device). These sensing elements must
be precisely biased to have correct sensitivity and a
long life.
RS232
Xtal2
MSGs2
LCD
ADC
Temp
ZoomingADC
Parameter (Typical AMR Sensor)
MAX232
Vref
MTP Program
RESET
Power
Supply
The sensing elements function by rapidly heating a
small silicon bridge on which a sensitive resistor is
placed. Resistivity of this element changes with the
concentration of the chemicals to be detected.
By having good control of the applied voltage, one
can also significantly lower the global energy required
for reading the sensing elements. This ends with
ultra low-power solutions, even if the heating of the
sensing element requires several 10 milliwatts. The
mean power requirement can be as low as a few 10
microwatts.
5. Wireless Sensing
The low power and excellent computing capabilities of
the XE8000 series make them perfectly suited for RF
linked sensors.
The XE8000 can directly interface with a transceiver
(like the ultra low-power XE1200 series from Semtech) to
send the acquired data over a RF signal to a main
station. The low power-capabilities of the XE8000
allows it to run on batteries for years, even when
working with an RF link.
6. Other Sensors
Most current sensors generate a voltage or a current
that is proportional to the signal to be measured. All
these sensors can be read directly by the ZoomingADC
with the help of an additional resistor to produce a
signal-in current.
W W W. S E M T E C H .C O M
-5-
Data Acquisition Solutions
What is the ZoomingADCTM
ZoomingADC™ technology was developed as a result
of more than 10 years of knowledge of high-end mixed
signal circuits for industrial applications. It includes all
the functions necessary to read a piezo-resistive bridge.
Excellent INL over temperature
INL: Gain 1000 -40°C
PGA1=10; PGA2=10; PGA3=10;
set_osr=7; set_nelconv=3; Vbat=5V; Vref=5V; Vcommon=0V
+
+
+
+
+
+
-
-
-
-
-
-
-
Gain1
+
Offset 2 Gain2
+
-
+
-
Signal
ADC
INL [LSB]
ZoomingADC Architecture
Offset3 Gain3
It compensates for a low sensitivity sensor with a
high gain, and cancels the sensor’s offset through a
controlled addition of the reference to the signal path.
The ZoomingADC also includes the necessary output
peripherals, such as UART and parallel I/O. Some
products also include an LCD driver or buffered ADC.
INL: Gain 1000 85°C
PGA1=10; PGA2=10; PGA3=10;
set_osr=7; set_nelconv=3; Vbat=5V; Vref=5V; Vcommon=0V
INL [LSB]
In addition to the advanced ADC, the circuit also
has a complete microcontroller (MCU) for managing
the ZoomingADC, and for processing the data. This
controller can carry out a simple polynomial correcting
in a few microseconds.
Vin [mV]
Features
• 16 bits incremental programmable oversampled ADC
• Up to 16 bits in 1 ms, 12 bits in 250 µs, or 8 bits
in 75 µs
Vin [mV]
The ZoomingADC resolution can be
programmed versus the acquisition time:
Resolution vs Acquisition Time
• Pre amplification gain up to 1000 in steps of 10%
• Offset cancellation up to 15 FS in steps of 10%
Resolution [bits]
• Complete internal offset cancellation scheme
Time [µs]
W W W. S E M T E C H .C O M
-6-
Tools Selection Guide
Evaluation Tools
SX87xx Tools
• Evaluation board with USB connection and
experimentation wrap area
• Simple GUI with full visibility on all registers
USB
SX87xx Products
Product
Package
SX8723E083TDT
MLPD-12
SX8724E082TDT
MLPQ-16
SX8725E083TDT
MLPD-12
SX8723CWLTDT
MLPD-12
SX8724CWLTDT
MLPQ-16
SX8725CWLTDT
MLPD-12
SX8733EWL
MLPD-6
SX8743EMS
MSOP-8
SX8744EMS
MSOP-8
Evaluation Kit
XE8000EV121
based on SX8724E082TDT
SX8000EV126
SX/XE88xx Tools
RS-232
RIDE Base OR
• Editor
• Assembler
• C Computer
• Linker
• Simulator (4k)
• In-Socket - Debugger
RIDE Enterprise
• RIDE Base +
• Unlimited simulator
• Code Compressor
• Multi-processor
• Script Support
Programmers
BPmicro, Phyton
XE8000MP
Multi-purpose board
PICE-XE
Phyton, LC02 or 06 based, serves all
Target Application
XE8000EV1xx
Chip specific evaluation board
Short Tools Selection Guide
Most XE88xx customers develop using the free version of Raisonance RIDE (downloaded from Raisonance website),
XE8000MP and the corresponding XE8000EV1xx.
XE88xx Products
Product
Package
XE8801AMI027
LQFP44
XE8802MI035
LQFP100
XE8805AMI028
LQFP64
Provider:
ProStart II
Software
MP Board
RIDE
XE8000MP
Multi-purpose board
Rais. *
Emulator PICE
Evaluation
Board
Semtech
Main
POD
XE8000EV101
XE8000EV110
XE8000EV104
Adapter
AR1-XE-02-Q44
MR1-XE-01
PR1-XE-020
AR1-XE-02-Q100
AR1-XE-02-Q64
Phyton, www.phyton.com
Rais. *= Raisonance. www.raisonance.com
W W W. S E M T E C H .C O M
-7-
Product Line Card
ZoomingADC with serial interfaces
Part
Number
Supply
Voltage
Supply
Current
Inputs
Main Function
Other Features
Packages
SX8723
2.4V to 5.5V
200 µA
2 differential inputs
high resolution
acquisition path
ZoomingADC with
1 to 1000 gain
16 bit over-sampled ADC
Embedded voltage
reference, 2-wire i/f,
2 parallel I/Os
MLPD12
4x4 mm2
SX8724
2.4V to 5.5V
200 µA
3 differential inputs
high resolution
acquisition path
ZoomingADC with
1 to 1000 gain
16 bit over-sampled ADC
Embedded voltage
reference, 2-wire i/f,
4 parallel I/Os
MLPQ16
4x4 mm2
SX8725
2.4V to 5.5V
200 µA
1 differential input
high resolution
acquisition path
ZoomingADC with
1 to 1000 gain
16 bit over-sampled ADC
Embedded voltage
reference, 2-wire i/f,
2 parallel I/Os
MLPD12
4x4 mm2
SX8723C
2.4V to 5.5V
200 µA
2 differential inputs
high resolution
acquisition path
ZoomingADC with
1 to 1000 gain
16 bit over-sampled ADC
Embedded voltage
reference, I2C interface,
2 parallel I/Os
MLPD12
4x4 mm2
SX8724C
2.4V to 5.5V
200 µA
3 differential inputs
high resolution
acquisition path
ZoomingADC with
1 to 1000 gain
16 bit over-sampled ADC
Embedded voltage
reference, I2C interface,
4 parallel I/Os
MLPQ16
4x4 mm2
SX8725C
2.4V to 5.5V
200 µA
1 differential input
high resolution
acquisition path
ZoomingADC with
1 to 1000 gain
16 bit over-sampled ADC
Embedded voltage
reference, I2C interface,
2 parallel I/Os
MLPD12
4x4 mm2
Digital temperature sensing
SX8733
2.7 to
5.5 V
250 µA
Internal sensor, up to 2
external sensors
Precision temperature
acquisition
SMBus interface,
resistive cancellation
MLPD-6
3x3 mm2
SX8743
2.7 to
5.5 V
250 µA
Internal sensor, up to 3
external sensors
Precision temperature
acquisition
SMBus interface,
resistive cancellation
MSOP-8
3x3 mm2
SX8744
2.7 to
5.5 V
250 µA
Internal sensor, up to 2
external sensors
Precision temperature acquisition,
LM86 pin compatible
SMBus interface,
resistive cancellation
MSOP-8
3x3 mm2
ZoomingADC with high efficiency MCU and serial interfaces
XE8801A
SX8801R**
2.4V to 5.5V
XE8802
2.4V to 5.5V
XE8805A
2.4V to 5.5V
4 differential inputs
high resolution
acquisition path
ZoomingADC with 1 to 1000 gain
16 bit over-sampled ADC
MCU and RAM for local data
processing
UART, 24 parallel I/O
programmable clock
PWM DACs
LQFP44
200 µA
4 differential inputs
high resolution
acquisition path
ZoomingADC with 1 to 1000 gain
16 bit over-sampled ADC
MCU and RAM for local data
processing
UART, up to 60
parallel I/O, PWM DACs
programmable clock,
4 low-power comparators
120 segments LCD driver
with voltage reference
LQFP100
200 µA
4 differential inputs
high resolution
acquisition path
ZoomingADC with 1 to 1000 gain
16 bit over-sampled ADC
MCU and RAM for local data
processing
UART, 24 parallel I/O
programmable clock
2 DACs with buffers
LQFP64
200 µA
** SX8801R is a ROM (Ready only memory) version of the XE8801A
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