MAX1458 Datasheet, PDF (1/20 Pages) Maxim Integrated Products – 1%-Accurate, Digitally Trimmed Sensor Signal Conditioner

19-1373; Rev 0; 5/98
1%-Accurate, Digitally Trimmed
Sensor Signal Conditioner
General Description
The MAX1458 highly integrated analog-sensor signal
processor is optimized for piezoresistive sensor calibra-
tion and compensation without any external compo-
nents. It includes a programmable current source for
sensor excitation, a 3-bit programmable-gain amplifier
(PGA), a 128-bit internal EEPROM, and four 12-bit
DACs. Achieving a total error factor within 1% of the
sensor’s repeatability errors, the MAX1458 compen-
sates offset, offset temperature coefficient, full-span
output (FSO), FSO temperature coefficient (FSOTC),
and FSO nonlinearity of silicon piezoresistive sensors.
The MAX1458 calibrates and compensates first-order
temperature errors by adjusting the offset and span of
the input signal via digital-to-analog converters (DACs),
thereby eliminating quantization noise. Built-in testabili-
ty features on the MAX1458 result in the integration of
three traditional sensor-manufacturing operations into
one automated process:
• Pretest: Data acquisition of sensor performance
under the control of a host test computer.
• Calibration and compensation: Computation and
storage (in an internal EEPROM) of calibration and
compensation coefficients computed by the test
computer and downloaded to the MAX1458.
• Final test operation: Verification of transducer cali-
bration and compensation without removal from the
pretest socket.
Although optimized for use with piezoresistive sensors,
the MAX1458 may also be used with other resistive
sensors (i.e., accelerometers and strain gauges) with
some additional external components.
______________________Customization
Maxim can customize the MAX1458 for unique require-
ments. With a dedicated cell library consisting of more
than 90 sensor-specific functional blocks, Maxim can
quickly provide customized MAX1458 solutions. Please
contact Maxim for further information.
________________________Applications
Piezoresistive Pressure and Acceleration
Transducers and Transmitters
MAP (Manifold Absolute Pressure) Sensors
Automotive Systems
Hydraulic Systems
Industrial Pressure Sensors
Features
o Medium Accuracy (±1%), Single-Chip Sensor
Signal Conditioning
o Sensor Errors Trimmed Using Correction
Coefficients Stored in Internal EEPROM—
Eliminates the Need for Laser Trimming and
Potentiometers
o Compensates Offset, Offset-TC, FSO, FSOTC,
FSO Linearity
o Programmable Current Source (0.1mA to 2.0mA)
for Sensor Excitation
o Fast Signal-Path Settling Time (<1ms)
o Accepts Sensor Outputs from 10mV/V to 40mV/V
o Fully Analog Signal Path
Ordering Information
PART
TEMP. RANGE PIN-PACKAGE
MAX1458CAE
0°C to +70°C
16 SSOP
MAX1458C/D
0°C to +70°C
Dice*
MAX1458AAE
-40°C to +125°C 16 SSOP
*Dice are tested at T_A = +25°C, DC parameters only.
Functional Diagram appears at end of data sheet.
Pin Configuration
TOP VIEW
SCLK 1
CS 2
I.C. 3
TEMP 4
FSOTC 5
DIO 6
WE 7
V_SS 8
MAX1458
SSOP
16 LIMIT
15 V_DD
14 INP
13 BDRIVE
12 INM
11 I.C.
10 OUT
9 ISRC
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