MAX1450 Datasheet, PDF (1/12 Pages) Maxim Integrated Products – Low-Cost, 1%-Accurate Signal Conditioner for Piezoresistive Sensors

19-1365; Rev 0; 5/98
Low-Cost, 1%-Accurate Signal Conditioner
for Piezoresistive Sensors
General Description
The MAX1450 sensor signal conditioner is optimized for
piezoresistive sensor calibration and temperature com-
pensation. It includes an adjustable current source for
sensor excitation and a 3-bit programmable-gain amplifi-
er (PGA). Achieving a total typical error factor within
1% of the sensor’s inherent repeatability errors, the
MAX1450 compensates offset, full-span output (FSO), off-
set tempco, FSO tempco, and FSO nonlinearity of silicon
piezoresistive sensors via external trimmable resistors,
potentiometers, or digital-to-analog converters (DACs).
The MAX1450 is capable of compensating sensors that
display close error distributions with a single tempera-
ture point, making it ideal for low-cost, medium-accuracy
applications. Although optimized for use with popular
piezoresistive sensors, it may also be used with other
resistive sensor types such as strain gauges.
Customization
Maxim can customize the MAX1450 for unique require-
ments including improved power specifications. With a
dedicated cell library consisting of more than 90 sen-
sor-specific functional blocks, Maxim can quickly pro-
vide customized MAX1450 solutions. Contact the
factory for additional information.
Applications
Piezoresistive Pressure and Acceleration
Transducers and Transmitters
Manifold Absolute Pressure (MAP) Sensors
Automotive Systems
Hydraulic Systems
Industrial Pressure Sensors
Pin Configuration
TOP VIEW
INP 1
I.C. 2
I.C. 3
SOTC 4
SOFF 5
A1 6
A0 7
OFFTC 8
OFFSET 9
BBUF 10
MAX1450
20 INM
19 V_SS
18 BDRIVE
17 ISRC
16 I.C.
15 V_DD
14 OUT
13 A2
12 I.C.
11 FSOTRIM
Features
o 1% Sensor Signal Conditioning
o Corrects Sensor Errors Using Coefficients Stored
in External Trimmable Resistors, Potentiometers,
or DACs
o Compensates Offset, Offset TC, FSO, FSO TC,
and FSO Linearity
o Rail-to-Rail^® Analog Output
o Programmable Current Source for Sensor
Excitation
o Fast Signal-Path Settling Time (< 1ms)
o Accepts Sensor Outputs from 10mV/V to 30mV/V
o Fully Analog Signal Path
Ordering Information
PART
TEMP. RANGE PIN-PACKAGE
MAX1450CAP
0°C to +70°C
20 SSOP
MAX1450C/D
0°C to +70°C
Dice*
MAX1450EAP
-40°C to +85°C
20 SSOP
* Dice are tested at T_A = +25°C, DC parameters only.
Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd.
Functional Diagram
FSOTRIM V_DD
CURRENT
SOURCE
ISRC
V_DD
BDRIVE
INP
INM
+
PGA
-
A=1
MAX1450
A2
A1
A0
OUT
SOTC
SOFF
OFFTC
OFFSET
BBUF
SSOP
V_SS
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