MAX1458

The MAX1458 highly integrated analog-sensor signal processor is optimized for piezoresistive sensor calibration and compensation without any external components. 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 compensates 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 testability 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 calibration 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.