Analog Signal Processor Performs Sensor Calibration And Compensation

MAX1457 monolithic analog signal processor is optimized for the calibration and compensation of piezo-resistive sensors and includes a programmable current source for sensor excitation, 3-bit programmable-gain amplifier, 12-bit ADC, uncommitted op amp, and five 16-bit DACs. Compensating the sensor for offset, full span output, offset TC, FSO TC, and full span output non-linearity, the MAX1457 achieves a total error less than 0.1% of the sensor's repeatability error. DACs enable the MAX1457 to nullify first-order temperature errors by adjusting the input signal's span and offset. If necessary, higher order residual errors can be compensated using a linear interpolation of first-order coefficients stored in an external EEPROM lookup table.