General Description

The MAX1459 highly integrated analog-sensor signal conditioner is optimized for piezoresistive sensor calibration and compensation with minimal 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 MAX1459 compensates offset, offset temperature coefficient (offset TC), full-span output (FSO), FSO temperature coefficient (FSOTC), and FSO nonlinearity of silicon piezoresistive sensors.

Features

♦ Highly Integrated Sensor Signal Conditioner for 2-Wire, 4–20mA Transmitters

♦ Sensor Errors Trimmed Using Correction

  Coefficients Stored in Internal EEPROM—Eliminates the Need for Laser Trimming and Potentiometers

♦ Compensates Offset, Offset TC, FSO, FSOTC, FSO Linearity

♦ Programmable Current Source (0.1mA to 2.0mA) for Sensor Excitation

♦ Fast Signal-Path Settling Time (≈1ms)

♦ Accepts Sensor Outputs from +1mV/V to +40mV/V

♦ Fully Analog Signal Path

♦ Internal or External Temperature Reference Compensation

♦ Automated Pilot Production (Calibration/Compensation) System Available

♦ Write Protection for EEPROM Data Security

Applications

  4–20mA Transmitters

  Piezoresistive Pressure and Acceleration

  Industrial Pressure Sensors

  Load Cells/Wheatstone Bridges

  Strain Gauges

  Temperature Sensors