Low-Cost, 1%-Accurate Signal Conditioner for Piezoresistive Sensors

The MAX1450 sensor signal conditioner is optimized for piezoresistive sensor calibration and temperature compensation. It includes an adjustable current source for sensor excitation and a 3-bit programmable-gain amplifier (PGA). Achieving a total typical error factor within 1% of the sensor's inherent repeatability errors, the MAX1450 compensates offset, full-span output (FSO), offset 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 temperature 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.

Applications

* Hydraulic Systems * Manifold Absolute Pressure (MAP) Sensors * Piezoresistive Pressure and Acceleration Transducers and Transmitters

* 1% Sensor Signal Conditioning

* Corrects Sensor Errors Using Coefficients Stored in External Trimmable Resistors, Potentiometers, or DACs

* Compensates Offset, Offset TC, FSO, FSO TC, and FSO Linearity

* Rail-to-Rail Analog Output

* Programmable Current Source for Sensor Excitation

* Fast Signal-Path Settling Time (< 1ms)

* Accepts Sensor Outputs from 10mV/V to 30mV/V

* Fully Analog Signal Path

* Contains PGA, current source