Theoretical model of performance of a silicon piezoresistive pressure

This paper will describe briefly the two kinds of signal-conditioning interfaces of silicon piezoresistive pressure sensors: hardware compensation and software compensation. A detailed model of the accuracy budget for both approaches is explained. It will be shown that the device-to-device variations of the temperature coefficient of offset are a critical element, and that a calibration of this coefficient is unavoidable to get an accuracy of about 1% full scale. It will also be demonstrated that the ADC resolution is the key parameter in a software-compensation approach, and that the resolutions of the feedback loops for offset and gain adjustments are the key parameters in a hardware approach. When the sensor interface is optimized, the performance depends on the sensor non-linearity and on the temperature-reading error.