A versatile analog front-end for sensors based on piezoresistive silicon nanowire detection

We present the design and implementation of an analog front-end for smart-sensors and measurement results with prototypes of acceleration micro-sensors. The technology used for sensor manufacturing features silicon nanowires as strain gauges. The proposed system supports Kelvin contacts scheme and sensor bias duty-cycling. A fully-differential amplifier with a sensor-degenerated common-mode rejection scheme implements sensor bias and readout with current re-use. Experimental results for the fabricated analog-front-end show a -89 dB non-linearity, a dynamic-range higher than 73 dB over the 1 mHz to 500 Hz bandwidth taking into account for sensor noise, a 540 mA consumption and operation at 1.7 V supply.