Design of a micropower signal conditioning circuit for a piezoresistive acceleration sensor

The design and test of a micropower signal conditioning circuit for a piezoresistive accelerometer is presented. The circuit is intended for sensing human body motion in rate-adaptive cardiac pacemakers. A strategy is proposed to allow handling of the piezoresistive sensor with the desired level of consumption. Experimental results show the fabricated circuit is able to measure accelerations in the range from 0.04 g to 0.34 g with a total consumption of less than 3 /spl mu/A with supply voltages down to 2 V.