OFFSET AND NOISE REJECTION ANALYSIS IN CMOS PIEZORESISTIVE SENSORS

Abstract: In this paper, the use of piezoresistive CMOS beams is addressed with a particular focus on offset and noise rejection problems in a Wheatstone bridge. Using a test-chip (a magnetometer), the mismatch between resistors (on the substrate) and gauges (suspended) is experimentally studied. Both thermal and mechanical causes are analysed. Finally, mismatch cancellation techniques are reported