An offset-compensated switched-capacitor interface circuit for closed-loop MEMS capacitive accelerometer

Abstract

This paper presents a switched-capacitor readout circuit designed for the closed-loop MEMS capacitive accelerometer with a full scale of ±2g. The offset voltage of amplifiers is compensated and the low-frequency noise is reduced by using CDS technique, thus the precision of the whole system is significantly improved. The chip has been fabricated in a 0.35μm 15V CMOS technology and the equivalent noise acceleration (ENA) of the whole accelerometer system is tested to be 950ng/VHz at 120Hz in atmosphere.