A low-noise high-linearity interface ASIC for MEMS gyroscopes

Abstract

This paper presents a continuous-time analog interface ASIC for use in MEMS gyroscopes. A charge sensitive amplifier with a chopper stabilization method is adopted to suppress the low-frequency noise. In order to cancel the effect caused by the gyroscope capacitive mismatch, a mismatch auto-compensation circuit is implemented. The gain and phase shift of the drive closed loop is controlled separately by an auto gain controller and an adjustable phase shifter. The chip is fabricated in a 0.35μm CMOS process. The test of the chip is performed with a vibratory gyroscope, and the measurement shows that the noise floor is 0.003°/s/√Hz, and the measured drift stability is 43°/h. Within −300 to 300°/s of rotation rate input range, the non-linearity is less than 0.1%.