A LOW-NOISE HIGH-VOLTAGE INTERFACE CIRCUIT FOR CAPACITIVE MEMS GYROSCOPE

Abstract

This paper presents a high-voltage control and readout interface circuit implemented for capacitive Micro-Electro-Mechanic System (MEMS) gyroscope. A charge sensitive amplifier (CSA) with chopper technique is used to accomplish low-noise capacitive sensing. The stabilization of the closed drive loop is maintained by an auto gain controller (AGC) and an adjustable phase shifter. The outputs of the ASIC directly drive the gyroscope after buffered by an on-chip high-voltage level shifter. The chip is fabricated in a 0.35 um 5 V/12 V Bipolar, CMOS and DMOS (BCD) process. The test of the chip is performed with a MEMS vibratory gyroscope. The result shows that the Application Specific Integrated Circuit (ASIC) can ensure a stable oscillation in the drive axis, and the noise floor is 0.0015°/s/√Hz within 100 Hz.