CMOS ASIC for MHz silicon BAW gyroscope

Abstract

The paper reports a CMOS Interface IC designed for electrostatic actuation and read-out a 6 MHz Silicon Bulk Acoustic Wave (BAW) gyroscope. The supporting electronics for a high quality factor (Q>100,000) BAW gyroscope include: an electro-mechanical drive oscillator loop to excite the gyroscope, a low noise transimpedance front-end that offers gain of 126 dBOmega and 3-dB bandwidth of 26 MHz; and a Coriolis signal demodulator with minimum capacitance resolution of 0.014 aF/radicHz. The interface ASIC, a first for a high frequency BAW gyroscope, is fabricated in a 0.6 mum 2P3M CMOS process, occupies 2.25 mm2 and consumes 10.9 mW. The gyroscope system achieves a noise floor of 0.37deg/radichr/radicHz and rate sensitivity of 205 muW 7 sec.