A 104dB SNDR Transimpedance-based CMOS ASIC for Tuning Fork Microgyroscopes

A CMOS ASIC has been designed and interfaced with a high Q MEMS gyroscope to yield an angular rate sensor with a 1.2deg/hr noise floor and 2mV/deg/s rate sensitivity. A T-network transimpedance amplifier (TIA) has been implemented with a measured capacitive resolution of 0.04aF/radicHz, an SNDR of 104dB and which consumes ~ 400muW of power. The TIA also provides large on-chip transimpedance and can sustain oscillations in MEMS gyroscopes with motional impedances greater than 100MOmega