A Sub-0.1 degrees/h Bias-Instability Split-Mode MEMS Gyroscope With CMOS Readout Circuit

作者：Zhao, Yang^*; Zhao, Jian; Wang, Xi; Xia, Guo Ming; Shi, Qin; Qiu, An Ping; Xu, Yong Ping

来源：IEEE Journal of Solid-State Circuits, 2018, 53(9): 2636-2650.

DOI：10.1109/JSSC.2018.2844285

• Angle random walk (ARW)
• bias instability (BI)
• CMOS readout circuit
• demodulation phase
• inertial navigation
• low noise front end
• MEMS gyroscope
• temperature drift

This paper describes a split-mode tuning fork MEMS gyroscope with CMOS readout circuit. The gyroscope achieves 0.008 degrees/root h angle random walk (ARW) and 0.08 degrees/h bias instability (BI). The noise and phase requirements of the MEMS sensing element and the readout circuit are analyzed, from which the system-level design guidelines are proposed. The MEMS sensing element is optimized to enhance its mechanical sensitivity with reduced quadrature coupling and thermoelastic damping. Front ends with 5.9-fA/root Hz input-referred current noise floor and less than 0.5 degrees phase delay are achieved to reduce the gyroscope's ARW and thermal drift. A low flicker noise automatic amplitude control circuit and digitized phase-sensitive demodulation are adopted to improve the gyroscope's BI. After temperature compensation, the temperature coefficients (TCOs) of the scale factor and the zero-rate output are 27 ppm/degrees C and 1.7 degrees/h/degrees C from -40 degrees C to +60 degrees C, respectively. The overall power consumption is 8.5 mW under a 3.3-V supply.

• 出版日期2018-9
• 单位中国矿业大学（北京）; 清华大学; 南京理工大学