Research on High-Precision and Low-Power Quartz MEMS Gyroscope Signal Demodulation Circuit Based on AFE and FPGA Fusion

Mainstream quartz MEMS gyroscope signal demodulation methods are coherent demodulation methods, and the sensitivity of phase limits their accuracy improvement. In order to improve the accuracy of quartz MEMS gyroscope signal demodulation and achieve low-power gyroscope signal demodulation, a high-precision and low-power quartz MEMS gyroscope signal demodulation circuit based on AFE and FPGA fusion is proposed: The FPGA circuit uses simplified non-phase-sensitive amplitude discrimination algorithm and second-order IIR low-pass filter to build demodulation circuit; The AFE circuit uses low-power single point DFT algorithm based on CORDIC algorithm for demodulation. Then performs dual circuit fusion to improve demodulation accuracy. The high-precision quartz MEMS gyroscope signal demodulation circuit is achieved with a scale factor of 6.4 mV/°/s, relative error of 1.14%, and data variance of 0.39. By detecting the rate of change in angular velocity, it switches to a single circuit to achieve low-power signal demodulation goals, the minimum operating power consumption is about 79mW.