Abstract:Due to the limitation of processing technology and testing environment, the parasitic feedthrough capacitance is inevitably introduced in the micro gyroscope prepared using MEMS technology, which seriously interferes with signal detection. However, the commonly used feedthrough cancellation methods highly depend on the symmetry of the micro gyroscope and the detection circuit, which cannot effectively eliminate the feedthrough signal. In order to solve the problems, a new feedthrough cancellation method is proposed in this paper. The feedthrough effect is analyzed by establishing an RLC equivalent circuit model including the feedthrough capacity. Then, a fully differential feedthrough cancellation scheme combined with two inverse feedthrough cancellation circuits is proposed. Two inverse feedthrough cancellation circuits are designed to adjust the errors caused by the asymmetry of the differential path. This method can effectively eliminate the feedthrough signal while improving the drive force. Taking the square mass vibratory micro gyroscope as the research object，the signal-to-noise ratio (SNR) of the detection signal after feedthrough cancellation of this method is 25.57 dB, which is 13.32 times higher than the SNR before feedthrough cancellation. The test results show that this method can effectively compensate for the feedthrough current and improve the signal detection performance of the micro gyroscope.