Closed-loop Driving Circuit based on Frequency Modulation Method for Capacitive Micromachined Gyroscope

摘要

Closed-loop driving circuit is widely used in the high performance micrimachined gyroscope. But in the capacitive micromachined gyroscope, this circuit can be self-oscillation incapability because of signal coupling by parasitical capacitance. A novel closed-loop driving circuit based on the frequency modulation method is present in this paper. Since the frequency of driving signal is modulated, it is different from the frequency of sensing current. Even if there is coupling, the phase requirement of closed-loop driving method is not destroyed, which overcomes the disadvantage of self-oscillation incapability. Both the simulations and test results are provided, which demonstrates the feasibility of this method.