Differential pickup circuit design of a kind of Z-axis MEMS quartz gyroscope

Abstract The MEMS quartz gyroscope is composed by a tuning fork and the detection circuits. The tuning fork's error noise of a quartz gyroscope will have significant influence on it's performance. The mechanical coupling error noise still existed after design and processed, normally this kind of error noise can be reduced by some other methods such as laser trim, but the capacitor coupling error noise can’t be reduced by these methods. This paper introduces differences between error sources of a kind of z-axis quartz gyroscope and y-axis quartz gyroscope. The capacitor error noise of z-axis quartz gyroscope is larger than that of y-axis quartz gyroscope. According to characteristics of z-axis quartz gyroscope's coupling error noise signal, the differential and phase compensation circuit is designed, which can effectively remove the influence of tuning fork's error noise on the z-axis quartz gyroscope's signal, and can effectively improve the z-axis quartz gyroscope's performance.