The Study And Realization Of The Driving System Of Micromechanical Silicon Gyroscope

Along with the development of the modern physics, microelectronics, computer and inertial technology, the micromechanical gyro with its unique characteristics has become a development trend for inertial sensor and it possesses a good application prospect. The silicon micromechanical gyroscope with the advantages of small size,simple structure, low price and easy integration plays an important role in the military, civil and automotive industry.The aim of this thesis is to find out the electrostatic driving system of a silicon micromechanical tuning-fork vibratory gyroscope. The closed-looped driving system is designed on the base of the differential capacitance sensor's work principle. Two polysilicon sensing structures each contain a quality mass, which is electrostatically driven to resonance. This produces the necessary velocity element to produce a Coriolis force during angular rate. Movable fingers are placed between fixed pickoff fingers to form a capacitive pickoff structure which is called comb resonator. The electrostatical driving ciruit mainly consisting of charge amplifier, band pass filter, latched comparator, charge pump, driving output interface and dc source circuits are designed and analysed. The performance analyzed of the circuits and the simulation results showed that these circuits can reach the base requirement. At last, the layout of processing circuit is finished with BiCMOS technology and complemented with series of varification.