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

Micro electro mechanical systems (MEMS) technology holds the promise of making complex systems that integrate micro mechanical and microelectronic component. MEMS gyroscopes can be implemented performance in a small package at a small cost, provide be high while being rugged and operable in harsh environments and take up less space than the macro-systems available. It is believed that MEMS gyroscope will soon be mass produced at similar volumes.The sensing system of micromechanical silicon gyroscope is designed on the base of the differential capacitance sensor's work principle. The sensing circuit tuning fork micromechanical gyroscope is designed. As for the detecting circuit of the capacitances, the "charge sense" circuit is designed. Trough the analysis of the output of the detecting circuit of the capacitances, the processing circuit is designed. Use locked-in amplifier technology to detect weak signal. In first amplifier, using high impedance and low noise operational amplifier. Then two-pole band-pass filter, a single-pole low-pass filter and transfer-phase circuit are designed. Then the angular rate is separated. Parameters computed of the gyroscope and the performance analyzed of the circuit show that the circuit can reach the base requirement.At last, the layout of the sensing system of micromechanical silicon gyroscope is finished with BiCMOS technology and complemented with series of check.