Design of a High Precision Integrated charge detection circuit based on Quartz Gyroscope

摘要

Used Three-stage op amp to design a good performance CMOS integrated charge detection based on quartz gyroscope. In the circuit design, using the PMOS full-differential input and the folded cascade structure, through adjusting the transistor parameters to reduce noise and improve the gain; Set each transistor's parameters based on 0.5μm CMOS process, use H-Spice software in detection circuit and demodulation circuit for simulation, parameter adjustment and verification. The simulation results contain: the open-loop gain gets to 128.13dB, phase margin 88°, SR gets to 2V/μs, the output noise is 38nV/ HZ at 10kHz frequency, full output swing. The simulation results of output signal show that each 5°C10~(-15)C change of input charge amount can provide about 1mV change of output voltage. The voltage signal that obtained by the demodulation circuit compares with the input angular velocity signal has a very highly linearity.