Design of a High Precision Integrated Charge Detection Circuit Based on Quartz Gyroscope
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 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/ at 10kHz frequency, full output swing. The simulation results of output signal show that each 5×10-15C 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.
Y. J. Cao et al., "Design of a High Precision Integrated Charge Detection Circuit Based on Quartz Gyroscope", Advanced Materials Research, Vols. 317-319, pp. 1143-1148, 2011