The Design and Implementation of Interface Electronics for Silicon Micromechanical Gyroscopes

This chapter reports the design and implementation of interface electronics for the silicon micromechanical gyroscope with electrostatic excitation and capacitive detection. In the proposed electronics, the charge amplifier is used for the capacitance readout, and the phase feedback loop and the direct-current feedback loop are applied to drive the drive axis at resonance with constant vibration amplitude. To obtain the input angular rate, the demodulator based on the phase-locked-amplifier is utilized. The electronics system comprises few analog parts (capacitance readout circuits) and the digital part based on FPGA is implemented and its performance is tested. The results show that the scale factor is 13.4 mV/(°/s) with a 46 ppm nonlinearity in the measurement range of ±150°/s and the noise floor is 0.002°/s/√Hz.