Design of analog front-end readout circuit for capacitive silicon micro gyroscope

Abstract

To design a high-performance analog front-end readout circuit for capacitive silicon micromachined gyroscope, this paper presents electrical modeling of the silicon micromachined gyroscope according to its working characteristics, proposes to construct the amplitude and frequency range of the silicon micromachined gyroscope signal in the form of a capacitor array, and designs the capacitance readout circuit of the gyroscope based on this model. Based on the SMIC 0.18 um CMOS process, the electrical model and its capacitance readout circuit are designed and simulated in this paper. The results indicate that the capacitance readout circuit can accurately detect the equivalent variable capacitance signal of the gyroscope electrical model and transform it linearly into a voltage signal. The equivalent output noise of the overall analog front-end readout circuit is 80.11 nV/√Hz@6.4kHZ. The system resolution can reach 0.29 aF. As a result, the silicon micro gyroscope analog front-end circuit has a wide range of capacitive applications, high linearity, low noise, and broad market and application prospects. Hence, this topic is of great scientific significance.