A MEMS Capacitance Accelerometer Readout Circuit with Ring-Diode Detection

In this paper, a thorough theoretical analysis for ring-diode based differential capacitance accelerometer readout circuit was carried out. Based on this theoretical model, a gain algorithm based on the principle of minimizing circuit charge leakage was proposed, and a numerical simulation of the relationship between circuit parameters and the output amplitude response of the readout circuit was presented. According to the simulation results, a readout circuit parameters optimization method was demonstrated. The experimental results show that the effect of circuit parameters on the output voltage was basically consistent with the numerical simulation. The adopted accelerometer readout circuit in this paper is implemented with a standard 0.18-μm CMOS process, and the optimized detection sensitivity of the readout circuit is about 64.40mV/pF.