Coupled Electro-mechanical Simulation of Capacitive MEMS Accelerometer for Determining Optimal Parameters of Readout Circuit

Abstract

During the design of acceleration measuring system, the optimal choice of sensor parameters may only be made by careful analysis of both the MEMS sensor itself and the readout circuit. Therefore, a coupled electromechanical simulation is usually required. In this paper, we use such a simulation to determine the values of modulation voltage and switching frequency which ensure that the relative readout error is within acceptable limits. Three capacitive MEMS accelerometer structures are analyzed and the relative error due to the impact of electrostatic force is quantified. Based on these results, the recommendations about the optimal readout circuit parameters are given.