Stability Analysis in High-Order Electromechanical Sigma-Delta Accelerometer

Abstract

A nonlinearity model including distortion components for sigma-delta (ΣΔ) accelerometer that allows stability analysis is described. Based on this model, closed-loop stability and signal dependent stability are analyzed detailedly. To verify the conclusions, Matlab/Simulink model for a fourth-order ΣΔ accelerometer is designed. The simulation results indicate that high-order system needs a large compensation coefficient, and it will not affect the performance due to the very high low-frequency gain of the loop filter. High-order system is conditionally stable, and stability is affected by the input signal.

Modeling and Analysis of a Closed-Loop System for High-Q MEMS Accelerometer Sensor

“…Traditional MEMS accelerometer system research is concentrated in open-loop with analog output [1]. Recently more research on high-Q MEMS accelerometer is focused on the closed loop system, mainly divided into analog and digital closed-loop [2][3][4]. Closed-loop with analog output makes quality block movement near the equilibrium position improving the linearity [5].…”