Damping ratio and natural frequency are key design parameters to improve the dynamic performance
of a micro-accelerometer. Considering the difficulty of improving the dynamic performance of current microaccelerometers by adjusting the mechanical damping, in this paper, an electrical damping based on a proportionalintegrative (PI) controller is introduced into the readout circuit to improve the dynamic performance of a capacitive micro-accelerometer. An equivalent mathematical model is established to describe the overshoot and setting time, and the proportional constant (P) ant the integrative constant (I)
are derived to obtain a rational damping ratio and natural frequency. The dynamic response of a bulk micromachined silicon accelerometer is experimentally measured and the results agree with the numerical simulations, indicating that the stability and the response speed can be improved by a proper combination of P and I of the controller.