An s-z domain transformation method for the readout circuit design of closed-loop micromechanical capacitive accelerometer

Matlab/Simulink tool has been widely used in system modeling of circuit design. However, its application in the discrete-time circuit is not enough mature. Based on the continuous-time circuit simulation results by Matlab/Simulink, an s-z transformation method for the discrete-time accelerometer system design is proposed in this paper. In this method, a switched-capacitor readout circuit for closed-loop micromechanical capacitive accelerometer is designed and fabricated in a 0.35µm 15V CMOS process. The accelerometer operates under ±6.5V supply with a full scale of ±50g and the equivalent noise acceleration (ENA) is tested to be 54µg/√Hz at 60Hz.