Multi Stage Noise Shaping Sigma-delta Modulator (MASH) for Capacitive MEMS Accelerometers

Electromechanical multi stage noise shaping sigma-delta modulator (MASH) has the advantages of inherent stability, high dynamic range, and high overload input level compared with the single loop sigma-delta-modulator approach. In this paper, a fourth order electromechanical MASH is studied by Simulink modeling and hardware implementation using surface mount PCB technology. The accelerometer used in the study is fabricated using a Silicon on Insulator (SOI) wafer with a device layer thickness of 50um, using a dicing free and dry release process. The experimental results confirm the concept of the MASH structure and show its potential as a closed loop interface concept for a high performance capacitive MEMS accelerometer. (C) 2011 Published by Elsevier Ltd.