MASH2-0 ELECTROMECHANICAL SIGMA-DELTA MODULATOR FOR CAPACITIVE MEMS SENSORS WITH DIGITAL FILTER CALIBRATION USING SIMULATED ANNEALING

In this paper, an electromechanical multi-stage noise-shaping (EM-MASH2-0) structure that employs the dual quantization technique is presented. The advantages of an EM-MASH compared to the single-loop sigma-delta modulators (Sigma Delta M) applied to inertial MEMS sensors are its inherent stability, high overload input, high dynamic range, and high noise-shaping performance. The drawback of EM-MASH is its sensitivity to variations in system parameters. To overcome this problem, a digital calibration technique is presented that uses the Simulated Annealing (SA) optimization method, in which the digital domain of the system is utilized. The study confirmed the ability of the SA to identify system parameters and restore the performance of EM-MASH to its optimum level with a noise floor of around -127 dB.