MEMS Accelerometer Readout

You work in a characterization laboratory af a MEMS company, and you have to design an electronic board in order to test a given capacitive accelerometer. The application of the sensor is vibration monitoring on a mechanical engine in a specific frequency range (from 40 Hz to 400 Hz). The MEMS device has a mass of 8nK g , a mechanical stiffness of 5N /m and a quality factor Q = 2. The capacitive sensing is performed with 5 cells of differential parallelplate capacitors, each one with stators 200μm long. The gap between rotor and stators is 2.5μm and the process height is 15μm. The readout of the device is performed through a charge amplifier configuration stage, as the one represented in figure 1. The capacitance CP = 10pF takes into account the effects of capacitive coupling between rotor and substrate, pads and substrate, wire bondings and other causes.