A Low-noise CMOS Readout Circuit for Capacitive Micro-sensors

In this paper, we combined chopper stabilization (CHS) and correlated double sampling (CDS) techniques to remove the parasitic capacitance of MEMS sensor and the noise from the readout electronic circuit. The presented readout circuits can be integrated easily with MEMS sensors using a modern CMOS processes for batch production. The present CMOS-MEMS system is fabricated using a 0.35 mum 2P4M CMOS process. Simulation results indicated that the sensing circuits can achieve a low noise floor 0.0012 aF/radicHz and a low power consumption 19.14 mW with a sampling frequency of 4 MHz.