Reset Noise Sampling Feedforward Technique (RNSF) for Low Noise MEMS Capacitive Accelerometer

The reset noise sampling feedforward (RNSF) technique is proposed in this paper to reduce the floor of readout circuit for micro-electromechanically systems (MEMS) capacitive accelerometer. Because technology-imposed size restriction on sensing element, capacitance and variation are reduced femto-farad level. As a result, from parasitic capacitance, which pico-farad level, becomes significant. In work, RNSF focuses suppression parasitic-capacitance-induced noise, thereby improving performance MEMS simulation results show that effectively suppresses thermal capacitance. Compared with traditional circuit, by 9 dBV. presented based fabricated commercial 0.18-μm BCD process tested physical measurement that, compared without technique, reduces accelerometer −72 dBV −80 other similar works, achieves better FoM (FoM=(power×noise floor)/system bandwidth=490 μW·μg/Hz) among switched-capacitor circuits.