chopping technology and capacitive adaptive calibration technology
a low noise
high dynamic range fully differential capacitive MEMS accelerometer detection circuit is designed. Capacitive adaptive calibration technology is used in detection circuit sensing capacitance to eliminate the capacitance mismatch and improve the detection range. Chopper is added to the switched capacitor low-pass filter to reduce the filter noise. The filter timing is controlled to eliminate the non-linearity caused by charge injection. Under the 5 V power supply
the simulation results show that the output linear voltage range of the detection circuit is ± 3 V
in the range of 0. 01 ~ 300 Hz
the equivalent output noise is 650 n V
and the detection dynamic range is higher than 120 d B.