Design of an interface circuit for integrated capacitive sensors

In this paper, an interface circuit for integrated capacitive sensors is designed and simulated by Spectre of Cadence software with TSMC 0.18μm complementary metal oxide semiconductor (CMOS) process. This circuit converts the capacitance of sensing capacitor to the voltage change based on switched-capacitor circuit. The results show the sensitivity of 1mV/10fF and the circuit removes the effect of bias voltage and amplifier offset, decreases the influence of charge injection and clock feed through.