In view of the requirements of low voltage and low￣power consumption for portable and wireless devices,a new low￣voltage and low￣power interface circuit for CMOS micro￣capacitive sensor is designed based on the TSMC 0.18 μm CMOS technology,where the sensitive capacitor,the reference capacitor and the interface circuit itself are integrated on a single chip. The interface circuit can convert the variation of capacitance,which is sensitive to hu￣midity,into the width change of square pulse linearly and output digital values directly. Simulation results demon￣strate that the power consumption is only 1.95 mW and the conversion sensitivity can run up to 4.38 μs/pF at a supply voltage of 1.5 V. Comparing with the existing similar interface circuits,ours has the merits of good conversion linearity,low capacitance mismatch,insensitive to the change of temperature and process corner,etc.%针对便携、无线设备的低电压、低功耗需求，基于TSMC 0.18μm CMOS工艺设计提出一种面向CMOS微电容式传感器的接口转换电路。将敏感电容、参考电容与接口电路集成于同一芯片，可以将对湿度敏感的电容变化量线性转换为方波脉冲信号的宽度，并直接输出数字信号。实验仿真结果显示在1.5 V电源供压下电路消耗的功耗仅为1.95 mW，转换分辨率达到4.38μs/pF，与同类接口电路相比具有线性度好、有效减少电容间失配和对温度与工艺角变化不敏感等优点。
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