电容式压力传感器微电容测量集成电路的研制

Development of IC for Measuring the Micro-Capacitance of Capacitive Pressure Sensors

采用开关电容技术的Boxcar(时域平均)积分原理设计,为测量电容式压力传感器的微电容的接口电路已提出。它由Boxcar积分器,锁存器,脉冲宽度调制器和控制信号电路组成。该接口电路,采用3μm P-阱CMOS双层多晶硅栅工艺研制,管芯面积为2.5mm×3.5mm.测试结果表明,接口电路具有较好的灵敏度,它能将硅集成电容式压力(加速度)传感器集成在同一芯片上,实现一体化。

A interface circuit for measuring the micro-capacitance of capacitive pressure sensors is proposed, which is based on Boxcar (time domain average) integration principle of the switched capacitor technology. It consists of a Boxcar integrator, a latch, a pulse-width modulatior and a signal control circuit. The interface circuit is developed and fabricated with 3μm P-well bilayer-polysilicon grid CMOS technique. The die area is 2.5mm × 3.5mm. The testing results show that the circuit has good sensitivity and the silicon capacitive pressure (acceleration) sensor can be integrated on the same chip. Integration is realized.