关键词: 模拟开关, CMOS, 漏电流补偿技术, 信号采集系统, PN结漏电

Abstract: In order to meet the ultra-high precision signal acquisition needs of various modern equipment control systems, an ultra-low leakage analog switching circuit is designed based on a new PN junction leakage compensation technology. Based on the traditional CMOS analog switch, the new PN leakage sampling and compensation circuits in full temperature range are innovatively introduced to compensate the input and output leakage current of the CMOS analog switch, greatly reducing the leakage current of input and output ports and achieving the port current of sub-nA level. Based on 40 V high voltage CMOS process for circuit design and simulation verification, the measured results show that in the range of -55 ℃ to 125 ℃,the leakage currents of the input and output ports are not more than 0.75 nA, and the temperature drift is about 6 pA/℃.

Key words: analog switch, CMOS, leakage current compensation technology, signal acquisition system, PN junction leakage current