摘要
分析了传感器微电极产生信号的特点,阐述了读出电路的工作原理和设计要点,采用电流转换为时间的方法实现了弱信号的读出,最小可测量1 pA的直流电流,量程达5个数量级,相对误差小于0.1。并且系统自带10位数字信号输出,避免了使用AD转换器带来的功率和空间的消耗。系统采用Chartered 0.35μm标准CMOS工艺流片。
The characteristics of the signal from the sensor＇s microelectrodes are analyzed. A weak current readout circuit is designed, which uses a method of transferring current signal into time one. Current ranging from 1 pA to 100 nA can be measured with a maximum relative deviation of 0. 1. The system also delivers a 10 bit digital output, which avoids use of an extra analog-to-digital converter. This way, power and space of the chip can be further reduced. The chip has been fabricated in the 0. 35um Chartered CMOS process. Experimental results are reported, characterising the performance of the system as an electrochemical sensor.
出处
《电子器件》
EI
CAS
2006年第4期1090-1093,共4页
Chinese Journal of Electron Devices
基金
国家自然科学基金资助重点项目(90307014)
