A High Precision CMOS Opamp Suitable for ISFET Readout  

一种适用于ISFET读出的高精度CMOS运放设计(英文)

作　　者：张翀[1] 杨海钢[1] 魏金宝[1] 

机构地区：[1]中国科学院电子学研究所

出　　处：《Journal of Semiconductors》2008年第4期686-692,共7页半导体学报（英文版）

基　　金：国家自然科学基金资助项目(批准号:90307014)~~

摘　　要：This paper presents a high precision CMOS opamp suitable for ISFET readout. The opamp is tailored to provide a constant bias condition for ISFET as part of the readout circuits and,hence,is compatible for single chip integration with the sensor. A continuous time auto-zero stabilization technique is studied and employed, with the aim of suppressing the low frequency noises, including the offset voltage, 1/f noise, and temperature drift. The design is based on a 0.35μm CMOS process. With a 3.3V power supply,it maintains a DC open loop gain of more than 100dB and an offset voltage of around 11μV,while the overall power dissipation is only 1.48mW. With this opamp, a pH microsensor is constructed, of which the functionality is verified by experimental tests.介绍了一种适用于ISFET读出的高精度CMOS运放设计.该运放可为ISFET提供恒定电流、电压偏置,从而便于构建读出电路并于微传感器单片集成.通过运用连续时间自调零技术,大大降低了运放的失调电压、1/f噪声和温漂等低频噪声.该设计基于0.35μm CMOS工艺,电源电压3.3V,运放的开环增益超过100dB,输入等效失调电压低至11μV,总功耗仅为1.48mW.应用该运放实现的pH微传感器已通过实验验证.

关 键 词：high precision auto-zero operational amplifier ISFET microsensor 

分 类 号：TN722.77[电子电信—电路与系统]