一种低电压恒定跨导Rail-to-Rail的CMOS运放输入级  

A Low-Voltage Constant-gm Rail-to-Rail CMOS Operational Amplifier Input Stage

作　　者：路延[1] 姚若河[1] 

机构地区：[1]华南理工大学微电子研究所,广州510640

出　　处：《电子器件》2008年第5期1479-1482,共4页Chinese Journal of Electron Devices

摘　　要：提出了一种采用了四对差分管来实现跨导恒定的Rail-to-RailCMOS运算放大器输入级的方法。用两对互补的差分对作为输入级,另两对互补差分对动态地控制输入级工作电流,以实现Rail-to-Rail恒定跨导。通过在电路中加入补偿电流来提高四对差分管工作的协调性。基于TSMC0.18μmCOMS的工艺,应用Hspice在不同电压、温度环境下进行了电路的仿真验证,结果表明所设计的电路在各种条件下都有较好的性能,其在共模范围内跨导最大偏差小于2%。本文还分析了MOS管二阶效应对电路产生的影响。This paper presents a rail-to-rail eonstant-gm operational amplifier input stage by using four differential pairs. Two differential pairs are used as input differential pairs, the other two dummy differential pairs are used to change the tail current of the input differential pairs dynamically for a constant-gm. Compensate current sources are added to the tail current transistors of each dummy input differential pairs for lower gm variation. The circuit is designed in TSMC 0. 18μm CMOS technology, and simulated under different supply voltages and temperatures by using Hspice. The performance of the circuit under different conditions is goo＆ The gm of this Op Amp＇s input stage varies around ± %. The Second order effect of MOSFET have been taken into consideration.

关 键 词：RAIL-TO-RAIL 运算放大器 电流补偿 

分 类 号：TN722.77[电子电信—电路与系统]