恒跨导高摆率轨对轨运算放大器的设计  

Design of constant-gm and high-slew-rate rail-to-rail operational amplifier

作　　者：张伟娟[1] 邹伟[1] 徐坤玉[1] 

机构地区：[1]兰州交通大学电子与信息工程学院,甘肃兰州730070

出　　处：《电子测试》2011年第11期58-61,共4页Electronic Test

基　　金：甘肃省自然科学基金资助项目(1010RJZA065)

摘　　要：本文在分析MOS管恒跨导输入级和AB类输出级运算放大器的基础上设计了一个高摆率、恒跨导的轨对轨运算放大器。在输入级中采用了齐纳二极管的稳压原理,保证Rail-to-Rail运算放大器的输入跨导恒定。为了实现高转换率,本文采用了一种新型的压摆率提高电路。另外,为了提高系统的稳定性,采用了控制零点的米勒补偿进行频率补偿。采用CSMC 0.5 μm CMOS工艺,用H-Spice对整个运算放大器电路进行仿真验证,结果表明运算放大器输入输出范围基本达到满摆幅,最大跨导变化率仅为3.9%和具有较高的增益和摆率。Based on analyzing MOS transistor constant-gm input stage and class AB output of operational amplifier, a high-slew-rate and constant-gm, rail-to-rail operational amplifier was designed. A Zener-diode structure was inserted in the input stage to keep the gm of the input stage constant. A novel slew rate enhancement circuit was implemented to achieve a high slew rate. In addition, the miller compensation was adopted to improve the stability of the system. The circuit was realized in CSMC 0.5 μm CMOS process and is simulated by H-Spice for whole of operational amplifier. The simulated results showed that the operational amplifier has rail-to-rail input and output and the maximum gm fluctuation is only 3.9%. It has quality of high gain and rate.

关 键 词：恒跨导 轨对轨运算放大器 摆率 

分 类 号：TN722.77[电子电信—电路与系统]