一种消除共模反馈电流辅助放大的高增益运放  

A current-aided gain-boosted amplifier with common mode feedback canceling

作　　者：刘伟 孙正龙 黄东 商世广 LIU Wei;SUN Zhenglong;HUANG Dong;SHANG Shiguang(School of Electronic Engineering,Xi'an University of Posts and Telecommunications,Xi'an710121,China)

机构地区：[1]西安邮电大学电子工程学院,陕西西安710121

出　　处：《电子元件与材料》2021年第12期1261-1266,共6页Electronic Components And Materials

基　　金：陕西省自然科学基础研究计划(2020JM-583)。

摘　　要：提高放大器增益通常采用电压型辅助运放,但由于引入了共模反馈电路,增加了运放的复杂度,同时也增大了面积和功耗。基于此问题提出了一种消除共模反馈电流辅助放大的高增益运算放大器。此放大器主要由一个主放大器与两个电流辅助放大器构成,整体结构都采用了差分输入单端输出,消除了共模反馈电路。同时电流辅助放大器结构简单,减小了电路面积,降低了功耗。输出级对传统AB类放大器进行了改进,实现了轨到轨电压的输出。电路采用0.35μm CMOS工艺实现,运用Candence软件进行仿真。仿真结果表明,在5 V电源电压下,开环增益为167.5 dB,相位裕度为70°,电源抑制比(PSRR)为128 dB,共模抑制比(CMRR)为138 dB。To increase the gain of an amplifier,a voltage-type auxiliary op amp is usually used.However,the introduction of a common mode feedback circuit often causes complexity of the op amp and increases the area and power consumption.As a result,this article proposed a current-aided gain-boosted amplifier with common mode feedback canceling.This amplifier was mainly composed of a main amplifier and two current auxiliary amplifiers.The overall structure adopted differential input and single-ended output,eliminating the common mode feedback circuit.At the same time,the current-assisted amplifier had a simple structure,which reduced the circuit area and power consumption.The output stage was improved from the traditional class AB amplifier to achieve the rail-to-rail voltage output.The circuit was implemented in 0.35μm CMOS technology and simulated by Candence software.The simulation results show that the open-loop gain is 167.5 dB,the phase margin is 70°,the PSRR is 128 dB,and the CMRR is 138 dB under 5 V supply voltage.

关 键 词：高增益 增益增强 电流放大器 共模反馈 轨到轨 

分 类 号：TN722.77[电子电信—电路与系统]