基于前馈gmf的共模反馈稳定性增强电路  

A CMFB Loop Stability Enhancement Circuit Based on Feedforward Path gmf

作　　者：唐晓柯 胡毅 侯佳力 邓恒 孟昊 汪宇怀 李靖[2] TANG Xiaoke;HU Yi;HOU Jiali;DENG Heng;MENG Hao;WANG Huaiyu;LI Jing(Beijing Smartchip Microelectronics Technology Company Limited,Beijing100192,P.R.China;School of Electronic Science and Engineering,University of Electronic Science and Technology of China,Chengdu 610054,P.R.China;State Grid Zhejiang Electric Power Company,Ltd.,Hangzhou 310007,P.R.China)

机构地区：[1]北京智芯微电子科技有限公司,北京100192 [2]电子科技大学电子科学与工程学院,成都610054 [3]国网浙江省电力有限公司,杭州310007

出　　处：《微电子学》2022年第3期406-411,共6页Microelectronics

基　　金：国网总部科技项目(5700-202041261A-0-0-00)。

摘　　要：基于0.13μm CMOS工艺,提出并设计了一种应用于三级全差分运算放大器中的新型共模反馈电路。将具有密勒补偿结构的典型两级全差分结构和源随器结构作为三级运算放大器的放大级,通过在共模反馈电路中引入前馈通路,产生的两个零点提高运放的稳定性,解决了传统共模反馈电路中多个极点难以补偿的问题。仿真结果表明,在1.2 V电源电压下,共模下增益为70.4 dB,单位增益带宽为56 MHz,相位裕度为85.5°。相比于传统无前馈电路,新型共模反馈电路的单位增益带宽和相位裕度分别提高了8.2 MHz和17.4°。具有这种共模反馈结构的运算放大器可以实现较低的电源电压和较好的相位裕度。Based on a 0.13 μm CMOS process, a new common-mode feedback circuit for three-stage fully differential operational amplifier was proposed and designed. A typical two-stage fully differential and source-follower structure with a Miller compensation structure was used as the amplification stage of the three-stage operational amplifier. By introducing a feedforward path in the common-mode feedback circuit to generate two zeros, the stability of the operational amplifier had been improved, which could solve the problem that multiple poles are difficult to compensate in the traditional common mode feedback loop. The simulation results showed that the gain was 70.4 dB, the unity gain bandwidth(GBW) was 56 MHz, and the phase margin was 85.5° under 1.2 V voltage. Compared with the traditional circuit without a feedforward path, the GBW and phase margin of the new common-mode feedback circuit were increased by 8.2 MHz and 17.4° respectively. An operational amplifier with this common-mode feedback structure could achieve lower power supply voltage and better phase margin.

关 键 词：共模反馈 前馈通路 三级全差分运算放大器 频率补偿 

分 类 号：TN722.1[电子电信—电路与系统] TN432