全差分运算放大器中共模稳定性的分析  

Common Mode Stability in fully differential Operational Amplifiers

作　　者：汤益明[1] 万培元[1] 郭乐乐[1] 郎伟[1] 林平分[1] 

机构地区：[1]北京工业大学北京市嵌入式系统重点实验室,北京100124

出　　处：《中国集成电路》2012年第5期22-25,共4页China lntegrated Circuit

摘　　要：本文提出了用在增益可调放大器中,差分电压放大器中共模反馈稳定性的分析。本文分析了在差模运算放大器中内部共模反馈电路(CMFB)和外部由电阻构成的正反馈网络。共模反馈电路用来确保运算放大器的稳定性,外部的正反馈网络需要留心防止"锁死状态"。本文的运放采用折叠式共源共栅结构,用SMIC0.18μm混合信号工艺进行流片。Design considerations are presented for stabilizing the common-mode feedback （ CMFB ） loop in fully differential voltage feedback CMOS amplifiers used in programmable gain Control amplifiers. After considerations in designing a balanced differential operational amplifier, internal CMFB circuitry and external feedback network are investigated. The former insures the amplifier stay stability, and the latter should be carefully to avoid ＇latching states＇ . cascade circuit implemented in 0.18urn CMOS mixed signal process of SMIC is presented, based on a folded topology

关 键 词：差分运算放大器 共模反馈(CMFB) 正(负)反馈 两个反馈环路 锁死状态 

分 类 号：TN722.77[电子电信—电路与系统]