折叠共源共栅放大器的零极点分析

哈尔滨理工大学学士学位论文--I折叠共源共栅放大器的零极点分析摘要运算放大器是模拟集成电路中最重要的单元电路，在各种模拟电路和数模混合电路中得到了广泛的应用。近年来，以电池作为电源的微电子产品得到了广泛使用，因而对放大器性能的要求亦逐渐增加。通过分析零极点可以分析出放大器工作特性，零极点的分析需要借助传输函数，在传输函数中，取其分子为零，可得零点，取其分母为零，可得极点，而传输函数则需要通过分析小信号模型等效电路得到。零点、极点可以看成是电路分析中抽象出来的辅助方法，因而可以通过零极点分析电路动作特征。本论文主要研究折叠共源共栅放大器的零极点产生机理，对于放大器的零极点而言，其产生跟放大器的寄生电容，以及本身需要的节点与节点之间的电容，还有负载电容跟电阻有关。当电容或者电阻发生变化时会影响到放大器的工作特性。基于以上原理，本文简要分析了当放大器输出端加载一个大负载电容，在放大器进入稳定工作状态瞬间，其输出端会产生一个尖峰电流，这种电流的存在会影响电路的正常工作。本文运用运放零极点相关原理和解决手段，根据分析这种现象的原因是，极点发生变化，为了抑制极点变化，可以在运放输出端与负载电容之间加载一个电阻，让该电阻与负载电容组成STC网路，分离极点。关键词放大器；零极点；尖峰电流哈尔滨理工大学学士学位论文-II-Pole-zeroAnalysisOfFoldingCommon-sourceAndCommon-gateAmplifierAbstractAnalogICopampisthemostimportantunitcircuit,hasbeenwidelyusedinvariousanalogcircuitsanddigital-analoghybridcircuit.Inrecentyears,thebatteryasapowersourcemicroelectronicproductshavebeenwidelyused,andthustheamplifierperformancerequirementsarealsoincreasing.Byanalyzingthepole-zeroamplifieroperatingcharacteristicscanbeanalyzed,pole-zeroanalysisneedsthetransferfunction,thetransferfunction,whichevermoleculeiszero,wegetzerowhicheverdenominatoriszero,wecangetthepole,andthetransferfunctionisrequiredByanalyzingsmall-signalequivalentcircuitmodeltoget.Zero,polecircuitanalysiscanbeseenasanauxiliarymethodintheabstract,itispossibleactionbythepole-zeroanalysiscircuitcharacteristics.Inthisthesis,atotalcommon-gateamplifierfoldedpole-zerosourcegenerationmechanism,thepole-zeroamplifier,itscapacitanceisgeneratedbetweentheparasiticcapacitancewiththeamplifier,andthenodewiththenodeitselfneeds,aswellastheloadcapacitancewithresistancerelated.Whenthecapacitanceorresistancetochangewillaffecttheoperatingcharacteristicsoftheamplifier.Basedontheaboveprinciple,thepaperanalyzes,andwhentheoutputoftheamplifiertoloadalargeloadcapacitance,theamplifierintothesteadystatemoment,itsoutputwillgenerateapeakcurrent,thepresenceofthiscurrentwillaffectthenormaloperationofthecircuit.Inthispaper,thepole-zeroopamprelevantprinciplesandmeansofsettlement,accordingtotheanalysisofthereasonsforthisphenomenonisthatthepolechanges,inordertosuppressextremechangesintheoutputofopampbetweentheloadandtheload哈尔滨理工大学学士学位论文-III-capacitanceofaresistor,sothattheresistanceandtheloadcapacitorsSTCnetwork,separatepoles.KeywordsAmplifiers,Pole-zero,Peakcurrent哈尔滨理工大学学士学位论文-IV-目录摘要......................................................................................................................IAbstract..............................................................................................................II第1章绪论........................................................................................................11.1课题背景...................................................................................................11.2课题研究的目的和意义...........................................................................11.3课题的主要任务及章节摘要...................................................................11.4本章小结...................................................................错误!未定义书签。第2章CMOS运算放大器的设计基础...........................................................42.1电路设计的基本原理................................................................................42.1.1运放大电流控制基本原理................................................................42.1.2电流比较器基本原理........................................................................42.2MOS器件原理及模型................................................................................52.2.1MOS管的大信号模型.......................................................................52.2.2MOS管的二级效应...........................................................................72.2.3MOS管的小信号模型.......................................................................82.3运算放大器概况及分类..........................................................................102.3.1简单的共源共栅放大器...................................................................122.3.2套筒式共源共栅运算放大器...........................................................162.3.3折叠式共源共栅运算放大器...........................................................182.4折叠共源共栅放大器输出级设计..........................................................232.5本章小结..................................................................................................24第3章电路设计分析......................................................................................253.1设计指标..................................................................................................253.2折叠共源共栅放大器的极点分析..........................................................253.3折叠共源共栅放大器的零点分析..........................................................273.4运放上电过程中的电流分析及极点分析.............................................283.5抑制零极点漂移方案.............................................................................293.6本章小结.................................................................................................30第4章电路仿真..............................................................................................314.1放大器增益..................................................................................