全差分套筒式共源共栅放大器及其共模反馈电路的研究

I论文题目：全差分套筒式共源共栅放大器设计及其共模反馈电路的研究II摘要随着便携式消费电子产品及各式各样智能设备的普及，如手机、智能手环、平板等。性能卓越的运算放大器是这些产品必不可少的组成部分。精确度高即为直流增益大（偏置处于微小的电流下，器件的尺寸长），速度高即为高单位增益带宽及单极点特性（偏置在大电流下，器件的尺寸短）。因此需要在参数中权衡、择优选取。一般来说，只有一级的运算放大器，如套筒式运算放大器，频率响应快，增益低；两级运放增益高，单位增益带宽不佳。在综合考虑以上因素后，设计一种全差分套筒式共源共栅放大器及其共模反馈电路的结构。在保证增益情况的优良情况下，使运放的频率响应具有单极点特性以此优化单位增益带宽。本文最初先简明扼要的阐述了MOS器件的基本工作原理，随后详尽分析、讲解了几种常见的运算放大电路结构，如基本的差动输入-差动输出结构、折叠式结构及套筒式结构，同时对其共模负反馈电路进行研究。将纷繁复杂的整体电路结构拆先分解为单一的电路模块，一步步进行设计、仿真、验证分析，再选择恰当的部分进行级联。经过电路仿真验证，放大器增益为64.46dB大于60dB,单位增益带宽为126.4MHz大于100MHz，连续型共模负反馈电路直流增益下降3.07dB小于5dB，离散型时钟频率为9.3MHz大于5MHz，从而完成所有电路设计参数指标，该电路设计可以正常工作。关键词：套筒式；全差分；共源共栅；共模反馈IIIAbstractAsportableconsumerelectronicproductsandavarietyofthepopularityofsmartdevices,suchasmobilephone,smarthandring,tablet,etc.Theexcellentperformanceofoperationalamplifieristheindispensablepartoftheproduct.Highprecisionisthedcgainlarge(biasinthetinyelectricalflow,thesizeofthedevice),highspeedistheunitgainbandwidthandunipolarpointfeatures(theoffsetinthebigpowerflow,thesizeoftheshort).Soitisnecessarytoweighintheparameterselectionandmerit.Ingeneralspeaking,onlythelevelofoperationalamplifiers,suchassleeveoperationalamplifiers,frequencyresponseisfast,lowgain;Twostageoperationalamplifiergainhigh,unitgainbandwidth.Afterconsideringtheabovefactors,todesignafully-differentialsharingsleevesourcegateamplifierandthestructureofcommonmodefeedbackcircuit.Inguaranteegainexcellentcases,thefrequencyresponseoftheop-ampsinglepolecharacteristicsinordertooptimizeunitgainbandwidth.ThisarticlefirstbrieffirstexpoundsthebasicworkingprincipleofMOSdevices,thendetailedanalysisandinterpretationofseveralcommonoperationalamplifiercircuitstructure,suchasbasicdifferentialinputanddifferentialoutputstructure,foldingstructureandsleevestructure,atthesametimetoresearchthecommon-modefeedbackcircuit.Dismantlethewholecircuitstructurecomplicated,firstbrokendownintoasinglecircuitmodule,thedesign,simulationandverificationanalysisstepbystep,andthenchoosetherightpartofthecascade.Throughthecircuitsimulation,amplifiergainof64.46dBgreaterthan60dB,unitgainbandwidthof126.4MHzismorethan100MHz,continuouscommon-modefeedbackcircuitdcgainfell3.07dBlessthan5dB,discreteclockfrequencyof9.3MHzismorethan5MHz,thuscompletingallcircuitdesignparameters,thecircuitdesigncanworknormally.Keywords:Telescopic、Fulldifferential、Cascode、CMFB目录摘要...................................................................................................................................IAbstract...............................................................................................................................III第1章引言....................................................................................................................1第2章MOS器件与运算放大器简介..............................................................................62.1MOS器件的工作原理及参数..............................................................................62.1.1MOSFET的结构.....................................................................................62.1.2MOSFET的输出特性................................................................................82.1.34种类型MOSFET的特性曲线小结.................................................102.2运算放大器的性能参数指标...............................................................................112.3典型运放对比...................................................................................................142.4本章小结..............................................................................................................16第3章运算放大器的设计............................................................................................173.1运算放大器的基本结构......................................................................................173.2两级运算放大器的设计方法..............................................................................183.3全差动运算放大器.............................................................................................213.4套筒式共源共栅运算放大器结构.....................................................................263.5折叠式共源共栅运放算放大器结构.................................................................333.6共模负反馈电路.................................................................................................363.6.1连续型共模负反馈电路..........................................................................363.6.2离散型共模负反馈电路..........................................................................39第4章运算放大器的仿真............................................................................................414.1电路设计的目标.................................................................................................414.1.1任务书指标......................................................................................................414.1.2选取的电路结构......................................................................................424.2具体的设计..........................................................................................................434.2.1确定偏置电压..................................................................................