资源描述：
《第六章 运放放大器》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。
1、SENANJINGChapter6Chapter6OperationalAmplifierOperationalAmplifierwujinSECMFB:CMFB:全差分高阻输出特有问题全差分高阻输出特有问题NANJING低阻负载输出漏电压静态点有定义IDSPIIDSPIIDSNIDSNDSDS高阻负载输出漏电压静态无定义00CAVBVDSDSwujinSECMFB:CMFB:控制高阻漏端静态电压控制高阻漏端静态电压NANJING1.感应输出端共模电平CMFB本质为共模信2.利用该电平调节尾电流或负载电流号的负反馈放大器3.改变输出共模点wujinSECM
2、FB:CMCMFB:CM--DPDPNANJINGwujinSEFDFD--OPwithCMFBOPwithCMFBNANJINGwujinSEFDOPwithCBFBFDOPwithCBFBNANJINGwujinSEAmplifierAmplifierNANJING22--StageStageOperationalAmplifierOperationalAmplifierwujinSE22--StageOP:StageOP:NDP+CS+Output_BufferNDP+CS+Output_BufferNANJING内部结点共模电平由后级电路决定(V箝
3、位)GS前后级电平匹配输出共模点的定义:输出反馈输入定义wujinSE22--StageStage:PDP+CS+Output_BufferPDP+CS+Output_BufferNANJINGMode:ClassA,MatchingNeedfor2ndstagewujinSEMismatch:OffsetMismatch:OffsetVotageVotageofOPofOPNANJINGComefrom:MismatchofDP;SingleStageNoVConceptOSButSingleStageinDPhaveeffectonVofOPOSDef
4、inition:AppliedDifferentialSignalofVtosetstaticoutputosofOPthatatanypointchangingtotheneedCommonstateofV/2DDExample:UnitFBFollowerwithVinputatV+refV−VV/2−VCMrefDDrefV=理想分辨率V=实际分辨率id,realidAAVVV−V/2失调V=V−V=CMDD增益提高,输入失调降低OSid,realidAV高增益,V影响大,若V相对信号幅度小,则影响小OSOSwujinSEVVCalculation:
5、VCalculation:VMismatchMismatchOSTHNANJINGTowPart:ProcessRadomOffset:DeviceParametersMismatchun-controllable;Larger&DominantSystemicOffset:OperationpointMismatchControllable,Small&ignoredV−gΔVros,outmTH1,2oV===ΔVosTH1,2A−grVmoVMismatchTHVos,out−gm3ΔVTH3,4rogm3V===ΔVosTH3,4A−grgVm1o
6、m1gm3V=ΔV+ΔVos,VthTH1,2TH3,4gm1wujinSEVVCalculation:Calculation:W/LMismatch&TotalVMismatch&TotalVOSOS,RNANJING∂IDS1'2IDSΔIDS=k(V−V)==GSTH∂(W/L)2(W/L)Δ(W/L)IkΔ2/2Δ(V−V)Δ(W/L)Δ(W/L)DS===GSTHM=[]1,2+[]3,4GgkΔ22(W/L)(W/L)m1ΔIrΔIΔ(W/L)Δ(W/L)IDSoDSDSV==−=−×os,W/L−grΔ(W/L)g(W/L)gm1om1m1(
7、V−V)Δ(W/L)GSTH=−×2(W/L)gm3(VGS−VTH)1,2∂VOS,R=−1MVOS,R=ΔVTH1,2+ΔVTH3,4−MGGgm12∂VGS2V中每一项取绝对值,并可正可负,范围内随机变换OS,RwujinSEVVCalculation:Systematic&TotalCalculation:Systematic&TotalOSNANJING∂IDS1V1:outputofOPatPMOSDraingds==λ⋅IDS=ΔIDS=λ⋅IDSΔVds∂VdsrdsVy:PMOSCSDrainISSΔI−ΔI=Iλ[V−V−(V−V)]=
8、λ(V−V)D3D4DS3DDyDD131y2Matchingof
