Understanding Op Amp Parameters

《Understanding Op Amp Parameters》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。

1、Chapter11UnderstandingOpAmpParametersLiteratureNumberSLOA083ExcerptedfromOpAmpsforEveryoneLiteratureNumber:SLOD006AChapter11UnderstandingOpAmpParametersBruceCarter11.1IntroductionThischapterisaboutopampdatasheetparameters.Thedesignermusthaveaclearun-derstandingofwhatopampparametersmeanandtheiri

2、mpactoncircuitdesign.Thechapterisarrangedforspeedyaccesstoparameterinformation.Theirdefinitions,typicalabbreviations,andunitsappearinSection11.2.Section11.3digsdeeperintoimportantparametersforthedesignerneedingmorein-depthinformation.WhiletheseparametersaretheonesmostcommonlyusedatTexasInstrume

3、nts,thesameparametermaygobydifferentnamesandabbreviationsatothermanufacturers.Noteveryparameterlistedheremayappearinthedatasheetforagivenopamp.Anopampthatisintendedonlyforacapplicationsmayomitdcoffsetinformation.Theomissionofinformationisnotanattemptto“hide”anything.Itismerelyanattempttohighlig

4、httheparametersofmostinteresttothedesignerwhoisusingthepartthewayitwasintended.Thereisnosuchthingasanidealopamp—oronethatisuniversallyapplicable.Theselectionofanyopampmustbebasedonanunderstandingofwhatparticularparame-tersaremostimportanttotheapplication.Ifaparticularparametercannotbefoundinthe

5、datasheet,areviewoftheapplicationmaywellbeinorderandanotherpart,whosedatasheetcontainsthepertinentinformation,mightbemoresuitable.TexasInstrumentsmanufacturesabroadlineofopampsthatcanimplementalmostanyapplication.Theinexperienceddesignercouldeasilyselectanopampthatistotallywrongfortheapplicatio

6、n.Tryingtouseanaudioopampwithlowtotalharmonicdistortioninahigh-speedvideocircuit,forexample,willnotwork—nomatterhowsuperlativetheaudioperformancemightbe.Someparametershaveastatisticallynormaldistribution.Thetypicalvaluepublishedinthedatasheetisthemeanoraveragevalueofthedistribution.Thetypicalva

7、luelistedisthe1svalue.Thismeansthatin68%ofthedevicestested,theparameterisfoundtobe±thetypicalvalueorbetter.TexasInstrumentscurrentlyuses6stodefineminimumandmaximumvalues.Usually,typicalvaluesaresetwhenthepartischaracterizedandneve