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1、[键入文字]需要购买毕业论文/毕业设计，请登陆360毕业设计网---www.bysj360.com或加QQ：604664738AnalogandDigitalIdealOperationalAmplifiersandPracticalLimitationsInordertodiscusstheidealparametersofoperationalamplifiers,wemustfirstdefinetheterms,andthengoontodescribewhatweregardastheidealvaluesforthoseterms.Atfir
2、stsight,thespecificationsheetforanoperationalamplifierseemstolistalargenumberofvalues,someinstrangeunits,someinterrelated,andoftenconfusingtothoseunfamiliarwiththesubject.Theapproachtosuchasituationistobemethodical,andtakethenecessarytimetoreadandunderstandeachdefinitionintheorde
3、rthatitislisted.Withoutarealappreciationofwhateachmeans,thedesignerisdoomedtofailure.Theobjectiveistobeabletodesignacircuitfromthebasisofthepublisheddata,andknowthatitwillfunctionaspredictedwhentheprototypeisconstructed.1Itisalltooeasywithlinearcircuits,whichappearrelativelysimpl
4、ewhencomparedwithtoday’scomplexlogicarrangements,toignoredetailedperformanceparameterswhichcandrasticallyreducetheexpectedperformance.Letustakeaverysimplebutstrikingexample.Considerarequirementforanamplifierhavingavoltagegainof10at50 KHzdrivingintoa10kWload.Acommonlow-cost,intern
5、allyfrequency-compensatedopampischosen;ithastherequiredbandwidthataclosed-loopgainof10,anditwouldseemtomeetthebill.Thedeviceisconnected,anditisfoundtohavethecorrectgain.Butitwillonlyproduceafewvoltsoutputswingwhenthedataclearlyshowsthattheoutputshouldbecapableofdrivingtowithintwo
6、orthreevoltsofthesupplyrails.Thedesignerhasforgottenthatthemaximumoutputvoltageswingisseverelylimitedbyfrequency,andthatthemaximumlow-frequencyoutputswingbecomeslimitedatabout10 KHz.Ofcourse,theinformationisinfactonthedatasheet,butitsrelevancehasnotbeenappreciated.Thissortofprobl
7、emoccursregularlyfortheinexperienceddesigner.Sothemoralisclear:alwaystakethenecessarytimetowritedownthefulloperatingrequirementsbeforeattemptingadesign.Attentiontothedetailoftheperformancespecificationwillalwaysbebeneficial.Itissuggestedthefollowinglistofperformancedetailsbeconsi
8、dered:1.Closedloopgainaccuracy,stability
