资源描述:
《5 analog filters》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、ANALOGFILTERSHOpAmpHistory1OpAmpBasics2SpecialtyAmplifiers3UsingOpAmpswithDataConverters◆4SensorSignalConditioning◆5AnalogFilters1Introduction2TheTransferFunction3TimeDomainResponse4StandardResponses5FrequencyTransformations6FilterRealizations7PracticalProblemsinFilterImplement
2、ation8DesignExamples6SignalAmplifiers7HardwareandHousekeepingTechniquesOPAMPAPPLICATIONSANALOGFILTERSINTRODUCTIONCHAPTER5:ANALOGFILTERSHankZumbahlenSECTION5-1:INTRODUCTIONFiltersarenetworksthatprocesssignalsinafrequency-dependentmanner.Thebasicconceptofafiltercanbeexplainedbyex
3、aminingthefrequencydependentnatureoftheimpedanceofcapacitorsandinductors.Consideravoltagedividerwheretheshuntlegisareactiveimpedance.Asthefrequencyischanged,thevalueofthereactiveimpedancechanges,andthevoltagedividerratiochanges.Thismechanismyieldsthefrequencydependentchangeinth
4、einput/outputtransferfunctionthatisdefinedasthefrequencyresponse.Filtershavemanypracticalapplications.Asimple,singlepole,lowpassfilter(theintegrator)isoftenusedtostabilizeamplifiersbyrollingoffthegainathigherfrequencieswhereexcessivephaseshiftmaycauseoscillations.Asimple,single
5、pole,highpassfiltercanbeusedtoblockDCoffsetinhighgainamplifiersorsinglesupplycircuits.Filterscanbeusedtoseparatesignals,passingthoseofinterest,andattenuatingtheunwantedfrequencies.Anexampleofthisisaradioreceiver,wherethesignalyouwishtoprocessispassedthrough,typicallywithgain,wh
6、ileattenuatingtherestofthesignals.Indataconversion,filtersarealsousedtoeliminatetheeffectsofaliasesinA/Dsystems.TheyareusedinreconstructionofthesignalattheoutputofaD/Aaswell,eliminatingthehigherfrequencycomponents,suchasthesamplingfrequencyanditsharmonics,thussmoothingthewavefo
7、rm.Therearealargenumberoftextsdedicatedtofiltertheory.Noattemptwillbemadetogoheavilyintomuchoftheunderlyingmath:Laplacetransforms,complexconjugatepolesandthelike,althoughtheywillbementioned.Whiletheyareappropriatefordescribingtheeffectsoffiltersandexaminingstability,inmostcases
8、examinationofthefunctioninthefrequencydomainismoreillu