APPLICATION NOTE应用笔记

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1、APPLICATIONNOTEAN2015Rev.0.00CurrentProtectionandMeasurementMay1,2009IntroductionThisapplicationnotedescribesthecurrent-sensingapparatusincorporatedintheZL2005powermanagementandconversionIC.ThevariousmodesofVINusingthehardware,appropriatesettingsandlimitationsA)ofthesemod

2、esareexplained.ISENAVOUTOverviewISENBSYNCHRONOUSMOSFETTheZL2005deliversworld-classpowerconversionRDS/ONSENSINGalongwithflexiblepowermanagementfunctionstopoint-of-load(PoL)regulatorapplications.TheZL2005containsamixed-signalcontrollerforaVINsynchronousbuckpowerconverteralo

3、ngwithB)functionalblocksformonitoringandreportingoutputVOUTvoltageandcurrent,inputvoltage,andbothinternalISENAandexternaltemperatures.CoordinationamongmultipleZL2005controllersandapowersystemhostLSRESISTANCEISENBSENSINGisprovidedbycommunicationsonanintegratedPMBusserialp

4、ort.Theresultingpowersystemarchitectureissimpletomanage,yetflexibleinallaspectsofpowersystemperformance.VINC)CircuitConnectionsVOUTThecurrent-protectionfunctionoftheZL2005protectsthepowersupplyfromdamageiftheoutputisshortedtoground(GND)oranotherpowerrailorifanISENAHSINDUC

5、TORoverloadconditionisimposedontheoutput.TheISENBSENSINGZL2005isdesignedtobeusedinallcommoncurrent-sensingconfigurationsforsynchronousbuckconvertersusingN-channelMOSFETs.Figure1showsVINfourofthecommonconnections:A.SynchronousMOSFETRDS(ON)sensingD)RVOUTB.Groundreferencedre

6、sistancesensing(LSsensing)C.InlinesensingoftheinductorDCresistance(DCR)(HSinductorsensing)ISENAHSRESISTORD.Inline(HS)resistorsensingISENBSENSINGFigure1.Current-SensingMethodsAN2015Rev.0.00Page1of12May1,2009CurrentProtectionandMeasurementInadditiontotheseconnections,aconve

7、ntionalcurrentGeneralCurrent-SensingApproachsensetransformer,terminatedwithanappropriateTheZL2005usesamixed-signalimplementationtoburdenresistorandresetcircuit,canbesubstitutedforsensethecurrentsignalpresentedtotheISENAandeitheroftheLSsensingmethods.ISENBterminals,digitiz

8、eit,andperformthereportingTheimplementationofthecurrentsensingapparatusinandprotectionfunctionso