标签: ripple

FAIRCHILDCD404012-StageRippleCarryBinaryCounters.pdf

ConcurrentFrictionandRippleModelingforServomechanismsUsingaHystereticRelay(陈国强)

Abstract:ChargepumpsareaformofDC-DCconverterthatrelyoncapacitorsinsteadofinductorsforenergystorageandtransfer.Theabsenceofinductorsmakesthemattractiveinsituationsrequiringalow-powerauxiliarysupply(outputcurrentsuptoabout150mA).Theyuselesscircuit-boardarea,offerminimalcomponentheight,andareeasytouseMaxim>AppNotes>A/DandD/ACONVERSION/SAMPLINGCIRCUITSKeywords:SimpleMethodsReduceInputRippleforAllChargePumpsMay13,2003APPLICATIONNOTE2027SimpleMethodsReduceInputRippleforAllChargePumpsAbstract:ChargepumpsareaformofDC-DCconverterthatrelyoncapacitorsinsteadofinductorsforenergystorageandtransfer.Theabsenceofinductorsmakesthemattractiveinsituationsrequiringalow-powerauxiliarysupply(outputcurrentsuptoabout150mA).Theyuselesscircuit-boardarea,offerminimalcomponentheight,andareeasytouse.Chargepumpscanhaveregulatedorunregulatedoutputs.Anunregulatedchargepumpeitherdoublesorinvertsthevoltagethatpowersitandtheoutputvoltageisafunctionofthesupplyvol……

RippleandNoisemeasurementBTCPowerAN01RippleandNoiseMeasuringOutputNoiseandRippleMeasuringoutputnoiseandripplerequiresabasicunderstandingofthehighfrequencynatureofnoise.Veryoften,‘noise’(ascommonlymeasured)isactuallythevectorsumofcommonanddifferentialmodenoise.Commonmodenoiseiscommontobothoutputs(i.e+OUTand-OUT)withrespecttochassisorearthground.Differentialmodenoiseisfoundatoneoutputwithrespecttotheother.Whilethesystemloadcanbeaffectedbydifferentialmodenoise,itisseldomaffectedbycommonmodenoise.Thecommonmodenoiseisoftenonlycreatedintheprocessofmeasuringthedifferentialmodenoise.Noisecanbemeasuredasrootmeansquare(RMS)orpeaktopeak.Lowfrequencynoisewithalowpeaktoaverageratioisoftenm……

HOWTOTESTOUTPUTRIPPLEANDNOISEOFPOWERSUPPLIESAPPLICATIONNOTEHOWTOTESTOUTPUTRIPPLEANDNOISEOFPOWERSUPPLIESTheswitchingpowersupplies(eitherstep-downregulators,orisolatedDC-DCconverters,orOFFLINEpowersupplies)havethefundamentaladvantageofhighefficiencyi.e.lowpowerdissipationwhencomparedtolinearvoltageregulation.Howevertheswitchingtechnique,thatisbeneficialtoraisetheefficiency,hasanassociatedweaknessi.e.theoutputvoltagehasalwaysanACcontent.Thetypicaloutputrippleandnoiseofaswitchingpowersupplyisasshowninfig.1.Figure1.OutputrippleandnoiseofaswitchingpowersupplyFourACcomponentscanbeidentified:lowfrequencyrippleat2fbeingftheACmainsfrequencyhighfrequencyrippleduetoPulseWidthModulation(PWM)toobtaintherequiredlinean……