Simple Methods Reduce Input Ripple for All Charge Pumps

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