GENERALDESCRIPTIONThePW4554isacost-effective,fullyintegratedhighinputvoltagesingle-cellLi-ionbatterycharger.ThechargerusesaCC/CVchargeprofilerequiredbyLi-ionbattery.Thechargeracceptsaninputvoltageupto24VbutisdisabledwhentheinputvoltageexceedstheOVPthreshold,typically6.8V,topreventexcessivepowerdissipation.The24Vratingeliminatestheover-voltageprotectioncircuitrequiredinalowinputvoltagecharger.ThechargecurrentandtheFull-of-charge(FOC)currentareprogrammablewithexternalresistors.Whenthebatteryvoltageislowerthan2.55V,thechargerpreconditi***thebatterywithtypically20%oftheprogrammedchargecurrent.WhenthechargecurrentreducestotheprogrammableFOCcurrentlevelduringtheCVchargephase,anFOCindicationisprovidedbytheCHGpin,whichisanopen-drainoutput.Aninternalthermalfoldbackfunctionprotectsthechargerfromanythermalfailure.Twoindicationpins(PPRandCHG)allowsimpleinterfacetoamicroprocessororLEDs.Whennoadapterattached,thechargerdrawslessthan1μAleakagecurrentfromthebattery.ThePW4554is***ailableinGreenDFN-2×2-8Lpackagesandisratedbetween-40℃to+85℃temperaturerange.FEATURESCompleteChargerforSingle-Cell-Li-ionorPolymerBatteriesIntegratedPassElementandCurrentSensorNoExternalBlockingDiodeRequiredLowComponentCountandCostProgrammableChargerCurrentProgrammableFull-of-ChargerCurrentChargerCurrentThermalFoldbackforThermalProtection)