Battery/Charger Load Switch Approximates Ideal Diode

Abstract:Twocircuitsaredescribed.ThefirstusesexternalMOSFETsdrivenbythePowerOK(POK)outputofaLi-cellchargerIC(MAX8814),toswitchaloadbetweenbatteryandchargingsourcewithoutinterventionfromamicrocontrollerorsystemsoftware.ForchargerICswithoutaPOKoutput(suchastheMAX1507),thesecondcircuitdoesthesameswitchingusingMOSFETsandacomparator(MAX920).Maxim>Designsupport>Appnotes>AmplifierandComparatorCircuits>APP4840Maxim>Designsupport>Appnotes>BatteryManagement>APP4840Keywords:loadswitching,rechargeablebattery-poweredsystems,Li+batterychargers,powerOK(POK)outputsFeb10,2011APPLICATIONNOTE4840Battery/ChargerLoadSwitchApproximatesIdealDiodeBy:BudgeIngHubertBugajskiAbstract:Twocircuitsaredescribed.ThefirstusesexternalMOSFETsdrivenbythePowerOK(POK)outputofaLi-cellchargerIC(MAX8814),toswitchaloadbetweenbatteryandchargingsourcewithoutinterventionfromamicrocontrollerorsystemsoftware.ForchargerICswithoutaPOKoutput(