CN3300应用电路设计步骤

TerminationVoltage,BAT11.9InputVoltage,VCC8BatteryCapacity2200TargetChargeTime42.Forexample,iftwolithiunbatteriesarechargedbya5Vsupply,putVCC=5VandBAT=8.5V.(Asthereisresistancefrombatteriesandallinterconnections,BATshouldbehigherthan4.2Vx2=8.4V.)1.Pleaserefertodatasheetforotherparametersthathavenotbeencovered.CircuitDesignProceduresforCN3300PleaseEnterDesignSpecifications:Step1:ConstantChargeCurrentV(PleaseconsiderRinbattery)VmAHStep2:EstimateInductorCurrentHourStep3:CalculateRCSRCS0.1403Step4:CalculateLStep5:DesignFBResistorLadderR2200R11775.1C3291.1485122.Forexample,iftwolithiunbatteriesarechargedbya5Vsupply,putVCC=5VandBAT=8.5V.(Asthereisresistancefrombatteriesandallinterconnections,BATshouldbehigherthan4.2Vx2=8.4V.)L1.Pleaserefertodatasheetforotherparametersthathavenotbeencovered.0.9625Ich43.25IL0.55Step6:CalculateC3CircuitDesignProceduresforCN3300PleaseEnterDesignSpecifications:Step1:ConstantChargeCurrentRemarkStep2:EstimateInductorCurrentRemarkRemarkOhmRemarkStep5:DesignFBResistorLadderRemarkkOhmkOhmRemarkpFAssumetheswitchingfreq.is300kHz.uHAAStep6:CalculateC3Ratioisimportant.Othervaluescanbeselected.Astheswitchingfreq.is300kHz,theactualinductancewouldbelarger.CircuitDesignProceduresforCN3300Assumeascalingfactorof85%