电解电容纹波及寿命测试方法

ElectrolyticCapacitorRippleCurrentDeratingTestMethodandLifeTimeEvaluationFrom：郭雪松Date：Oct-27-04一．SPEC1.电解电容零件工程规格书中之StandardRating表格，其中规定了不同规格的电解电容RatedRippleCurrent值，例如：Sharp机种PWPCC904(滤波电容)67L215L-820-15N(CNN公司KXGSeries)VDCVCap.uFCasesize∮D*LmmtanδL.C.uARatedRippleCurrentmArms/105℃1min5min120Hz100KHz4508218*35.50.24157676371517852.此电容用于电源输入端滤波，因此采用120Hz时的RatedRippleCurrent规格715mA。3.而用于评估电解电容RippleCurrent之Spec要依据以下公式：SPEC=Spec（component）×频率系数（FM）×温度系数（TM）注：FM/TM取值方法见附表4.OTPV评估电解电容RippleCurrent的Derating规格为85％，因此测试值SPEC×85％时判定OK。二．TestMethod将电解电容接地端吸开串联一导线，直接用电流计探头测试该导线电流的有效值（rms），测试时要调整输入电压值（90V～264V）达到纹波电流最大。见图示：Irms三．附表（FM&TM取值方法）：NCC公司产品为例1.MultiplyingFactorsonKMGSeries（radialleadtype）FrequencyMultipliersRange50Hz120Hz300Hz1KHz10KHz100KHz～3.3uF0.651.001.351.752.302.504.7uF～33uF0.751.001.251.501.751.8047uF～1000uF0.801.001.151.301.401.502200uF～0.851.001.031.051.081.08TemperatureMultipliersTemp（℃）55657585105Multipliers2.232.2321.7312.MultiplyingFactorsonKYSeriesFrequencyMultipliersRange120Hz1KHz10KHz100KHz～180uF0.400.750.901.00220uF～560uF0.500.850.941.00680uF～1800uF0.600.870.951.002200uF～0.750.900.951.003900uF4700uF～0.850.950.981.00TemperatureMultipliersTemp（℃）55657585105Multipliers2.232.2321.7313.MultiplyingFactorsonKXGSeriesFrequencyMultipliersRange120Hz1KHz10KHz100KHz～100uF1.001.752.252.5120uF～1.001.671.752.25TemperatureMultipliersTemp（℃）55657585105Multipliers2.232.2321.731*Temperaturemultipliersshowstheguidelimitsofthemaximumavailableripplecurrentateachofthetemperature,ofwhichthelifetimeattheratedmaximumoperatingtemperatureisexpected.四．电解电容寿命评估测试方法1.CalculationFormula:电容寿命LifeTime=Life(spec)×2(Ts-Tt)/10Life(spec)：指spec中标明的寿命值Ts：电容最高使用温度值Tt：电容本体温度测试值2.判定方法：以上计算得出之寿命值与整机MTBF目标值比较，若大于目标值则判定OK。3.例如：SHARP机种C904Life（spec）＝10000Hrs，Ts＝105℃，Tt＝52.6℃，。SHARPMTBF目标50000Hrs。LifeTime＝10000×2(105-52.6)/10=377917Hrs50000HrsOK