Datasheet

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Surface Mount Aluminum Electrolytic Capacitors – EDK, +85°C
Application and Operation Guidelines
Electrical Ratings:
Capacitance (ESC)
Simplifi ed equivalent circuit diagram of an electrolytic capacitor
Thecapacitivecomponentoftheequivalentseriescircuit,(equivalentseriescapacitance-ESC),isdeterminedbyapplying
analternatevoltageof≤0.5Vatafrequencyof120or100Hzand20°C(IEC384-1,384-4).
Temperature Dependence of the Capacitance
Capacitanceofanelectrolyticcapacitordependsupontemperature:withdecreasingtemperaturetheviscosityofthe
electrolyteincreases,therebyreducingitsconductivity.
Capacitancewilldecreaseiftemperaturedecreases.Furthermore,temperaturedriftscausearmaturedilatationand,
therefore,capacitancechanges(upto20%dependingontheseriesconsidered,from0to80°C).Thisphenomenonismore
evidentforelectrolyticcapacitorsthanforothertypes.
Frequency Dependence of the Capacitance
Effectivecapacitancevalueisderivedfromtheimpedancecurve,aslongasimpedanceisstillintherangewherethe
capacitance component is dominant.
C =
1
C = capacitance (F)
2πfZ
f=frequency(Hz)
Z=impedance(Ω)
Dissipation Factor tan δ (DF)
DissipationFactortanδistheratiobetweentheactiveandreactivepowerforasinusoidalwaveformvoltage.Itcanbe
thoughtofasameasurementofthegapbetweenanactualandidealcapacitor.
reactive
active
ideal
actual
δ
Tanδismeasuredwiththesameset-upusedfortheseriescapacitanceESC.
Tanδ=ωxESCxESRwhere:
ESC = Equivalent series capacitance
ESR = Equivalent series resistance