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## SR215C104GAT Datasheet(HTML) 5 Page - AVX Corporation

 5 / 72 page3In practice the current leads the voltage by some otherphase angle due to the series resistance RS. The comple-ment of this angle is called the loss angle and:Power Factor (P.F.) = Cos f or SineDissipation Factor (D.F.) = tanfor small values ofthe tan and sine are essentially equalwhich has led to the common interchangeability of the twoterms in the industry.Equivalent Series Resistance – The term E.S.R. orEquivalent Series Resistance combines all losses bothseries and parallel in a capacitor at a given frequency sothat the equivalent circuit is reduced to a simple R-C seriesconnection.Dissipation FactorThe DF/PF of a capacitor tells what percent of theapparent power input will turn to heat in the capacitor.Dissipation Factor =E.S.R.= (2π fC) (E.S.R.)XCThe watts loss are:Watts loss = (2π fCV2) (D.F.)Very low values of dissipation factor are expressed as theirreciprocal for convenience. These are called the “Q” orQuality factor of capacitors.Insulation Resistance – Insulation Resistance is the resis-tance measured across the terminals of a capacitor andconsists principally of the parallel resistance RP shown inthe equivalent circuit. As capacitance values and hence thearea of dielectric increases, the I.R. decreases and hencethe product (C x IR or RC) is often specified in ohm faradsor more commonly megohm microfarads. Leakage currentis determined by dividing the rated voltage by IR (Ohm’sLaw).Dielectric Strength – Dielectric Strength is an expressionof the ability of a material to withstand an electrical stress.Although dielectric strength is ordinarily expressed in volts,it is actually dependent on the thickness of the dielectricand thus is also more generically a function of volts/mil.Dielectric Absorption – A capacitor does not dischargeinstantaneously upon application of a short circuit, butdrains gradually after the capacitance proper has been dis-charged. It is common practice to measure the dielectricabsorption by determining the “reappearing voltage” whichappears across a capacitor at some point in time after ithas been fully discharged under short circuit conditions.Corona – Corona is the ionization of air or other vaporswhich causes them to conduct current. It is especiallyprevalent in high voltage units but can occur with lowvoltages as well where high voltage gradients occur. Theenergy discharged degrades the performance of thecapacitor and can in time cause catastrophic failures.CERAMIC CAPACITORSMultilayer ceramic capacitors are manufactured by mixingthe ceramic powder in an organic binder (slurry) and cast-ing it by one technique or another into thin layers typicallyranging from about 3 mils in thickness down to 1 mil orthinner.Metal electrodes are deposited onto the green ceramiclayers which are then stacked to form a laminatedstructure. The metal electrodes are arranged so that theirterminations alternate from one edge of the capacitor toanother. Upon sintering at high temperature the partbecomes a monolithic block which can provide extremelyhigh capacitance values in small mechanical volumes.Figure 1 shows a pictorial view of a multilayer ceramiccapacitor.Multilayer ceramic capacitors are available in a wide range ofcharacteristics, Electronic Industries Association (EIA) andthe military have established categories to help divide theThe CapacitorE.S.R.CI (Ideal)I (Actual)PhaseAngleLossAngleVIRsf