specified as an effective (RMS) value at 100 or 120 Hz or at 10 kHz at upper category temperature. Non-sinusoidal ripple currents have to be analyzed and separated into their component sinusoidal frequencies by means of Fourier analysis and the equivalent ripple current calculated as the square root of the sum of the squares of the individual currents. In solid tantalum electrolytic capacitors the heat generated by the ripple current influences the reliability of the capacitors. Exceeding the limit tends to result in catastrophic failures with shorts and burning components. Current surge, peak or pulse current Solid tantalum electrolytic capacitors can be damaged by surge, peak or pulse currents. Tantalum capacitors, which are exposed to surge, peak or pulse currents should be used with a voltage derating up to 70% in highly inductive circuits. If possible, the voltage profile should be a ramp turn-on, as this reduces the peak current seen by the capacitor. Leakage current The DC leakage current is a special characteristic for electrolytic capacitors other conventional capacitors don't have. This current is represented by the resistor Rleak in parallel with the capacitor in the series-equivalent circuit of electrolytic capacitors. The main causes of leakage current for solid tantalum capacitors are electrical breakdown of the dielectric, conductive paths due to impurities or due to poor anodization, bypassing of dielectric due to excess manganese dioxide, due to moisture paths or due to cathode conductors (carbon, silver). This leakage current in solid electrolyte capacitors cannot be reduced by "healing" in the sense of generating new oxide because under normal conditions solid electrolytes are unable to deliver oxygen for forming processes. This statement should not be confused with the self-healing process during field crystallization, as described in Reliability (failure rate). The specification of the leakage current in datasheets often will be given by multiplication of the rated capacitance value CR with the value of the rated voltage UR together with an addendum figure, measured after a measuring time of 2 or 5 minutes, for example: The value of the leakage current depends on the voltage applied, on temperature of the capacitor, on measuring time, and on influence of moisture caused by case sealing conditions. They normally have a very low leakage current, most much lower than the specified worst-case. Dielectric absorption (soakage) Dielectric absorption occurs when a capacitor that has remained charged for a long time retains some charge when briefly