MAY 2013

TAP/TEP Technical Summary and

Application Guidelines

1.4.4 Temperature dependence of the impedance and ESR

At 100 kHz, impedance and ESR behave identically and

decrease with increasing temperature as the typical curves

show. For maximum limits at high and low temperatures,

please refer to graph opposite.

1.5 DC LEAKAGE CURRENT (DCL)

1.5.1 Leakage current (DCL)

The leakage current is dependent on the voltage applied, the

time, and the capacitor temperature. It is measured

at +25°C with the rated voltage applied. A protective resist-

ance of 1000

is connected in series with the capacitor

in the measuring circuit.

Three minutes after application of the rated voltage the leak-

age current must not exceed the maximum values indicated

in the ratings table. Reforming is unnecessary even after pro-

longed periods without the application of voltage.

1.5.2 Temperature dependence of the leakage current

The leakage current increases with higher temperatures, typical

values are shown in the graph.

For operation between 85°C and 125°C, the maximum

working voltage must be derated and can be found from the

following formula.

V max = 1- (T-85)

120

where T is the required operating temperature. Maximum

limits are given in rating tables.

1.5.3 Voltage dependence of the leakage current

The leakage current drops rapidly below the value corre-

applied. The effect of voltage derating on the leakage

current is shown in the graph.

This will also give a significant increase in reliability for any

application. See Section 3 (pages 155-157) for details.

1.5.4 Ripple current

The maximum ripple current allowance can be calculated from

the power dissipation limits for a given temperature rise above

ambient. Please refer to Section 2 (page 154) for details.

10

1

0.1

-55 -40 -20

0

20

40

60

80 100 125

Temperature

°C

Temperature Dependence of the

Leakage Current for a Typical Component

Effect of Voltage Derating on Leakage Current

1

0.1

0.01

020

40

60

80

100

TYPICAL

RANGE

1/35

10/35

47/35

100

10

1

0.1

-55

-40

-20

0

+20

+40

+60

+80 +100 +125

Temperature T (C)

Temperature Dependence of the

Impedance and ESR