T22

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Revision: 13-May-2020

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Document Number: 40187

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2.

AC Ripple Voltage: in operation, the peak voltage

across the capacitor (DC working voltage plus peak

ripple voltage) must not exceed the rated working

voltage of the capacitor. The DC component of the

applied voltage should be sufficiently large to prevent

polarity reversal in excess of 3 V at +85 °C or 2 V at

125 °C.

There will be a point at the lower frequency and

capacitance values when the peak AC voltage will be

the limiting factor on the ripple current - not its heating

effects.

3.

Ripple Current Multipliers: the Standard Ratings table

list the maximum permissible RMS ripple current at

40 kHz for each rating. These values are based on the

maximum power dissipation allowed at that frequency.

This ripple current, will cause heating, which adds to the

ambient

temperature.

The

higher

ambient

temperatures, voltage derating or current derating is

required (see “Ripple Current Multipliers” table). Also

shown are the multipliers for ripple currents at various

frequencies, caused by the frequency dependence of

the (ESR) equivalent series resistance. (see “Typical

ESR as a Function of Frequency” chart)











TYP. ESR AS A FUNCTION OF FREQUENCY

0

0.2

0.6

0.8

0.4

1.4

1.2

1.0

FREQUENCY (Hz)

10

100

1K

40K 100K

10K

1M

RIPPLE CURRENT MULTIPLIERS VS. FREQUENCY, TEMPERATURE AND APPLIES PEAK VOLTAGE

FREQUENCY

OF APPLIED

RIPPLE

CURRENT

120 Hz

800 Hz

1 kHz

10 kHz

40 kHz

100 kHz

AMBIENT STILL

AIR TEMP. IN °C

 55 85 105 125  55 85 105 125  55 85 105 125  55 85 105 125  55 85 105 125  55 85 105 125

% of

85 °C

rated

peak

voltage

100 %

0.60 0.39

-

-

0.71 0.43

-

-

0.72 0.46

-

-

0.88 0.55

-

-

1.0 0.63

-

-

1.1 0.69

-

-

90 %

0.60 0.46

-

-

0.71 0.55

-

-

0.72 0.55

-

-

0.88 0.67

-

-

1.0 0.77

-

-

1.1 0.85

-

-

80 %

0.60 0.52 0.35

-

0.71 0.62 0.42

-

0.72 0.62 0.42

-

0.88 0.76 0.52

-

1.0 0.87 0.59

-

1.1 0.96 0.65

-

70 %

0.60 0.58 0.44

-

0.71 0.69 0.52

-

0.72 0.70 0.52

-

0.88 0.85 0.64

-

1.0 0.97 0.73

-

1.1 1.07 0.80

-

66 2/3 % 0.60 0.60 0.46 0.27 0.71 0.71 0.55 0.32 0.72 0.72 0.55 0.32 0.88 0.88 0.68 0.40 1.0 1.0 0.77 0.45 1.1 1.1 0.85 0.50