Document Number: 40017

For technical questions, contact: aluminumcaps4@vishay.com

www.vishay.com

Revision: 28-Aug-08

8

550D

for High Frequency Power Supplies

Vishay Sprague

PERFORMANCE CHARACTERISTICS (Continued)

15.5

Following the thermal shock immersion cycling test,

capacitors shall meet the original requirements for

leakage current and dissipation factor; capacitance

change shall not exceed ± 5 % of the original

measured value.

15.6

Capacitors shall be opened and examined. There

shall be no evidence of dye penetration.

16.

Reduced Pressure Test:

16.1

Capacitors shall be stabilized at a reduced pressure

of 0.315" (8.0) of mercury, equivalent to an altitude of

100 000 feet (30.480 m), for a period of 5 min.

16.2

Rated DC voltage shall be applied for 1 min.

16.3

Capacitors shall not flash over nor shall end seals be

damaged.

16.4

Following the reduced pressure test, the capacitance,

equivalent series resistance and leakage current

shall meet the original requirements.

17.

Lead Pull Test: Leads shall withstand a tensile

stress of 3 pounds (1.4 kg) applied in any direction for

30 s.

18.

Marking: Capacitors shall be marked with Sprague

or (2); the type number 550D; rated capacitance and

tolerance, rated DC working voltage and the standard

EIA date code.

18.1

Capacitors shall be marked on one end with a plus

sign (+) to identify the positive terminal.

18.2

Vishay Sprague reserves the right to furnish

capacitors of higher working voltages than those

ordered, where the physical size of the higher voltage

units is identical to that of the units ordered.

GUIDE TO APPLICATION

1.

A-C Ripple Current: The maximum allowable ripple

current shall be determined from the formula:

where,

P =

Power Dissipation in W at + 25 °C as given in the

table in Paragraph Number 5

(Power Dissipation)

specified frequency

2.

A-C Ripple Voltage: The maximum allowable ripple

voltage shall be determined from the formula:

or, from the formula:

where,

P =

Power Dissipation in W at + 25 °C as given

in the table in Paragraph Number 5 (Power

Dissipation).

The

capacitor

Equivalent

Series

Resistance at the specified frequency.

Z =

The capacitor Impedance at the specified

frequency.

2.1

The sum of the peak AC voltage plus the DC voltage

shall not exceed the DC voltage rating of the

capacitor.

2.2

The sum of the negative peak AC voltage plus the

applied DC voltage shall not allow a voltage reversal

exceeding 15 % of the DC working voltage at + 25 °C.

3.

Reverse Voltage: These capacitors are capable of

withstanding peak voltages in the reverse direction

equal to 15 % of the DC rating at + 25 °C, 10 % of the

DC rating at + 55 °C; 5 % of the DC rating at + 85 °C.

4.

Temperature Derating: If these capacitors are to be

operated at temperatures above + 25 °C, the

permissible rms ripple current or voltage shall be

calculated using the derating factors as shown:

5.

Power Dissipation: The figures shown relate to an

approximate + 20 °C rise in case temperature

measured in free air. Power dissipation will be

affected by the heat sinking capability of the mounting

surface. Non-sinusoidal ripple current may produce

heating effects which differ from those shown. It is

important

that

the

equivalent

Irms

value

be

established when calculating permissable operating

levels.

I

rms

P

R

ESR

----------------

=

Temperature

Derating Factor

+ 25 °C

1.0

+ 55 °C

0.8

+ 85 °C

0.6

+ 125 °C

0.4

Case Code

Maximum Permissible

Power Dissipation at

+ 25 °C (W in free air)

R

0.185

S

0.225

V

rms

Z

P

R

ESR

----------------

=

V

rms

I

rms

Z

×

=