Document Number: 40052

Revision 04-Feb-03

www.vishay.com

4

Type 255D

Vishay Sprague

PERFORMANCE CHARACTERISTICS

1.

Operating Temperature: Capacitors are designed to

operate over the temperature range of - 55

°C to

+105

°C.

1.1 Capacitors may be operated to + 105

°C with voltage

derating to 0.8 times the + 85

°C rating.

- 55

°C

+ 85

°C

+ 105

°C

5.

Capacitance Change With Temperature:

The

capacitance change with temperature shall not exceed

the following percentage of the capacitance measured

at + 25

°C: at

6.

Dissipation Factor: The dissipation factor, determined

from the expression 2

πfRC, shall not exceed values listed

in the Standard Ratings Table.

6.1 Measurements shall be made by the bridge method at,

or referred to, a frequency of 120Hz and a temperature

of + 25

°C.

7.

Leakage Current: Capacitors shall be stabilized at the

rated temperature for 30 minutes. Rated voltage shall

be applied to capacitors for 5 minutes using a steady

source of power (such as a regulated power supply) with

1000 ohm resistor connected in series with the capaci-

tor under test to limit the charging current. Leakage cur-

rent shall then be measured.

7.1 At + 25

listed in the Standard Ratings Table.

7.2 At + 85

the value listed in the Standard Ratings Table.

7.3 At + 105

times the rated voltage, shall not exceed 10 times the

value listed in the Standard Ratings Table.

8.

ESR

8.1 ESR (Equivalent Series Resistance) shall not exceed

the values listed in the Ratings Table. Measurement shall

be made by the bridge method at a frequency of 100kHz

and a temperature of + 25

°C.

9.

Life Test: Capacitors shall withstand rated DC voltage

applied at + 85

°C for 1000 hours.

9.1 Following the life test, the dissipation factor shall not

exceed 1.5 times the initial requirement; the capacitance

change shall not exceed

±20%; the leakage current shall

not exceed 0.1 CV (3uA).

2.

DC Working Voltage: The DC working voltage is the

maximum operating voltage for continuous duty at the

rated temperature.

3.

Surge Voltage: The surge DC rating is the maximum

voltage to which the capacitors may be subjected un-

der any conditions, including transients and peak ripple

at the highest line voltage.

3.1 Surge Voltage Test: Capacitors shall withstand the

surge voltage applied in series with a 33 ohm

± 5%

resistor at the rate of one-half minute on, one-half minute

off, at + 85

°C, for 1000 successive test cycles.

3.2 Following the surge voltage test, the dissipation factor

shall meet the initial requirements; the capacitance shall

not have changed more than

± 20%. The leakage cur-

rent shall not exceed 150% of the initial value.

4.

Capacitance Tolerance: The capacitance of all capaci-

tors shall be within the specified tolerance limits of the

normal rating.

4.1 Capacitance measurements shall be made by means

of polarized capacitance bridge. The polarizing voltage

shall be of such magnitude that there shall be no rever

sal of polarity due to the AC component. The maximum

voltage applied to capacitors during measurement shall

be 2 volts rms at 120Hz at + 25

°C. If the AC voltage

applied is less than one-half volt rms, no DC bias is re-

quired. Accuracy of the bridge shall be within

± 2%.

+ 85

+ 105

WORKING

SURGE

WORKING

SURGE

VOLTAGE

VOLTAGE

VOLTAGE

VOLTAGE

(V)

(V)

(V)

(V)

4.0

5.2

3.2

4.3

6.3

8.0

5.0

6.5

10.0

13.0

8.0

10.4