Polymer Guide

www.vishay.com

Vishay

Revision: 08-Sep-2022

11

Document Number: 40076

For technical questions, contact: polytech@vishay.com

THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT

ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000

HERMETICALLY SEALED CAPACITOR T27 TYPE

GUIDE TO APPLICATION

1.

AC Ripple Current: the maximum allowable ripple

current shall be determined from the formula:

where,

P =

power dissipation in W at +45 °C as given in

the tables in the product datasheets.

RESR = the capacitor equivalent series resistance at

the specified frequency.

2.

AC Ripple Voltage: the maximum allowable ripple

voltage shall be determined from the formula:

or, from the formula:

where,

P =

power dissipation in W at +45 °C as given in

the tables in the product datasheets.

RESR = The capacitor equivalent series resistance at

the specified frequency.

Z =

The capacitor impedance at the specified

frequency.

2.1

The tantalum capacitors must be used in such a

condition that the sum of the working voltage and

ripple voltage peak values does not exceed the rated

voltage as shown in figure below.

3.

Temperature

Derating:

power

dissipation

is

affected by the heat sinking capability of the

mounting surface. If

these

capacitors

are

to

be operated at temperatures above +45 °C, the

permissible ripple current (or voltage) shall be

calculated using the derating coefficient as shown in

the table below:

4.

Reverse Voltage: the capacitors are not intended for

use with reverse voltage applied. However, they are

capable of withstanding momentary reverse voltage

peaks, which must not exceed the following values:

At 25 °C: 10 % of the rated voltage or 1 V, whichever

is smaller.

At 85 °C: 5 % of the rated voltage or 0.5 V, whichever

is smaller.

At 105 °C: 3 % of the rated voltage or 0.3 V,

whichever is smaller.

5.

Mounting Precautions:

5.1

Soldering:

capacitors

can

be

attached

by

conventional soldering techniques; vapor phase,

convection reflow, infrared reflow, wave soldering,

and hot plate methods. The soldering profile charts

show recommended time / temperature conditions

for soldering. Preheating is recommended. The

recommended maximum ramp rate is 3 °C per

second. Attachment with a soldering iron is not

recommended due to the difficulty of controlling

temperature and time at temperature. The soldering

iron must never come in contact with the capacitor.

For details see www.vishay.com/doc?40214.

PAD DIMENSIONS in inches [millimeters]

CASE CODE

A (MIN.)

B (NOM.)

C (NOM.)

D (NOM.)

D

0.295 [7.50]

0.138 [3.50]

0.100 [2.50]

0.374 [9.50]

D

C

A

B

I

RM S

P

R

ESR

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

=

V

RM S

Z

P

R

ESR

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

=

V

RMS

I

RM S

x

Z

=

Rated voltage

Ripple voltage

Operating

voltage

Working voltage

Time (s)

MAXIMUM RIPPLE CURRENT TEMPERATURE

DERATING FACTOR

≤ 45 °C

1.0

55 °C

0.8

85 °C

0.6

105 °C

0.4

125 °C

0.25