beautypg.com

Scl series ● reliability of tantalum capacitors – Samsung SCLSeries User Manual

Page 19

background image

SCL Series

RELIABILITY OF TANTALUM CAPACITORS

General

The failure rate of the tantalum capacitor varies with the digression ratio, ambient temperature, circuit

resistance, circuit application, etc.

Therefore, when proper selections are made so as to afford additional margins, higher reliability can

be derived from the tantalum capacitors. Some examples of actual failure rates are presented below

for your reference.

Failure Rate Calculation Formula

The tantalum capacitors are designed to work at their basic failure

rates shown in Table 3 that prevail when the rated voltage is applied for 1000 hours at 85℃.

Table 3 Basic failure rate

Failure rate calculation formula

λ

use = λ85 x K

V

x K

R

λ

use : Estimated capacitor failure rate under the operating conditions.

λ

85 : Basic failure rate (Table 3)

K

V : Failure rate correction coefficient by the ambient temperature and derating factor.

K

R : Failure rate correction coefficient by the circuit resistance,

which is the series-connected resistance divided by the voltage applied to the capacitor.

This resistance is connected in series when the power supply side is viewed from the capacitor side.

K

(derating factor)=operating voltage/rated voltage

TYPE

Classification

Basic failure rate

S C E ,SV E

Low E S R type

1% /10 00h

S C M ,S V M

U ltra-M in iaturization Type(060 3)

S C L

Low -p ro file Type

S C S ,SV S

S m all Type

S C N ,S V N

S tanda rd type

P C *

C ondu ctive P olym er Type