Aluminum Electrolytic Capacitor

Design, Specifications are subject to change without notice. Ask factory for technical specifications before purchase and/ or use.

Whenever a doubt about safety arises from this product, please inform us immediately for technical consulation without fail.

– EE16 –

Application Guidelines

1. Circuit Design

Ensure that operational and mounting conditions

follw the specified conditions detailed in the catalog

and specification sheets.

1.1 Operating Temperature and Frequency

Electrolytic capacitor electr ical par ameters are

nor mally specified at 20

°C temperature and 120Hz

frequency. These parameter s var y with changes in

temper ature and fr equency. Circuit designers

should take these changes into consideration.

(1) Effects of oper ating temper ature on electr ical

parameters

a)At higher temper atures, leakage current and

capacitance increase while equivalent series

resistance(ESR) decreases.

b)A t l o w er temperatures , leakage current and

capacitance decrease while equivalent series

resistance(ESR) increases.

(2) Effects of frequency on electr ical par ameters

a)At higher frequencies , capacitance and

impedance decrease while tan

δ increases.

b)At lower frequencies, r ipple current generated

heat will r ise due to an increase in equivalent

ser ies resistance (ESR).

1.2 Operating Temperature and Life Expectancy

(1) Expected life is affected by operating temperature.

Generally, each 10

°C reduction in temperature

will double the expected life. Use capacitors at

the lo w est possib le tem p e r ature belo w the

maximum guaranteed temperature.

(2) If oper ating conditions e xceed the maxim u m

guaranteed limit, rapid eIectr ical par ameter

deterioration will occur, and irreversible damage

will result.

Check for maximum capacitor operating tempera-

tures including ambient temperature, inter nal

capacitor temperature rise caused by ripple current,

and the eff ects of radiated heat from po wer

transistors, IC?s or resistors.

Avoid placing components which could conduct

heat to the capacitor from the back side of the circuit

board.

(3)The for mula for calculating expected Iife at lower

operating temperatures is as fllows;

where,

° C

°C

°C)

temperature + temperature rise due to

ripple currentheating(

°C)

A quick eference capacitor guide for estimating

exected life is included for your reference.

2000

5000

10,000

20,000

50,000 100,000 200,000

120

110

100

90

80

70

60

50

40

8h/d

1

2

3

4

5

7

20

3

6

10

15

20

30

s Expected Life Estimate Quick Reference Guide

s Failure rate curve

1. 85

°C2000h

2.105

°C1000h

3.105

°C2000h

4.105

°C5000h

1

2

3

4

(h)

Years

Years

24h

operat-

ion

Time

Initial failure period

Life Time

Random failure period

Wear failure period

10

Mar. 2005