Panasonic EE23 Circuit Design, Expected Life Estimate Quick Reference Guide, Failure rate curve

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Aluminum Electrolytic Capacitor

Application Guidelines

1. Circuit Design

E n s u r e t h a t operational and mounting conditions follw the specified conditions detailed in the catalog and specification sheets.

1.1 Operating Temperature and Frequency

Electrolytic capacitor electrical parameters are normally specified at 20°C temperature and 120Hz frequency. These parameters vary with changes in t e m p e ra t u r e a n d f r e q u e n c y. C i r c u i t d e s i g n e r s should take these changes into consideration.

(1)Effects of operating temperature on electrical parameters

a)At higher temperatures, leakage current and capacitance increase while equivalent series resistance(ESR) decreases.

b)At lower temperatures, leakage current and capacitance decrease while equivalent series resistance(ESR) increases.

(2) Effects of frequency on electr ical parameters a ) A t h i g h e r f r e q u e n c i e s , c a p a c i t a n c e a n d impedance decrease while tan δ increases.

b)At lower frequencies, ripple current generated heat will rise due to an increase in equivalent series 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

t h e l owe s t p o s s i b l e t e m p e r a t u r e b e l ow t h e maximum guaranteed temperature.

(2) If operating conditions exceed the maximum g u a r a n t e e d l i m i t , r a p i d e I e c t r i c a l p a ra m e t e r deterioration will occur, and irreversible damage will result.

Check for maximum capacitor operating tempera- tures including ambient temperature, internal capacitor temperature rise caused by ripple current, and the effects of radiated heat from power 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 formula for calculating expected Iife at lower operating temperatures is as fllows;

T1-T2

L2 = L1 x 2 10 where,

L1: Guaranteed life (h) at temperature, T1° C

L2: Expected life (h) at temperature,T2°C

T1: Maximum operating temperature (°C)

T2: Actual operating temperature, ambient temperature + temperature rise due to ripple currentheating(°C)

A quick eference capacitor guide for estimating exected life is included for your reference.

Expected Life Estimate Quick Reference Guide

Temperature

120

 

 

 

 

 

 

1. 85°C2000h

110

2

3

4

 

 

 

2.105°C1000h

 

 

 

 

°

 

 

 

 

 

 

 

3.105 C2000h

100

 

 

 

 

 

 

 

°

 

 

 

 

 

 

 

4.105 C5000h

90

 

1

 

 

 

 

 

 

Ambient

80

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

70

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Capacitor

60

 

 

 

 

 

 

 

 

50

 

 

 

 

 

 

 

 

40

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

24h

(h)

 

2000

5000

10,000

20,000

50,000

100,000

200,000

 

 

 

 

 

 

 

 

operat-

Years

1

2

3

4 5

7

20

ion

 

 

 

 

 

 

 

 

8h/d

Years

3

6

10

15

20

30

 

 

 

 

 

 

Failure rate curve

 

Initial failure period

 

 

Random failure period

Wear failure period

rate

Life Time

 

Failure

 

 

 

 

Time

 

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

Mar. 2005

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Contents Specification Dimensions in mm not to scaleSeries FA Type a Explanation of Part NumbersCase size / Impedance / Ripple current V.DC10C +20C V.DC 16 1C 25 1EV.DC 50 1H 10 C +20 CV.DC 63 1J EE25Operating Temperature and Frequency Operating Temperature and Life ExpectancyCircuit Design Expected Life Estimate Quick Reference GuideFaliure mode Typical failure modes and their factorsProduction factor Application factor EE17Using Two or More Capacitors in Series or Parallel Capacitor Mounting Considerations6Electrical Isolation of the Capacitor Capacitor Handling TechniquesEB Series Emergency Procedures Precautions for using capacitorsLong Term Storage Capacitor Disposal EE22