Cooling Requirements - TDK-Lambda CPFE500 Application Note

6. COOLING REQUIREMENTS

CPFE500F is designed to mounted in any orientation except horizontal with baseplate uppermost.
The PSU requires a combination of conduction cooling for the baseplate and convection cooling for the PCB
mounted components.
The PSU maybe specified with or without factory fitted cover.
Convection cooling is best achieved with the PSU mounted in a vertical plane allowing convected air to flow
through the cover side or end ventilation slots and across the PCB mounted components.
If horizontal mounting is necessary, the PSU should be specified without cover wherever possible to achieve
best convection cooling and life expectancy for the PCB mounted components.
Where it is necessary to verify the PSU component temperatures in the end application, refer to Figure 14 for
internal component temperature limits.
Figure 14 – Internal Component Temperature Limits
Component Reference
C1, C2, C3, C4, C5
C7, C8, C10, C14, C15
R2, R9, R10
L1, L2, L6
C11, C12, C25, C26
C16, C17, C22, C23
Baseplate
Notes
*1 Temperature limits for electrolytic capacitors C11,C12,C25,C26,C16,C17,C22,C23 are calculated to provide a 3year life expectancy.
Temperatures above the limit specified can be used up to a a maximum of 105DegC with a corresponding reduction in life expectancy.
The capacitor life expectancy will be halved for every 10DegC above the limit specified.
CPFE500F Application Note
Component Function
EMC capacitor - Type X2
EMC capacitor - Type Y2
Surge Suppression Varistor
EMC filter chokes
Bulk storage capacitor
Output filtering capacitor
PSU baseplate
Document Number : 61066 iss 2
Temperature Limit
100DegC
100DegC
85DegC
130DegC
*1
67.5DegC
*1
81DegC
85DegC
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