Powersolve PS150 Series - Manual (Page 3)

Powersolve Electronics Ltd. Units 8A, Arnhem Road, Newbury, RG14 5RU. England
Tel:01635 521858 Fax: 01635 523771 Email: [email protected]
www.powersolve.co.uk
3
Derating:
The operating case temperature range of the PS150 series is -40°C to +100°C. When operating the PS150 series,
proper derating or cooling is needed.
The following curve is the derating curve of a PS150 without heat sink.
Where:
The power dissipation (Pd):
Pd = Pi - Po = Po (1-n) /n
The thermal resistance are listed below:
Chart of Thermal Resistance vs Air Flow:
The temperature rise ( T ):
T = Pd * Rca
Application Note
AIR FLOW RATE TYPICAL Rca
Natural Convection 20ft./min. (0.1m/s) 7.12 °C/W
100 ft./min. (0.5m/s) 6.21 °C/W
200 ft./min. (1.0m/s) 5.17 °C/W
300 ft./min. (1.5m/s) 4.29 °C/W
400 ft./min. (2.0m/s) 3.64 °C/W
500 ft./min. (2.5m/s) 2.96 °C/W
600 ft./min. (3.0m/s) 2.53 °C/W
700 ft./min. (3.5m/s) 2.37 °C/W
800 ft./min. (4.0m/s) 2.19 °C/W
Power Dissipated vs Ambient Temperature and Air Flow
15
10
5
0
Ambient Temperature, Ta(Deg. C)
Po
w
er
D
is
sp
at
ed
,P
d
(W
at
ts
)
0 10 20 30 40 50 60 70 80 90 100
20
25
30
35
40
45
50
Natural Convection
20 ft./min. (0.1 m/s)
100 ft./min. (0.5 m/s)
200 ft./min. (1.0 m/s)
300 ft./min. ( 1.5 m/s)
400 ft./min. (2.0 m/s)
500 ft./min. (2.5 m/s)
600 ft./min. (3.0 m/s)
700 ft./min. (3.5 m/s)
800 ft./min. (4.0 m/s)
Forced Convection Power Derating without Heat Sink
High Density DC-DC Modules