MHB100 Datasheet, PDF (4/6 Pages) Mean Well Enterprises Co., Ltd. – 100W DC-DC Half-Brick Regulated Single Output Converter

M H B 1 0 0 ^{100W DC-DC Half-Brick Regulated Single Output Converter}
series
Thermal Curve
The operating case temperature range of MHB-100 series is -40^oC to +100^oC. When operate the MHB-100 series, proper de-rating or
cooling is needed.
The maximum case temperature under any operating condition should not be exceed 100^oC. The following curve is the de-rating
curve of MHB-100 series without heat sink.
50
45
40
35
30
25
20
15
10
5
0
0
Power Dissipated vs Amb ient Temperature and Air Flow without heatsink
10 20 30 40 50 60 70 80 90 100
Ambi ent Temperature, Ta ( )
Na tural Co nvection
20 ft. /min. (0.1 m/s)
100 f t./min. (0 .5 m/s)
200 f t./min. (1 .0 m/s)
300 f t./min. (1 .5 m/s)
400 f t./min. (2 .0 m/s)
500 f t./min. (2 .5 m/s)
600 f t./min. (3 .0 m/s)
700 f t./min. (3 .5 m/s)
800 f t./min. (4 .0 m/s)
Air Flow Rate
Natural convection
20ft./min. (0.1m/s)
100 ft./min. (0.5m/s)
200 ft./min. (1.0m/s)
300 ft./min. (1.5m/s)
400 ft./min. (2.0m/s)
Typical Rca
7.12 /W
6.21 /W
5.17 /W
4.29 /W
3.64 /W
Air Flow Rate
500 ft./min. (2.5m/s)
600 ft./min. (3.0m/s)
700 ft./min. (3.5m/s)
800 ft./min. (4.0m/s)
Typical Rca
2.96 /W
2.53 /W
2.37 /W
2.19 /W
Rca : Thermal resistance from case to
ambience
Example:
What is the minimum airflow necessary for a MHB100-48S12 operates at nominal line, an output current of 8.3A, and a maximum ambient
temperature of 40 ?
Solution:
Given: Vin=48Vdc, Vo=12Vdc, Io=8.3A, (unit efficiency)=89%
Determine Power dissipation (Pd):
Pd=Pi-Po=Po(1- )/
Pd=12 8.3 (1-0.89)/0.89=12.31 Watts
Determine airflow:
Given: Pd=12.31W and Ta=40
Check Thermal Curve above:
minimum airflow= 300 ft./min.
Verifying: The maximum temperature rise T = Pd Rca=12.31 4.29=52.8
The maximum case temperature Tc=Ta+ T=92.8 <100
Where: The Rca is thermal resistance from case to ambience.
The Ta is ambient temperature and the Tc is case temperature.
File Name:MHB100-SPEC 2011-09-08