H48SC3R325PSFA Datasheet, PDF (10/12 Pages) Delta Electronics, Inc. – Delphi Series H48SC3R325, 85W Half Brick Family DC/DC Power Modules: 48V in, 3.3V/25A out

THERMAL CONSIDERATIONS
Thermal management is an important part of the system
design. To ensure proper, reliable operation, sufficient
cooling of the power module is needed over the entire
temperature range of the module. Convection cooling is
usually the dominant mode of heat transfer.
Hence, the choice of equipment to characterize the
thermal performance of the power module is a wind
tunnel.
Thermal Testing Setup
Delta’s DC/DC power modules are characterized in
heated vertical wind tunnels that simulate the thermal
environments encountered in most electronics
equipment. This type of equipment commonly uses
vertically mounted circuit cards in cabinet racks in which
the power modules are mounted.
The following figure shows the wind tunnel
characterization setup. The power module is mounted
on a test PWB and is vertically positioned within the
wind tunnel. The space between the neighboring PWB
and the top of the power module is constantly kept at
6.35mm (0.25’’).
FACING PWB
PWB
MODULE
Thermal Derating
Heat can be removed by increasing airflow over the module.
To enhance system reliability, the power module should
always be operated below the maximum operating
temperature. If the temperature exceeds the maximum
module temperature, reliability of the unit may be affected.
THERMAL CURVES
Figure 21: Temperature measurement location
The allowed maximum hot spot temperature is defined at 116
H48SC3R325(Standard) Output Current vs. Ambient Temperature and Air Velocity
Output Current (A)
@Vin = 48V (Either Orientation)
25
Natural
Convection
20
15
AIR VELOCITY
AND AMBIENT
TEMPERATURE
MEASURED BELOW
10
THE MODULE
50.8 (2.0”)
AIR FLOW
5
12.7 (0.5”)
Note: Wind Tunnel Test Setup Figure Dimensions are in millimeters and (Inches)
Figure 20: Wind Tunnel Test Setup
0
25
30
35
40
45
50
55
60
65
70
75
80
85
Ambient Temperature ( )
Figure 22: Output current vs. ambient temperature and air
velocity @ Vin=48V (Either Orientation)
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