d48s1238-2a Delta Electronics, Inc., d48s1238-2a Datasheet - Page 8

• Manufacturer Part Number: d48s1238-2a
• Description: Delphi Series D48s1238, 450w Quarter Brick Dc/dc Power Modules 48v In, 12v/38a Out
• Manufacturer: Delta Electronics, Inc.

DS_D48S1238-2_04142009
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
equipment. This type of equipment commonly uses
vertically mounted circuit cards in cabinet racks in which
the power modules are mounted.
The
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’’).
Figure 12: Wind tunnel test setup
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.
Note: Wind Tunnel Test Setup Figure Dimensions are in millimeters and (Inches)
MEASURED BELOW
following
TEMPERATURE
AIR VELOCITY
AND AMBIENT
THE MODULE
FACING PWB
encountered
figure
AIR FLOW
shows
in
PWB
50.8 (2.0”)
MODULE
12.7 (0.5”)
the
most
wind
electronics
tunnel
THERMAL CURVES
Figure 13: Temperature measurement location (open frame)
* The allowed maximum hot spot temperature is defined at 110
Figure 14: Temperature measurement location (with heatspreader)
* The allowed maximum hot spot temperature is defined at 90
Figure 15: Output current vs. ambient temperature and air velocity@
V
40
35
30
25
20
15
10
5
0
Input
in
25
Output Current (A)
=48V (Open frame, Transverse orientation)
100LFM
200LFM
300LFM
D48S1238-2 Output Current vs. Ambient Temperature and Air Velocity
35
@ Vin =48V, Open Frame(Transverse Orientation)
45
55
400LFM
65
500LFM
600LFM
Ambient Temperature (℃)
75
Output
℃
85
℃
.
.
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