Q48SB10828NRFA Datasheet, PDF (7/11 Pages) Delta Electronics, Inc. – Delphi Series Q48SB, 300W Bus Converter DC/DC Power Modules: 48V in, 9.6V/31A 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
AIR VELOCITY
AND AMBIENT
TEMPERATURE
MEASURED BELOW
THE MODULE
AIR FLOW
50.8 (2.0”)
12.7 (0.5”)
Note: Wind Tunnel Test Setup Figure Dimensions are in millimeters and (Inches)
Figure 14: Wind tunnel test setup figure
Thermal Derating
Heat can be removed by increasing airflow over the
module. The module’s maximum hot spot temperature
is +124°C. 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 15: Hot spot temperature measured point
*The allowed maximum hot spot temperature is defined at 124℃
Q48SB10828NR (Standard) Output Current vs. Ambient Temperature and Air Velocity
Output Current (A)
35
@ Vin=48V (Transverse Orientation, Without Heat spreader)
30
25
Natural
Convection
20
100LFM
15
200LFM
10
300LFM
5
400LFM
500LFM
600LFM
0
25
35
45
55
65
75
85
Ambient Temperature (℃)
Figure 16: Output current vs. ambient temperature and air
velocity @V_in=48V(Transverse Orientation, without heat
spreader)
Q48SB10828NR (Standard) Output Current vs. Ambient Temperature and Air Velocity
Output Current (A)
35
@ Vin=48V (Longitudinal Orientation, Without Heat spreader)
30
25
Natural
Convection
20
100LFM
15
200LFM
10
300LFM
5
400LFM
500LFM
600LFM
0
25
35
45
55
65
75
85
Ambient Temperature (℃)
Figure 17: Output current vs. ambient temperature and air
velocity @V_in=48V (Longitudinal Orientation, without
heatspreader)
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