Q48SB9R650NRFA Datasheet, PDF (9/12 Pages) Delta Electronics, Inc. – Delphi Series Q48SB, 500W Bus Converter DC/DC Power Modules: 48V in, 9.6V/55A 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”)
THERMAL CURVES
Figure 17: Hot spot temperature measured point
*The allowed maximum hot spot temperature is defined at 124℃
Q48SB9R650(Standard) Output Current vs. Ambient Temperature and Air Velocity
Output Current(A) _{@Vin = 48V (Transverse Orientation, From Pin 4 to Pin 7, Preliminary Derating Curve)}
50
400LFM
45
40
35
Natural
Convection
30
25
100LFM
200LFM
20
300LFM
15
10
5
0
20
25
30
35
40
45
50
55
60
65
70 _{Ambi7e5nt Tempe8r0ature (℃}8) 5
Figure 18: Output current vs. ambient temperature and air
velocity@ V_in=48V(Transverse orientation, from pin 4 to pin 7,
preliminary derating curve, without heatspreader)
12.7 (0.5”)
Note: Wind Tunnel Test Setup Figure Dimensions are in millimeters and (Inches)
Figure 16: Wind tunnel test setup
Thermal Derating
Heat can be removed by increasing airflow over the
module. The module’s maximum hot spot temperature is
124℃. 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.
TBD
Figure 19: Output current vs. ambient temperature and air
velocity@ V_in=48V(Transverse Orientation, with heat spreader)
DS_Q48SB9R650_07102006
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