Datasheet
DS_E48SH12010_10212014
10
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 185mmX185mm,70μm (2Oz),6 layers 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’’).
AIR FLOW
MODULE
PWB
50.8(2.00")
AIR VELOCITY
AND AMBIENT
TEMPERATURE
SURED BELOW
THE MODULE
FANCING PWB
Note: Wind Tunnel Test Setup Figure Dimensions are in millimeters and (Inches)
Figure 21: 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.
THERMAL CURVES
(WITHOUT HEAT SPREADER)
Figure 22: Hot spot 1's temperature measured point.
＊
The allowed maximum hot spot temperature is defined at 123
℃
0
1
2
3
4
5
6
7
8
9
10
11
25 30 35 40 45 50 55 60 65 70 75 80 85
Output Current(A)
Ambient Temperature (℃)
E48SH12010(Standard) Output Current vs. Ambient Temperature and Air Velocity
@Vin = 48V (Transverse Orientation)
100LFM
200LFM
300LFM
Natural
Convection
400LFM
500LFM
Figure 23: Output current vs. ambient temperature and air velocity
@V
in
=48V (Transverse Orientation, airflow from Vin- to Vin+,
without heat spreader)