Delta Electronics S48SR - Manual (Page 10)

DS_S48SR12001_07052006
10
Note: Wind Tunnel Test Setup Figure Dimensions are in millimeters and (Inches)
10 (0.4”)
MODULE
AIR FLOW
50.8 (2.0”)
FACING PWB PWB
AIR VELOCITY
AND AMBIENT
TEMPERATURE
MEASURED BELOW
THE MODULE
Figure 20:
Wind tunnel test setup
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
or a heat sink is 6.35mm (0.25”).
Thermal Derating
Heat can be removed by increasing airflow over the
module. Figure 13, 14, 17 and 18 show maximum
output is a function of ambient temperature and
airflow rate. The module’s maximum case
temperature is +100°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
.