DS_H48SA53010_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 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’’).

Thermal De-rating

Heat can be removed by increasing airflow over the module.

The module

’s maximum device temperature is to be defined

and the measured location is illustrated in Figure 19.

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)

12.7 (0.5”)

MODULE

AIR FLOW

50.8 (2.0”)

FACING PWB

PWB

AIR VELOCITY

AND AMBIENT

TEMPERATURE

MEASURED BELOW

THE MODULE

Figure 19: Wind tunnel test setup

THERMAL CURVES

(WITH HEATSPREADER)

Figure 20: Temperature measurement location *

The allowed maximum hot spot temperature is defined at 108

℃

H48SA53010(Standard) Output Power vs. Ambient Temperature and Air Velocity

@Vin = 48V (Either Orientation,With Heatspreader)

0

50

100

150

200

250

300

350

400

450

500

550

25

30

35

40

45

50

55

60

65

70

75

80

85

Natural

Convection

100LFM

300LFM

200LFM

Ambient Temperature (℃)

Output Power (W)

600LFM

500LFM

400LFM

Figure 21: Output Power vs. ambient temperature and air velocity