Thermal considerations – GE Industrial Solutions Austin MegaLynx SMT User Manual

Page 20

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Data Sheet
September 10, 2013

Austin MegaLynx

TM

SMT: Non-Isolated DC-DC Power Modules:

4.5 – 5.5Vdc input; 0.8 to 3.63Vdc Output; 30A output current

6.0 – 14Vdc Input; 0.8Vdc to 3.63Vdc Output; 20/30A output

LINEAGE

POWER

20

Thermal Considerations

Power modules operate in a variety of thermal
environments; however, sufficient cooling should
always be provided to help ensure reliable
operation.

Considerations include ambient temperature,
airflow, module power dissipation, and the need for
increased reliability. A reduction in the operating
temperature of the module will result in an increase
in reliability. The thermal data presented here is
based on physical measurements taken in a wind
tunnel. The test set-up is shown in Figure 54. Note
that the airflow is parallel to the short axis of the
module as shown in Figure 55. The derating data
applies to airflow in either direction of the module’s
long axis.

Figure 54. Thermal Test Setup.

The thermal reference points, T

ref

used in the

specifications are shown in Figure 56. For reliable
operation the temperatures at these points should
not exceed 125

o

C. The output power of the module

should not exceed the rated power of the module
(Vo,set x Io,max).

Please refer to the Application Note “Thermal
Characterization Process For Open-Frame Board-
Mounted Power Modules” for a detailed discussion
of thermal aspects including maximum device
temperatures.

Figure 55. Airflow direction for thermal testing.

Figure 56. Tref Temperature measurement

location.



Air

flow

x

Power Module

Wind Tunnel

PWBs

12.7_

(0.50)

76.2_

(3.0)

Probe Location
for measuring
airflow and
ambient
temperature

25.4_

(1.0)

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