GE Industrial Solutions 12V TLynx 20A - Manual (Page 19)

GE
Data Sheet
12V TLynx TM 20A: Non-Isolated DC-DC Power Modules
4.5Vdc –14Vdc input; 0.69Vdc to 5.5Vdc output; 20A Output Current
May 2, 2013 ©2013 General Electric Company. All rights reserved. Page 19
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 49. The preferred airflow direction
for the module is in Figure 50. The derating data applies to
airflow in either direction of the module’s long axis.
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)
Figure 49. Thermal Test Setup.
The thermal reference points, T
ref
used in the specifications are
also shown in Figure 50. 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 50. Preferred airflow direction and location of
hot-spot of the module (Tref).
Modules marked ruggedized with a “D” suffix operate up
to an ambient of 105
°C. For the remaining types de-
rating curves for individual output voltages meet existing
specifications up to 85
°C.