Data Sheet
June 27, 2012
EBVW025A0B Series Power Modules; DC-DC Converters
36-75Vdc Input; 12Vdc Output; 25A Output Current
Solution:
Feature Descriptions (continued)
Given: Vin= 48V, IO = 14A, TA = 70 °C
Determine required airflow (V) (Use Figure 20):
V = 200LFM or greater.
Heat-dissipating components are mounted on the top side
of the module. Heat is removed by conduction, convection
and radiation to the surrounding environment. Proper
cooling can be verified by measuring the thermal reference
temperature (THx). Peak temperature (THx) occurs at the
position indicated in Figure 18 and 19. For reliable
operation this temperature should not exceed the listed
temperature threshold.
LOCAL AMBIENT TEMPERATURE, TA (C)
Figure 18. Location of the thermal reference
temperature TH1. Do not exceed 113 °C.
Figure 20. Output Current Derating for the Open
Frame EBVW025A0B in the Transverse Orientation;
Airflow Direction from Vin(-) to Vin(+); Vin = 48V.
Figure 19. Location of the thermal reference
temperature TH2 for Base Plate module. Do not exceed
110 °C.
The output power of the module should not exceed the
rated power for the module as listed in the Ordering
Information table.
LOCAL AMBIENT TEMPERATURE, TA (C)
Figure 21. Output Current Derating for the Base Plate
EBVW025A0Bxx-H in the Transverse Orientation;
Airflow Direction from Vin(-) to Vin(+); Vin = 48V.
Although the maximum temperature of the power modules
is THx, you can limit this temperature to a lower value for
extremely high reliability.
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.
Heat Transfer via Convection
Increased airflow over the module enhances the heat
transfer via convection. The thermal derating of figures 20
through 22 show the maximum output current that can be
delivered by each module in the indicated orientation
without exceeding the maximum THx temperature versus
local ambient temperature (TA) for air flows of, Natural
Convection, 1 m/s (200 ft./min), 2 m/s (400 ft./min).
The use of Figures 20 is shown in the following example:
LOCAL AMBIENT TEMPERATURE, TA (C)
Example
Figure 22. Output Current Derating for the Base Plate
EBVW025A0Bxx-H and 0.25” heat sink in the
Transverse Orientation; Airflow Airflow Direction
from Vin(-) to Vin(+); Vin = 48V.
What is the minimum airflow necessary for a
EBVW025A0B operating at VI = 48 V, an output current of
14A, and a maximum ambient temperature of 70 °C in
transverse orientation.
LINEAGE POWER
10
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
