Data Sheet
April 2008
JW050F, JW075F, JW100F, JW150F Power Modules:
dc-dc Converters; 36 to 75 Vdc Input, 3.3 Vdc Output; 33 W to 99 W
Note that the natural convection condition was mea-
sured at 0.05 m/s to 0.1 m/s (10 ft./min. to 20 ft./min.);
however, systems in which these power modules may
be used typically generate natural convection airflow
rates of 0.3 m/s (60 ft./min.) due to other heat dissipat-
ing components in the system. The use of Figure 31 is
shown in the following example.
Example
V
I
(+)
V
O
(+)
Thermal Considerations
(continued)
Introduction
(continued)
38.0 (1.50)
MEASURE CASE
TEMPERATURE HERE
7.6 (0.3)
ON/OFF
+ SEN
TRIM
What is the minimum airflow necessary for a JW100F
operating at V
I
= 54 V, an output current of 20 A, and a
maximum ambient temperature of 40 °C?
Solution
Given: V
I
= 54 V
I
O
= 20 A
T
A
= 40 °C
Determine P
D
(Use Figure 29.):
8-716 (C).f
CASE
– SEN
V
I
(–)
V
O
(–)
Note: Top view, pin locations are for reference only.
Measurements shown in millimeters and (inches).
P
D
= 15.8 W
Determine airflow (v) (Use Figure 31.):
v = 1.7 m/s (340 ft./min.)
Figure 26. Case Temperature Measurement
Location
The temperature at this location should not exceed
100 °C. The output power of the module should not
exceed the rated power for the module as listed in the
Ordering Information table.
Although the maximum case temperature of the power
modules is 100 °C, you can limit this temperature to a
lower value for extremely high reliability.
For additional information on these modules, refer to
the
Thermal Management JC-, JFC-, JW-, and JFW-
Series 50 W to 150 W Board-Mounted Power Modules
Technical Note
(TN97-008EPS).
9
8
7
V
I
= 75 V
6
5
4
3
2
0
1
2
3
4
5
6
O
V
I
= 54 V
V
I
= 36 V
7
(A)
8
9
10
OUTPUT CURRENT, I
8-1459 (C)
Heat Transfer Without Heat Sinks
Increasing airflow over the module enhances the heat
transfer via convection. Figure 31 shows the maximum
power that can be dissipated by the module without
exceeding the maximum case temperature versus local
ambient temperature (T
A
) for natural convection
through 4 m/s (800 ft./min.).
Figure 27. JW050F Power Dissipation vs.
Output Current
Lineage Power
13
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
