JFW100B Lineage Power, JFW100B Datasheet - Page 16

• Manufacturer Part Number: JFW100B
• Manufacturer: Lineage Power

dc-dc Converters; 36 to 75 Vdc Input, 12 Vdc Output; 50 W to 150 W
Thermal Considerations
Introduction
Note: Top view, measurements shown in millimeters and (inches).
Figure 27. Case Temperature Measurement
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 regarding this module, refer to
the Thermal Management JC-, JFC-, JW-, and JFW-
Series 50 W to 150 W Board-Mounted Power Modules
Technical Note (TN97-008EPS).
Heat Transfer Without Heat Sinks
Increasing airflow over the module enhances the heat
transfer via convection. Figure 28 shows the maximum
power that can be dissipated by the module without
exceeding the maximum case temperature versus local
ambient temperature (T
through 4 m/s (800 ft./min.).
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 this power module may be
used typically generate a natural convection airflow
rate of 0.3 m/s (60 ft./min.) due to other heat dissipating
components in the system. The use of Figure 28 is
shown in the following example.
16
16
7.6 (0.30)
Pin locations are for reference only.
Location
38.0 (1.50)
(continued)
A
) for natural convection
(continued)
TEMPERATURE HERE
MEASURE CASE
8-1397 (C).a
Example
What is the minimum airflow necessary for a JFW150B
operating at V
maximum ambient temperature of 40 °C?
Solution
Given: V
Determine P
Determine airflow (v) (Use Figure 28.):
Figure 28. Forced Convection Power Derating with
Figure 29. JFW050B Power Dissipation vs.
10
9
8
7
6
5
4
3
2
1
0
35
30
25
20
15
10
0.5
5
0
0
I
T
P
v = 2.0 m/s (400 ft./min.)
O
A
I
D
= 10 A
= 54 V
1.0
= 40 °C
0.1 m/s (NAT. CONV.)
10
= 17 W
No Heat Sink; Either Orientation
Output Current at 25 °C
D
I
LOCAL AMBIENT TEMPERATURE, T
(Use Figure 32.):
= 54 V, an output current of 10 A, and a
20
1.5
OUTPUT CURRENT, I
(20 ft./min.)
30
2.0
40
2.5
50
3.0
60
V
V
V
O
I
I
I
= 75 V
= 54 V
= 36 V
(A)
4.0 m/s (800 ft./min
3.5 m/s (700 ft./min
3.0 m/s (600 ft./min
2.5 m/s
2.0 m/s
1.5 m/s (300 ft./min
1.0 m/s (200 ft./min
0.5 m/s (100 ft./min
3.5
70
Lineage Power
(500 ft./min
(400 ft./min
A
April 2008
80
(˚C)
4.0
90
8-1150 (C).a
4.5
8-2550 (C)
100