JW100G Lineage Power, JW100G Datasheet - Page 12

• Manufacturer Part Number: JW100G
• Manufacturer: Lineage Power

JW100G and JW150G Power Modules; dc-dc Converters:
36 Vdc to 75 Vdc Input, 2.5 Vdc Output; 50 W to 75 W
Thermal Considerations
Heat Transfer Without Heat Sinks
Increasing airflow over the module enhances the heat
transfer via convection. Figure 23 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 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 23 is
shown in the following example.
Example
What is the minimum airflow necessary for a JW150G
operating at V
maximum ambient temperature of 40 °C?
Solution
Given: V
Determine P
Determine airflow (v) (Use Figure 23.):
Figure 23. Forced Convection Power Derating with
12
12
35
30
25
20
15
10
5
0
0
I
T
P
v = 3.0 m/s (600 ft./min.)
O
A
I
D
0.1 m/s (NAT. CONV.)
= 55 V
= 30 A
= 40 °C
= 23.5 W
No Heat Sink; Either Orientation
10
D
LOCAL AMBIENT TEMPERATURE, T
I
(Use Figure 25.):
= 55 V, an output current of 30 A, and a
20
(20 ft./min.)
30
A
) for natural convection
40
50
60
(continued)
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 (500 ft./min.)
2.0 m/s (400 ft./min.)
1.5 m/s (300 ft./min.)
1.0 m/s (200 ft./min.)
0.5 m/s (100 ft./min.)
70
80
A
(°C)
8-1150 (F).a
90
100
Figure 24. JW100G Power Dissipation vs.
Figure 25. JW150G Power Dissipation vs.
Heat Transfer with Heat Sinks
The power modules have through-threaded, M3 x 0.5
mounting holes, which enable heat sinks or cold plates
to attach to the module. The mounting torque must not
exceed 0.56 N-m (5 in.-lb.).
For a screw attachment from the pin side, the recom-
mended hole size on the customer’s PWB around the
mounting holes is 0.130 ± 0.005 inches. If a larger hole
is used, the mounting torque from the pin side must not
exceed 0.25 N-m (2.2 in.-lb.).
25
20
15
10
5
0
18
16
14
12
10
0
8
6
4
2
0
1
Output Current
Output Current
3
5
V
V
V
I
I
I
= 75 V
= 48 V
= 36 V
5
OUTPUT CURRENT, I
OUTPUT CURRENT, I
7
10
9
V
V
V
11
15
I
I
I
= 36 V
= 55 V
= 75 V
13
20
15
O
O
(A)
(A)
Lineage Power
March 2008
Data Sheet
17
25
19
8-1944 (F)
21
1-0061
30