FW330 Lineage Power, FW330 Datasheet - Page 20

• Manufacturer Part Number: FW330
• Description: Fw330 Power Modules Dc-dc Converters 36 To 75 Vdc Input, 3.6, 3.3, 2.5, 2.0, Or 1.8 Vdc Output; 180 W To 330 W
• Manufacturer: Lineage Power

36 to 75 Vdc Input, 3.6, 3.3, 2.5, 2.0, or 1.8 Vdc Output; 180 W to 330 W
Thermal Considerations
Heat Transfer with Heat Sinks
Figures 32 and 33 can be used to predict which heat
sink a module will require in a natural convection envi-
ronment.
For example when a module is transversely oriented in
a 20 °C ambient and dissipates 50 W, then a 1.5 in.
heat sink is required.
Thermal derating with heat sinks is expressed by using
the overall thermal resistance of the module. Total
module thermal resistance (θca) is defined as the max-
imum case temperature rise (ΔT
module power dissipation (P
The location to measure case temperature (T
shown in Figure 29. Case-to-ambient thermal resis-
tance vs. airflow for various heat sink configurations is
shown in Figure 34 and 35. These curves were
obtained by experimental testing of heat sinks, which
are offered in the product catalog.
Figure 34. Case-to-Ambient Thermal Resistance
20
20
θ
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
ca
0.0
(0)
=
Curves; Transverse Orientation
ΔT
-------------------- -
P
C max
,
D
AIR VELOCITY m/s (ft /min )
(200)
1.0
=
(
----------------------- -
NO HEAT SINK
1/ 4 IN. HEAT SINK
1/ 2 IN. HEAT SINK
1 IN. HEAT SINK
1 1/ 2 IN. HEAT SINK
T
D
C
):
P
–
D
C, max
T
A
(continued)
)
(400)
) divided by the
2.0
(continued)
C
) is
8-2610 (C)
(600)
3.0
Figure 35. Case-to-Ambient Thermal Resistance
These measured resistances are from heat transfer
from the sides and bottom of the module as well as the
top side with the attached heat sink; therefore, the
case-to-ambient thermal resistances shown are gener-
ally lower than the resistance of the heat sink by itself.
The module used to collect the data in Figures 34 and
35 had a thermal-conductive dry pad between the case
and the heat sink to minimize contact resistance.
To choose a heat sink, determine the power dissipated
as heat by the unit for the particular application.
Figures 37 through 40 show typical heat dissipation for
a range of output currents and three voltages for the
FW330 modules.
Figure 36. FW330S3R671-56 Power Dissipation vs.
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
90
80
70
60
50
40
30
20
10
0.0
(0)
0
9
Curves; Longitudinal Orientation
Output Current at 25 °C
19
29
AIR VELO CITY, m/s (ft./min.)
V
V
V
OUTPUT CURRENT, I
I
I
(200)
I
1.0
= 75 V
= 36 V
= 48 V
39
NO HEAT SINK
1/4 IN. HEAT SI NK
1/2 IN. HEAT SI NK
1 IN. HEAT SI NK
1 1/2 IN. HEAT SINK
49
59
(400)
2.0
69
O
April 3, 2008
(A)
Lineage Power
79
89
8-3016 (F)
8-2611(C)
(600
99
3.0