FW250H1 Lineage Power, FW250H1 Datasheet - Page 16

• Manufacturer Part Number: FW250H1
• Description: CONVERTER DC/DC 24V 250W OUT
• Manufacturer: Lineage Power
• Series: FW250r
• Type: Isolated with Remote On/Offr

Specifications of FW250H1

• Output: 24V
• Number Of Outputs: 1
• Power (watts): 250W
• Mounting Type: Through Hole
• Voltage - Input: 36 ~ 75V
• Package / Case: Module
• 1st Output: 24 VDC @ 10.4A
• Size / Dimension: 4.60" L x 2.40" W x 0.53" H (116.8mm x 61mm x 13.5mm)
• Power (watts) - Rated: 250W
• Operating Temperature: -40°C ~ 100°C
• Efficiency: 89%
• Approvals: CE, CSA, UL, VDE
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• 3rd Output: -
• 2nd Output: -
• 4th Output: -

Data Sheet
September 2001
Thermal Considerations
Heat Transfer with Heat Sinks
Example
If an 85 °C case temperature is desired, what is the
minimum airflow necessary? Assume the FW250H1
module is operating at nominal line and an output cur-
rent of 10 A, maximum ambient air temperature of
40 °C, and the heat sink is 1/2 inch.
Solution
Given: V
Determine P
Then solve the following equation:
Use Figures 23 and 24 to determine air velocity for the
1/2 inch heat sink. The minimum airflow necessary for
the FW250H1 module depends on heat sink fin orienta-
tion and is shown below:
Custom Heat Sinks
A more detailed model can be used to determine the
required thermal resistance of a heat sink to provide
necessary cooling. The total module resistance can be
separated into a resistance from case-to-sink ( cs) and
sink-to-ambient ( sa) as shown in Figure 27.
Tyco Electronics Corp.
1.25 m/s (250 ft./min.) (oriented along width)
1.5 m/s (300 ft./min.) (oriented along length)
ca
ca
ca
I
T
T
Heat sink = 1/2 inch.
P
O
=
=
=
A
C
I
D
= 10 A
= 55 V
= 40 °C
= 85 °C
= 28 W
1.61 °C/W
D
----------------------- -
----------------------- -
T
85 40
by using Figure 25:
C
P
28
–
–
D
T
A
(continued)
FW250H1 and FW300H1 Power Modules; dc-dc Converters:
(continued)
36 Vdc to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W
Figure 27. Resistance from Case-to-Sink and Sink-
For a managed interface using thermal grease or foils,
a value of cs = 0.1 °C/W to 0.3 °C/W is typical. The
solution for heat sink resistance is:
This equation assumes that all dissipated power must
be shed by the heat sink. Depending on the user-
defined application environment, a more accurate
model, including heat transfer from the sides and bot-
tom of the module, can be used. This equation pro-
vides a conservative estimate for such instances.
EMC Considerations
For assistance with designing for EMC compliance,
please refer to the FLTR100V10 data sheet
(FDS01-043EPS)
Layout Considerations
Copper paths must not be routed beneath the power
module mounting inserts. For additional layout guide-
lines, refer to the FLTR100V10 data sheet
(FDS01-043EPS)
sa
=
P
D
to-Ambient
------------------------ -
T
C
P
T
–
C
D
T
A
–
cs
cs
T
S
sa
T
A
8-1304
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