FC250A1 Lineage Power, FC250A1 Datasheet - Page 11

• Manufacturer Part Number: FC250A1
• Description: CONVERTER DC/DC 2.5V 100W OUT
• Manufacturer: Lineage Power
• Series: FC250r
• Type: Isolated with Remote On/Offr

Specifications of FC250A1

• Output: 2.5V
• Number Of Outputs: 1
• Power (watts): 50W
• Mounting Type: Through Hole
• Voltage - Input: 36 ~ 75V
• Package / Case: Module
• 1st Output: 2.5 VDC @ 40A
• Size / Dimension: 2.40" L x 2.28" W x 0.50" H (61mm x 57.9mm x 12.7mm)
• Power (watts) - Rated: 100W
• Operating Temperature: -40°C ~ 100°C
• Efficiency: 85%
• Approvals: CSA, UL, VDE
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• 3rd Output: -
• 2nd Output: -
• 4th Output: -

July 1998
Thermal Considerations
Heat Transfer Without Heat Sinks
Figure 16. FC250A1 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.).
Thermal derating with heat sinks is expressed by using
the overall thermal resistance of the module. Total
module thermal resistance ( ca) is defined as the max-
imum case temperature rise ( T
module power dissipation (P
The location to measure case temperature (T
shown in Figure 14. Case-to-ambient thermal resis-
tance vs. airflow is shown, for various heat sink config-
urations and heights, in Figure 17. These curves were
obtained by experimental testing of heat sinks, which
are offered in the product catalog.
Tyco Electronics Corp.
20
18
16
14
12
10
ca
8
6
4
2
4
=
6 8 10 12 14
Output Current at 25 °C
-------------------- -
T
P
C max
,
D
OUTPUT CURRENT, I
V
V
V
16 18 20 22 24 26 28 30 32 34 36 38 40
I
I
I
=
= 75 V
= 54 V
= 36 V
----------------------- -
T
D
C
):
P
–
D
C, max
T
A
(continued)
O
) divided by the
(A)
(continued)
C
) is
8-3400 (F)
18 Vdc to 36 Vdc Input, 5 Vdc Output; 50 W
Figure 17. FC250A1 Case-to-Ambient Thermal
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 Figure 17 had a
thermal-conductive dry pad between the case and the
heat sink to minimize contact resistance. The use of
Figure 17 is shown in the following example.
Example
If an 85 °C case temperature is desired, what is the
minimum airflow necessary? Assume the FC250A1
module is operating at V
of 26 A, maximum ambient air temperature of 55 °C,
and the heat sink is 1/4 inch.
Solution
Given: V
Determine P
8
7
6
5
4
3
2
1
0
I
T
T
Heat sink = 1/4 inch
P
0
O
A
C
I
D
= 54 V
= 26 A
= 55 °C
Resistance Curves; Either Orientation
= 85 °C
= 10 W
AIR VELOCITY MEASURED IN m/s (ft./min.)
D
(100)
by using Figure 16:
0.5
(200)
1.0
I
= 54 V and an output current
(300)
1.5
1 1/2 IN. HEAT SINK
1 IN. HEAT SINK
1/2 IN. HEAT SINK
1/4. HEAT SINK
NO HEAT SINK
(400)
2.0
(500)
2.5
(600)
8-3365.a
3.0
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