JC050B Lineage Power, JC050B Datasheet - Page 13

• Manufacturer Part Number: JC050B
• Description: CONVERTER DC/DC 12V 50W OUT
• Manufacturer: Lineage Power
• Series: JC050r
• Type: Isolated with Remote On/Offr

Specifications of JC050B

• Output: 12V
• Number Of Outputs: 1
• Power (watts): 50W
• Mounting Type: Through Hole
• Voltage - Input: 18 ~ 36V
• Package / Case: 9-DIP Module
• 1st Output: 12 VDC @ 4.2A
• Size / Dimension: 2.40" L x 2.28" W x 0.52" H (61mm x 57.9mm x 13.2mm)
• Power (watts) - Rated: 50W
• 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: -

Thermal considerations
Heat Transfer with Heat Sinks
Example
If an 85 °C case temperature is desired, what is the
minimum airflow necessary? Assume the JC100B
module is operating at nominal line and an output cur-
rent of 8.5 A, maximum ambient air temperature of
40 °C, and the heat sink is 0.5 in.
Solution
Given: V
Determine P
Then solve the following equation:
Use Figure 25 to determine air velocity for the0.5 inch
heat sink.
The minimum airflow necessary for the JC100B mod-
ule is 1.7 m/s (340 ft./min.).
θ
θ
θ
ca
ca
ca
March 2008
I
T
T
Heat sink = 0.5 in.
P
Lineage Power
O
=
=
=
A
C
I
D
= 28 V
= 8.5 A
= 40 °C
= 85 °C
= 20 W
2.3
D
(
----------------------- -
(
----------------------- -
T
85 40
by using Figure 24:
°C/W
C
P
20
–
–
D
T
A
)
)
(continued)
(continued)
18 Vdc to 36 Vdc Input, 12 Vdc Output; 50 W to 100 W
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 (θcs) and
sink-to-ambient (θsa) shown below (Figure 26).
Figure 26. Resistance from Case-to-Sink and
For a managed interface using thermal grease or foils,
a value of θcs = 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.
Layout Considerations
Copper paths must not be routed beneath the power
module mounting inserts.
θ
sa
P
=
D
→
(
------------------------ -
Sink-to-Ambient
T
C
P
T
–
D
C
T
A
)
–
θcs
θ
cs
T
S
θsa
T
A
8-1304
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