Design Guide & Applications Manual
For VI-200 and VI-J00 Family DC-DC Converters and Configurable Power Supplies
VI-200 and VI-J00 Family Design Guide
Rev 3.4
vicorpower.com
Page 67 of 97
Apps. Eng. 800 927.9474
800 735.6200
Example 3.
Determine the maximum ambient temperature
of a 3-up FlatPAC delivering 12 V at 600 W in 500 LFM
with no additional conduction cooling to the chassis.
Maximum ambient temp. = T
max
–
θ
sa
x P
out
(
1
– 1
)
η
T
max
= 85°C
θ
sa
= 0.3°C/W
P
out
= 600 W
η
= 85% = (0.85)
Maximum ambient temp. = 85 – 0.3 x 600
(
1
– 1
)
0.85
= 53°C
Example 4.
Determine the temperature rise of a
150 W, VI-200 converter delivering 5 V at 132 W
with a Part #30090 heat sink in 200 LFM.
Temperature rise =
θ
sa
x P
out
(
1
– 1
)
η
θ
sa
= 1.1°C/W
P
out
= 132 W
η
= 81% = (0.81)
Temperature rise = 1.1 x 132
(
1
– 1
)
0.81
= 34˚C Over ambient temperature
Example 5.
Determine the baseplate to coldplate thermal
drop for an MI-200 converter delivering 5 V at 50 W with
a thermal pad.
Thermal drop =
θ
bs
x P
out
(
1
– 1
)
η
θ
bs
= 0.2°C/W
P
out
= 50 W
η
= 81% = 0.81
Temperature rise = 0.2 x 50
(
1
– 1
)
0.81
= 2.34˚C
20. Thermal and Module Mounting Considerations
Summary of Contents for VI-200 Series
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