dw025 Lineage Power, dw025 Datasheet - Page 15

• Manufacturer Part Number: dw025
• Description: Dw025 Dual Output-series Power Modules Dc-dc Converters
• Manufacturer: Lineage Power

Data Sheet
April 2008
Thermal Considerations
Air Velocity
Figure 20. Total Power Dissipation vs. Local
Figure 21. Case-to-Ambient Thermal Resistance vs.
Lineage Power
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0
CONV
NAT
40
2.03 ms
1.02 ms
0.51 ms
0.31 ms
Ambient Temperature and Air Velocity
Air Velocity
0.25
(50)
LOCAL AMBIENT TEMPERATURE, T
50
–1
–1
–1
CONVECTION
(continued)
–1
(400 ft./min)
(200 ft./min)
(100 ft./min)
(100)
0.51
(60 ft./min)
NATURAL
VELOCITY ms
60
(150)
0.76
(200)
1.02
70
–1
(ft./min.)
DW025 Dual Output-Series Power Modules: dc-dc Converters;
(continued)
(250)
1.27
80
(300)
1.52
A
( C)
90
(350)
1.78
8-988(C)
8-989(C)
(400)
2.03
100
36 Vdc to 75 Vdc Input; Dual Outputs; 25 W
Use of Heat Sinks and Cold Plates
The DW025-Series case includes through-threaded
M3 x 0.5 mounting holes allowing attachment of heat
sinks or cold plates from either side of the module. The
mounting torque must not exceed 0.56 N/m (5 in.-lb.).
The following thermal model can be used to determine
the required thermal resistance of the sink to provide
the necessary cooling:
where P
represents the interfacial contact resistance between
the module and the sink, and
thermal impedance (°C/W). For thermal grease or foils,
a value of
The required
tion:
Note that this equation assumes that all dissipated
power must be shed by the heat sink. Depending on
the user-defined application environment, a more accu-
rate model including heat transfer from the sides and
bottom of the module can be used. This equation pro-
vides a conservative estimate in such instances.
For further information, refer to the Thermal Energy
Management CC-, CW-, DC-, and DW-Series 25 W
to 30 W Board-Mounted Power Modules Technical
Note.
P
D
D
Tc
is the power dissipated by the module,
l
CS
= 0.1 °C/W—0.3 °C/W is typical.
SA
SA
is calculated from the following equa-
= [(Tc – T
CS
A
)/P
Ts
SA
D
is the sink-to-ambient
] –
CS
SA
15
CS
T
A