HW006/010/012 Series Power Modules; dc-dc Converters
36-75 Vdc Input; 1.2 Vdc to 5 Vdc Output; 6.6A to 12A
Data Sheet
June 26, 2009
12
10
Thermal Considerations
The power modules operate in a variety of thermal environ-
ments; however, sufficient cooling should be provided to help
ensure reliable operation of the unit. Heat is removed by con-
duction, convection, and radiation to the surrounding environ-
ment. Proper cooling can be verified by measuring drain pin
Q203 at the position indicated in Figure 43.
8
6
4
2
0
2.0 m/s (400 ft./min.)
1.0 m/s (200 ft./min.)
0.5 m/s (100 ft./min.)
NATURAL CONVECTION
The temperature at Q203 drain pins should not exceed 115
°C. The output power of the module should not exceed the
rated power for the module
(VO, set x IO, max).
20
30
40
50
60
70
80
90
Ambient Temperature T
A
(˚C)
Although the maximum operating ambient temperature of the
power modules is 85 °C, you can limit this temperature to a
lower value for extremely high reliability.
Figure 44. Derating Curves for HW010A0F1
(VO = 3.3 V) in Transverse Orientation
(VI = 48 Vdc).
8
7
6
5
4
3
2
1
0
2.0 m/s (400 ft./min.)
1.0 m/s (200 ft./min.)
0.5 m/s (100 ft./min.)
NATURAL CONVECTION
Attach thermocouple
to drain lead.
AIRFLOW
Figure 43. HW 6.6A-12A-Series Temperature
Measurement Location (Top View).
20
30
40
50
60
70
(˚C)
80
90
AMBIENT TEMPERATURE, T
A
Heat Transfer via Convection
Figure 45. Derating Curves for HW006A6A1
(VO = 5.0 V) in Transverse Orientation
(VI = 48 Vdc).
Increasing airflow over the module enhances the heat trans-
fer via convection. Figures 44—48 show the maximum cur-
rent that can be delivered by various modules versus local
ambient temperature (TA) for natural convection through 2 m/
s (400 ft./min.).
11
10
9
Systems in which these power modules may be used typi-
cally generate natural convection airflow rates of 0.3 ms–1
(60 ft./min.) due to other heat-dissipating components in the
system. Therefore, the natural convection condition repre-
sents airflow rates of up to 0.3 ms–1 (60 ft./min.). Use of Fig-
ure 44 is shown in the following example.
8
2.0 m/s (400 ft./min.)
1.0 m/s (200 ft./min.)
0.5 m/s (100 ft./min.)
7
6
NATURAL CONVECTION
5
4
3
Example
2
1
What is the minimum airflow necessary for a HW010A0F1
operating at VIN = 48 V, an output current of 10 A, and a
maximum ambient temperature of 75 °C.
0
20
30
40
50
60
70
80
90
AMBIENT TEMPERATURE, T
A
(˚C)
Solution
Figure 46. Derating Curves for HW010A0G1
Given: VIN = 48V
IO = 12 A
(VO = 2.5 V) in Transverse Orientation
(VI = 48 Vdc).
TA = 75 °C
Determine airflow (v) (Use Figure 44.):
v = 0.5 m/s (100 ft./min.)
Lineage Power
16
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
