Heat transfer via convection – GE Industrial Solutions HW006-010-012 Series User Manual

Page 16

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Lineage Power

16

Data Sheet
June 26, 2009

36-75 Vdc Input; 1.2 Vdc to 5 Vdc Output; 6.6A to 12A

HW006/010/012 Series Power Modules; dc-dc Converters

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.

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).

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 43. HW 6.6A-12A-Series Temperature

Measurement Location (Top View).

Heat Transfer via Convection

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.).

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.

Example

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.

Solution

Given:

VIN = 48V
IO = 12 A
TA = 75 °C

Determine airflow (v) (Use Figure 44.):

v = 0.5 m/s (100 ft./min.)

Figure 44. Derating Curves for HW010A0F1

(VO = 3.3 V) in Transverse Orientation
(VI = 48 Vdc).

Figure 45. Derating Curves for HW006A6A1

(VO = 5.0 V) in Transverse Orientation
(VI = 48 Vdc).

Figure 46. Derating Curves for HW010A0G1

(VO = 2.5 V) in Transverse Orientation
(VI = 48 Vdc).

Q203

Attach thermocouple
to drain lead.

AIRFLOW

0

2

4

6

8

10

12

20

30

40

50

60

70

80

90

Ambient Temperature T

A

(˚C)

Output Current I

O

(A)

2.0 m/s (400 ft./min.)

1.0 m/s (200 ft./min.)

0.5 m/s (100 ft./min.)

NATURAL CONVECTION

0

1

2

3

4

5

6

7

8

20

30

40

50

60

70

80

90

AMBIENT TEMPERATURE, T

A

(˚C)

OUTPUT CURRENT

, I

O

(A)

2.0 m/s (400 ft./min.)
1.0 m/s (200 ft./min.)
0.5 m/s (100 ft./min.)

NATURAL CONVECTION

0

1

2

3

4

5

6

7

8

9

10

11

20

30

40

50

60

70

80

90

AMBIENT TEMPERATURE, T

A

(˚C)

OUTPUT CURRENT

, I

O

(A)

2.0 m/s (400 ft./min.)
1.0 m/s (200 ft./min.)
0.5 m/s (100 ft./min.)

NATURAL CONVECTION

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