GE Industrial Solutions QW010-015-020 Series - Manual (Page 16)

Tyco Electronics Power Systems 16
Data Sheet
August 22, 2006
36 Vdc to 75 Vdc Input; 1.2 Vdc to 5.0 Vdc Output; 10 A to 20 A
QW010/015/020 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
of Q560 or of Q10 at the position indicated in Figure 44.
The temperature at Q560 and Q10 drain pins should not
exceed 110 °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 44. Temperature Measurement
Location,QW015A0F (Top View).
Heat Transfer via Convection
Increasing airflow over the module enhances the heat trans-
fer via convection. Figures 45—55 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.).
Example
What is the minimum airflow necessary for a QW015A0F1
operating at VIN = 48 V, an output current of 12 A, and a
maximum ambient temperature of 75 °C.
Solution
Given: VIN = 48V
IO = 12 A
TA = 75 °C
Determine airflow (v) (Use Figure 52)
v = 0.5 m/s (100 ft./min.)
Figure 45. Derating Curves for QW010A0A1 (VO = 5.0V)
in Longitudinal Orientation with no heat sink
(VI = 48 Vdc).
Figure 46. Derating Curves for QW010A0F1 (VO = 3.3V)
in Longitudinal Orientation with no heat sink
(VI = 48 Vdc).
Figure 47. Derating Curves for QW010A0G1 (VO = 2.5V)
in Longitudinal Orientation with no heat sink
(VI = 48 Vdc).
AIRFLOW
Q560
Q10
10
8
6
4
2
0
OUTPUT CURRENT
, I
O
(A)
25 35 45 55 65 75 85
LOCAL AMBIENT TEMPERATURE, T A (˚C)
2.0 m/s (400 ft./min.)
1.0 m/s (200 ft./min.)
0.5 m/s (100 ft./min.)
NATURAL CONVECTION
0
2
4
6
8
10
12
14
16
20 30 40 50 60 70 80 90
Local 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
5
10
15
20
25 30 35 40 45 50 55 60 65 70 75 80 85
LOCAL 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