Data Sheet
JRW017-070 Series Power Modules DC-DC Converters
36-75Vdc Input; 1.2Vdc to 12Vdc Output
July 21, 2008
Note that the natural convection condition was
measured at 0.05 m/s to 0.1 m/s (10ft./min. to 20
ft./min.); however, systems in which these power
modules may be used typically generate natural
convection airflow rates of 0.3 m/s (60 ft./min.) due to
other heat dissipating components in the system. The
use of Figures 53 - 59 are shown in the following
example:
70
60
50
40
30
20
10
0
2.0 m/s (400 ft./min)
1.0 m/s (200 ft./min)
Natural Convection
Example
What is the minimum airflow necessary for a
JRW060A0F operating at VI = 48 V, an output current
of 42A, and a maximum ambient temperature of 70 °C
in transverse orientation.
20
30
40
50
60
70
80
90
Solution:
LOCAL AMBIENT TEMPERATURE, TA (°C)
Given: VI = 48V
Figure 55. Output Power Derating for JRW060A0F (Vo
= 3.3V) in Transverse Orientation with no baseplate;
Airflow Direction From Vin(+) to Vin(-); Vin = 48V.
70
Io = 48A
TA = 70 °C
Determine airflow (V) (Use Figure 53):
V = 1m/sec. (200ft./min.)
60
50
20
18
16
14
12
40
2.0 m/s (400 ft./min)
30
1.0 m/s (200 ft./min)
20
10
2.0 m/s (400 ft./min)
8
Natural Convection
10
6
1.0 m/s (200 ft./min)
0
4
20
30
40
50
60
70
80
90
Natural Convection
2
0
LOCAL AMBIENT TEMPERATURE, TA (°C)
20
30
40
50
60
70
80
90
Figure 56. Output Power Derating for JRW065A0G (Vo
= 2.5V) in Transverse Orientation with no baseplate;
LOCAL AMBIENT TEMPERATURE, TA (°C)
Airflow Direction From Vin(+) to Vin(-); Vin = 48V.
Figure 53. Output Power Derating for JRW017A0B
(Vo = 12V) in Transverse Orientation with no
baseplate; Airflow Direction From Vin(+) to Vin (-);
Vin = 48V.
70
60
50
40
50
45
40
35
2.0 m/s (400 ft./min)
30
1.0 m/s (200 ft./min)
20
30
Natural Convection
10
2.0 m/s (400 ft./min)
25
20
0
1.0 m/s (200 ft./min)
15
20
30
40
50
60
70
80
90
10
Natural Convection
5
0
LOCAL AMBIENT TEMPERATURE, TA (°C)
Figure 57. Output Power Derating for JRW065A0Y (Vo
= 1.8V) in Transverse Orientation with no baseplate;
Airflow Direction From Vin(+) to Vin(-); Vin = 48V.
20
30
40
50
60
70
80
90
LOCAL AMBIENT TEMPERATURE, TA (°C)
Figure 54. Output Power Derating for JRW040A0A
(Vo = 5V) in Transverse Orientation with no
baseplate; Airflow Direction From Vin(+) to Vin (-);
Vin = 48V.
LINEAGE POWER
19
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
