Product # PQ60025QGA25
Phone 1-888-567-9596
Doc.# 005-2QG625D Rev. B
6/26/02
Page 5
Performance Curves
48Vin 2.5Vout 25A
Quarter
Brick
60
65
70
75
80
85
90
0
3
5
8
10131518
202325
Load Current (A)
Efficiency
(%)
36 Vin
48 Vin
75 Vin
Figure 1: Efficiency at nominal output voltage vs. load current for min-
imum, nominal, and maximum input voltage at 25°C.
82
83
84
85
86
87
88
89
90
0
100
200
300
400
500
Air Flow (LFM)
Efficiency
(
%
)
25 C
40 C
55 C
Figure 2: Efficiency at nominal output voltage and 60% rated power vs.
airflow rate for ambient air temperatures of 25°C, 40°C, and 55°C
(nominal input voltage).
0
2
4
6
8
10
12
0
3
5
8
10
13
15
18
20
23
25
Load Current (A)
Power
Dissipation
(W)
36 Vin
48 Vin
75 Vin
Figure 3: Power dissipation at nominal output voltage vs. load current
for minimum, nominal, and maximum input voltage at 25°C.
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
0
100
200
300
400
500
Air Flow (LFM)
Power
Dissipation
(
W
)
25 C
40 C
55 C
Figure 4: Power dissipation at nominal output voltage and 60% rated
power vs. airflow rate for ambient air temperatures of 25°C, 40°C, and
55°C (nominal input voltage).
0
5
10
15
20
25
0
2540
5570
85
Ambient Air Temperature (oC)
Iout
(A)
400 LFM (2.0 m/s)
300 LFM (1.5 m/s)
200 LFM (1.0 m/s)
100 LFM (0.5 m/s)
0 LFM (0 m/s)
Figure 5: Maximum output power derating curves vs. ambient air tem-
perature for airflow rates of 0 LFM through 400 LFM with air flowing
across the converter from pin 3 to pin 1 (nominal input voltage).
Figure 6: Thermal plot of converter at 25 amp load current with 55°C
air flowing at the rate of 200 LFM. Air is flowing across the converter
sideways from pin 3 to pin 1 (nominal input voltage).
Semiconductor junction temperature is
within 1
°C of surface temperature