60

65

70

75

80

85

90

95

100

0

2

4

6

8

1012

1416

1820

Load Current (A)

36 Vin

48 Vin

75 Vin

Product # PQ48025HKA20

Phone 1-888-567-9596

Doc.# 005-2HK425G Rev. C

4/9/03

Page 5

82

83

84

85

86

87

88

89

90

0

100

200

300

400

500

Air Flow (LFM)

25 C

40 C

55 C

Figure 2: Efficiency at nominal output voltage and 60% rated power vs.

(nominal input voltage).

0

1

2

3

4

5

6

7

8

0

2

4

6

8

10

12

14

16

18

20

Load Current (A)

36 Vin

48 Vin

75 Vin

Figure 3: Power dissipation at nominal output voltage vs. load current

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

0

100

200

300

400

500

Air Flow (LFM)

25 C

40 C

55 C

Figure 4: Power dissipation at nominal output voltage and 60% rated

0

2

4

6

8

10

12

14

16

18

20

0

2540

5570

85

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

from output to input (nominal input voltage).

air flowing at the rate of 200 LFM. Air is flowing across the converter

from output to input (nominal input voltage).

Half

Half

Brick

Brick

Performance Curves

48Vin 2.5Vout 20A

Figure 1: Efficiency at nominal output voltage vs. load current for min-