Product # PQ48018QNA25

Phone 1-888-567-9596

Doc.# 005-2QN418D_B

9/04/01

Page 5

Performance Curves

48Vin 1.8Vout 25A

Quarter

Quarter

Brick

Brick

0

5

10

15

20

25

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 7: Maximum output power-derating curves vs. ambient air tem-

perature for airflow rates of 0 LFM through 400 LFM with air flowing

lengthwise from output to input (nominal input voltage).

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

in the long direction from output to input (nominal input voltage).

Figure 9: Turn-on transient at full rated load current (resistive load) (2

ms/div)

Top Trace: Vout; 1V/div

Bottom Trace: ON/OFF input; 5V/div

Figure 10: Turn-on transient at zero load current (2 ms/div).

Top Trace: Vout; 1V/div

Bottom Trace: ON/OFF input; 5V/div

of Imax; dI/dt = 0.1A/µs). Load cap: 10µF, 100 m

1µF ceramic capacitor. Top trace: Vout (100mV/div), Bottom trace: Iout (5A/div).

of Imax: dI/dt = 5A/µs). Load cap: 470µF, 30 m

ceramic capacitor. Top trace: Vout (100mV/div), Bottom trace: Iout (5A/div).

Vin = 48V

Semiconductor junction temperature is

within 2

°C of surface temperature