Product # DQ63318QGL08

Phone 1-888-567-9596

Doc.# 005-2DQ638D Rev. B

10/7/03

Page 8

Performance Curves

48Vin 3.3/1.8Vout 77W

Quarter

Quarter

Brick Dual

Brick Dual

Figure 23: Load current for 1.8V output (20A/div) as a function of time

when the converter attempts to turn on into a 10 m

Ω short circuit.

Bottom trace is an expansion of the on-time portion of the top trace.

Figure 24: Load current for 3.3V output (20A/div) as a function of time

when the converter attempts to turn on into a 10 m

Ω short circuit.

Bottom trace is an expansion of the on-time portion of the top trace.

inductor at nominal input voltage and rated load current (5 mA/div).

1.8V and 3.3V outputs at full rated load current. (see Fig. 17)

Figure 20: Output Voltage Ripple at nominal input voltage and rated

0.0

0.5

1.0

1.5

2.0

2.5

0

5

10

15

20

35 V

48 V

75 V

Figure 21: Output voltage vs. load current showing typical current limit

curves and converter shutdown points for the 1.8V output. 3.3V load is

at 0A.

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

0

5

10

15

20

35 V

48 V

75 V

Figure 22: Output voltage vs. load current showing typical current limit

curves and converter shutdown points for the 3.3V output. 1.8V load is

at 0A.

1.8Vout

3.3Vout