Performance Curves
Brick
Figure 15
10
µ
H
Half
48Vin 3.3Vout 50A
source
impedance
Figure 14
Figure 16
i
S
V
SOURCE
i
C
DC/DC
Converter
1
µ
F
V
OUT
15 µF,
47 µF,
<1Ω ESR
electrolytic
capacitor
ceramic
450mΩ ESR
capacitor
tantalum
capacitor
Figure 13:
Test set-up diagram showing measurement points for Input
Terminal Ripple Current (Figure 14), Input Reflected Ripple Current
(Figure 15) and Output Voltage Ripple (Figure 16).
Figure 14:
Input Terminal Ripple Current, ic, at full rated output cur-
rent and nominal input voltage with 10
µ
H source impedance and 47
µ
F
electrolytic capacitor (100 mA/div). (See Figure 13)
Figure 15:
Input reflected ripple current, is, through a 10
µ
H source
inductor at nominal input voltage and rated load current (5 mA/div).
(See Figure 13)
Figure 16:
Output voltage ripple at nominal input voltage and rated
load current (20 mV/div). Load capacitance: 1
µ
F ceramic capacitor
and 15
µ
F tantalum capacitor. Bandwidth: 20 MHz. (See Figure 13)
3.6
3.4
3.2
Output Voltage
(V)
3.0
2.8
2.6
2.4
2.2
2.0
1.8
1.6
1.4
0.0
35 V
48 V
75 V
10.0
20.0
30.0
40.0
50.0
60.0
70.0
Load Current
(A)
Figure 17:
Output voltage vs. load current showing typical current limit
curves and converter shutdown points.
Product # PQ60033HTA50
Phone 1-888-567-9596
Figure 18:
Load current (20A/div) as a function of time when the con-
verter attempts to turn on into a 1 mΩ short circuit. Top trace
(2ms/div) is an expansion of the on-time portion of the bottom trace.
Doc.# 005-2HT633F Rev. A
4/11/03
Page 7