Performance Curves
Brick
Figure 15
10
µ
H
Half
48Vin 2.5Vout 60A
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)
3.00
2.75
Output Voltage
(V)
2.50
2.25
2.00
1.75
1.50
1.25
0.0
35V
48 V
75 V
12.5
25.0
37.5
Load Current
(A)
50.0
62.5
75.0
Figure 16:
Output voltage ripple at nominal input voltage and rated
load current (20 mV/div). Load capacitance: 1
µ
F ceramic capacitor
and 10
µ
F tantalum capacitor. Bandwidth: 20 MHz. (See Figure 13)
Figure 17:
Output voltage vs. load current showing typical current limit
curves and converter shutdown points.
Product # PQ48025HTA60
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.# 005-2HT425F Rev. Q
11/19/02
Page 7
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