L4978
Figure 24. Load transient.
.
Figure 27. Soft start capacitor selection Vs
inductor and V
ccmax
.
L
(µH)
D97IN746
fsw=200KHz
56nF
300
47nF
200
33nF
22nF
100
0
15 20 25 30 35 40 45 50 V
CC
max(V)
Figure 25. Line transient.
.
V
CC
(V)
30
20
D97IN786
Figure 28. Open loop frequency and phase of
error amplifier .
GAIN
(dB)
50
GAIN
D97IN787
Phase
0
10
1
I
O
= 1A
f
sw
= 100KHz
0
45
90
Phase
V
O
(mV)
100
0
-50
-100
-150
2
135
-100
1ms/DIV
-200
10
10
2
10
3
10
4
10
5
10
6
10
7
10
8
f(Hz)
Figure 26. Soft start capacitor selection Vs
inductor and V
ccmax
.
L
(µH)
fsw=100KHz
D97IN745
680nF
470nF
400
330nF
300
200
220nF
100
100nF
0
15 20 25 30 35 40 45 50 V
CCmax
(V)
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