4
AN1482.0
June 30, 2009
.
FIGURE 4. LOAD TRANSIENT CIRCUIT FOR PWM1
OPT. LOAD TRAN.
R26
OPT
M8
OPT
R27
OPT
Typical Evaluation Board Performance Curves
V
IN
= 12V, Unless Otherwise Noted.
FIGURE 5. PWM1 EFFICIENCY vs LOAD (V
O
= 1.0V)
FIGURE 6. PWM2 EFFICIENCY vs LOAD (V
O
= 3.3V)
FIGURE 7. PWM3 EFFICIENCY vs LOAD (V
O
= 5.0V)
FIGURE 8. PWM1 OUTPUT RIPPLE UNDER MAX LOAD
(V
IN
= 12V, I
O1
= I
O2
= 6A, I
O3
= 4A, FULL
BANDWIDTH)
E
F
FICIE
NCY (
%
)
LOAD CURRENT (A)
40
45
50
55
60
65
70
75
80
85
90
0
8
V
IN
= 9VDC
V
IN
= 12VDC
1
2
3
4
5
6
7
V
IN
= 16VDC
EFFICIENCY (%)
50
55
60
65
70
75
80
85
90
95
100
LOAD CURRENT (A)
0
8
1
2
3
4
5
6
7
V
IN
= 16VDC
V
IN
= 12VDC
V
IN
= 9VDC
LOAD CURRENT (A)
EF
FIC
IEN
C
Y
(%
)
50
55
60
65
70
75
80
85
90
95
100
0
2
4
6
5
3
1
V
IN
= 16VDC
V
IN
= 12VDC
V
IN
= 9VDC
V
OUT1
(AC), 10mV/DIV
500n
s
/DIV
Application Note 1482
