UG067 Rev.2.00
Page 12 of 22
Aug 23, 2017
ISL68200DEMO1Z
FIGURE 13. EFFICIENCY, V
IN
= 12V, f
SW
= 600kHz
FIGURE 14. EFFICIENCY, V
IN
= 5V, f
SW
= 600kHz
FIGURE 15. EFFICIENCY COMPARISON OF PWM MODE AND PFM
ENABLED MODE, V
IN
= 12V, V
OUT
= 1V
FIGURE 16. EFFICIENCY COMPARISON OF PWM MODE AND PFM
ENABLED MODE, V
IN
= 5V, V
OUT
= 1V
FIGURE 17. EFFICIENCY COMPARISON OF LDO ENABLED AND
BYPASSED, V
IN
= 5V, V
OUT
= 1V, f
SW
= 500kHz
FIGURE 18. POWER-UP WITH/WITHOUT PRECHARGE AT 1A LOAD
Measured Data
The following data was acquired using a ISL68200DEMO1Z board. (Continued)
80
81
82
83
84
85
86
87
88
89
90
91
92
0
2
4
6
8
10
12
14
16
18
20
22
24
LOAD CURRENT (A)
VOUT=0.8V
VOUT=1V
VOUT=1.2V
VOUT=1.5V
VOUT=1.8V
EFFICIENCY (%
)
83
84
85
86
87
88
89
90
91
92
93
94
95
0
2
4
6
8
10
12
14
16
18
20
22
24
LOAD CURRENT (A)
VOUT=0.8V
VOUT=1V
VOUT=1.2V
VOUT=1.5V
VOUT=1.8V
EFFICIE
N
CY
(%)
-5
0
5
10
15
20
25
30
75
77.5
80
82.5
85
87.5
90
0
2
4
6
8
10 12 14 16 18 20 22 24
LOAD CURRENT (A)
PWM at Fsw=400kHz
PFM EN at Fsw=400kHz
PWM at Fsw=500kHz
PFM EN at Fsw=500kHz
PWM at Fsw=600kHz
PFM EN at Fsw=600kHz
EFFICIE
N
CY
(%)
EFFI
CIENCY
BOO
ST
B
Y P
F
M EN
(%
)
-5
0
5
10
15
20
25
80
82
84
86
88
90
92
94
0
2
4
6
8
10 12 14 16 18 20 22 24
LOAD CURRENT (A)
PWM at Fsw=400kHz
PFM EN at Fsw=400kHz
PWM at Fsw=500kHz
PFM EN at Fsw=500kHz
PWM at Fsw=600kHz
PFM EN at Fsw=600kHz
E
F
F
ICIENCY (%
)
EFFI
CIE
N
C
Y
BO
O
ST
B
Y
PFM E
N
(%
)
83
84
85
86
87
88
89
90
91
92
93
0
2
4
6
8
10
12
14
16
18
20
22
24
LOAD CURRENT (A)
ALL RAILS TIED TOGETHER
LDO ENABLED
EFFICIE
N
CY
(%)
EN
PGOOD
PRECHARGED V
OUT
< 1V
PGOOD AT 1.14V, PRECHARGED V
OUT
1.14V PRECHARGED VOUT
0.8V PRECHARGED VOUT
0.3V PRECHARGED VOUT
VOUT WITHOUT PRECHARGE
200µs/DIV
