Datasheet

LTC3865/LTC3865-1
6
3865fb
Load Step
(Burst Mode Operation)
Load Step
(Forced Continuous Mode)
Load Step
(Pulse-Skipping Mode)
Inductor Current at Light Load Prebiased Output at 1V
Coincident Tracking
V
OUT
100mV/DIV
AC-
COUPLED
I
LOAD
5A/DIV
500mA
TO 7A
I
L
5A/DIV
40µs/DIVV
IN
= 12V
V
OUT
= 1.5V
FIGURE 16 CIRCUIT
3865 G01
V
OUT
100mV/DIV
AC-
COUPLED
I
LOAD
5A/DIV
500mA
TO 7A
I
L
5A/DIV
40µs/DIV
3865 G02
V
IN
= 12V
V
OUT
= 1.5V
FIGURE 16 CIRCUIT
V
OUT
100mV/DIV
AC-
COUPLED
I
LOAD
5A/DIV
500mA
TO 7A
I
L
5A/DIV
40µs/DIV
3865 G03
V
IN
= 12V
V
OUT
= 1.5V
FIGURE 16 CIRCUIT
RUN
2V/DIV
V
TRACK/SS
1V/DIV
V
OUT
= 1.5V
500mV/DIV
40ms/DIV
3865 G05
FORCED
CONTINUOUS
MODE
5A/DIV
PULSE-
SKIPPING MODE
5A/DIV
Burst Mode
OPERATION
5A/DIV
2µs/DIVV
IN
= 12V
V
OUT
= 1.5V
I
LOAD
= 100mA
FIGURE 16 CIRCUIT
3865 G04
RUN1
2V/DIV
40ms/DIV
3865 G06
V
OUT2
= 1.2V
1 LOAD
500mV/DIV
V
OUT1
= 1.5V
1 LOAD
500mV/DIV
TYPICAL PERFORMANCE CHARACTERISTICS
Effi ciency vs Load Current Effi ciency vs Load Current
Effi ciency and Power Loss
vs Input Voltage
LOAD CURRENT (A)
30
EFFICIENCY (%)
90
100
20
10
80
50
70
60
40
0.01 1 10 100
3865 G23
0
0.1
V
IN
= 12V
V
OUT
= 1.5V
FIGURE 16 CIRCUIT
BURST
DCM CCM
LOAD CURRENT (A)
30
EFFICIENCY (%)
90
100
20
10
80
50
70
60
40
0.01 1 10 100
3865 G24
0
0.1
V
IN
= 12V
V
OUT
= 1.2V
FIGURE 16 CIRCUIT
BURST
DCM
CCM
INPUT VOLTAGE (V)
0
EFFICIENCY (%)
POWER LOSS (W)
50
60
70
3865 G25
40
30
20
10 20
80
90
100
3
2
1
0
4
5
30
EFFICIENCY
POWER LOSS
FIGURE 16 CIRCUIT