Datasheet

LTC3856
6
3856f
LOAD CURRENT (A)
0.1
40
EFFICIENCY (%)
50
60
70
80
1 10 100
30
20
10
0
90
100
3856 G03
V
IN
= 12V
V
OUT
= 1.5V
Burst Mode
OPERATION
FORCED
CONTINUOUS
MODE
Stage
Shedding
MODE
100µs/DIV
I
LOAD
40A/DIV
I
L1
20A/DIV
I
L2
20A/DIV
V
OUT
200mV/DIV
V
IN
= 12V
V
OUT
= 1.5V
I
LOAD
= 1A TO 40A
3856 G01
V
BAT
= 3.6V
I
CPO
= 200µA
C
CPO
= 2.2ΩF
100µs/DIV
I
LOAD
40A/DIV
I
L1
20A/DIV
I
L2
20A/DIV
V
OUT
200mV/DIV
V
IN
= 12V
V
OUT
= 1.5V
I
LOAD
= 1A TO 40A
3856 G02
V
BAT
= 3.6V
I
CPO
= 200µA
C
CPO
= 2.2ΩF
1µs/DIV
FORCED
CONTINUOUS
MODE, 5A/DIV
Burst Mode
OPERATION, 5A/DIV
DCM OPERATION,
5A/DIV
V
IN
= 12V
V
OUT
= 1.5V
I
LOAD
= 400mA
3856 G04
V
BAT
= 3.6V
I
CPO
= 200µA
C
CPO
= 2.2ΩF
Typical perForMance characTerisTics
Efficiency vs Output Current
and Mode Inductor Current at Light Load
Stage Shedding Transition,
1-Phase to 2-Phase
Stage Shedding Transition,
2-Phase to 1-Phase
Load Step:
Burst Mode Operation
Load Step:
Forced Continuous Mode
10µs/DIV
V
OUT
100mV/DIV
V
SW1
10V/DIV
V
SW2
10V/DIV
3856 G05
V
IN
= 12V
V
OUT
= 1.5V
UNDERSHOOT
35mV
10µs/DIV
V
OUT
100mV/DIV
V
SW1
10V/DIV
V
SW2
10V/DIV
3856 G06
V
IN
= 12V
V
OUT
= 1.5V
OVERSHOOT
36mV