Datasheet

LTC3869/LTC3869-2
5
38692fa
For more information www.linear.com/LTC3869
Efficiency vs Output Current
and Mode
Efficiency vs Output Current
and Mode
Full Load Efficiency and Power
Loss vs Input Voltage
LOAD CURRENT (A)
0.01
EFFICIENCY (%)
100
10
90
70
50
30
80
60
40
20
0
10
3869 G01
10010.1
V
IN
= 12V
V
OUT
= 1.8V
Burst Mode
OPERATION
DCM
CCM
CIRCUIT OF FIGURE 16
LOAD CURRENT (A)
0.01
EFFICIENCY (%)
100
10
90
70
50
30
80
60
40
20
0
10
3869 G02
10010.1
V
IN
= 12V
V
OUT
= 1.2V
Burst Mode
OPERATION
DCM
CCM
CIRCUIT OF FIGURE 16
INPUT VOLTAGE (V)
5
75
EFFICIENCY (%)
80
85
90
2
POWER LOSS (W)
3
4
5
10 2015
3869 G03
1.8V
1.8V
1.2V
1.2V
EFFICIENCY
POWER LOSS
CIRCUIT OF FIGURE 16
Typical perForMance characTerisTics
Load Step
(Burst Mode Operation)
Load Step
(Forced Continuous Mode)
Load Step
(Pulse-Skipping Mode)
Inductor Current at Light Load
Prebiased Output at 2V
T
A
= 25°C, unless otherwise noted.
V
IN
= 12V
V
OUT
= 1.8V
I
LOAD
= 400mA
1µs/DIV
3869 G07
FORCED
CONTINUOUS
MODE
5A/DIV
Burst Mode
OPERATION
5A/DIV
PULSE-
SKIPPING
MODE
5A/DIV
V
IN
= 12V
V
OUT
= 3.3V
2ms/DIV
3869 G08
TK/SS
500mV/DIV
V
FB
500mV/DIV
V
OUT
2V/DIV
V
IN
= 12V
V
OUT
= 1.8V
50µs/DIV
3869 G04
I
L
5A/DIV
V
OUT
100mV/DIV
AC-COUPLED
I
LOAD
5A/DIV
300mA TO 5A
V
IN
= 12V
V
OUT
= 1.8V
50µs/DIV
3869 G05
I
L
5A/DIV
V
OUT
100mV/DIV
AC-COUPLED
I
LOAD
5A/DIV
300mA TO 5A
V
IN
= 12V
V
OUT
= 1.8V
50µs/DIV
3869 G06
I
L
5A/DIV
V
OUT
100mV/DIV
AC-COUPLED
I
LOAD
5A/DIV
300mA TO 5A