Datasheet

LTC3880/LTC3880-1
10
3880fc
For more information www.linear.com/LTC3880
TYPICAL PERFORMANCE CHARACTERISTICS
Load Step
(Burst Mode Operation)
Load Step
(Forced Continuous Mode)
Load Step
(Pulse-Skipping Mode)
Efficiency vs Load Current,
V
OUT
= 1.8V (LTC3880)
Efficiency vs Load Current,
V
OUT
= 3.3V (LTC3880)
Efficiency and Power Loss
vs Input Voltage (LTC3880)
Inductor Current at Light Load Start-Up into a Pre-Biased Load Soft-Start Ramp
LOAD CURRENT (mA)
30
EFFICIENCY (%)
90
100
20
10
80
50
70
60
40
10 1000 10000 100000
3880 G01
0
100
CCM
DCM
BM
V
IN
= 12V
f
SW
= 364kHz
L = 0.56µH
DCR = 1.8m
LOAD CURRENT (mA)
30
EFFICIENCY (%)
90
100
20
10
80
50
70
60
40
10 1000 10000 100000
3880 G02
0
100
CCM
DCM
BM
V
IN
= 12V
f
SW
= 370kHz
L = 0.56µH
DCR = 1.8m
INPUT VOLTAGE (V)
5
88.0
EFFICIENCY (%)
POWER LOSS (mW)
88.5
89.0
89.5
90.0
90.5
91.0
1800
1900
2000
2100
2200
2300
2400
2500
7 9 11 13
3880 G03
15
V
OUT
= 1.8V
I
OUT
= 10A
I
LOAD
5A/DIV
INDUCTOR
CURRENT
5A/DIV
V
OUT
100mV/DIV
AC-COUPLED
50µs/DIVV
IN
= 12V
V
OUT
= 1.8V
0.3A TO 5A STEP
3880 G04
I
LOAD
5A/DIV
INDUCTOR
CURRENT
5A/DIV
V
OUT
100mV/DIV
AC-COUPLED
50µs/DIVV
IN
= 12V
V
OUT
= 1.8V
0.3A TO 5A STEP
3880 G05
I
LOAD
5A/DIV
INDUCTOR
CURRENT
5A/DIV
V
OUT
100mV/DIV
AC-COUPLED
50µs/DIVV
IN
= 12V
V
OUT
= 1.8V
0.3A TO 5A STEP
3880 G06
RUN
2V/DIV
V
OUT
1V/DIV
5ms/DIVt
RISE
= 10ms
t
DELAY
= 5ms
3880 G08
FORCED
CONTINUOUS
MODE
2A/DIV
Burst Mode
OPERATION
2A/DIV
PULSE-SKIPPING
MODE
2A/DIV
1µs/DIVV
IN
= 12V
V
OUT
= 1.8V
I
LOAD
= 100µA
3880 G07
RUN
2V/DIV
V
OUT
1V/DIV
5ms/DIVt
RISE
= 10ms
t
DELAY
= 5ms
3880 G09