Datasheet

LTC3883/LTC3883-1
9
3883fa
For more information www.linear.com/LTC3883
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 (LTC3883)
Efficiency vs Load Current,
V
OUT
= 3.3V (LTC3883)
Efficiency and Power Loss
vs Input Voltage (LTC3883)
Inductor Current at Light Load Start-Up into a Pre-Biased Load Soft-Start Ramp
LOAD CURRENT (A)
30
EFFICIENCY (%)
90
100
20
10
80
50
70
60
40
0.01 1 10 100
3883 G01
0
0.1
CCM
DCM
BM
V
IN
= 12V
V
OUT
= 1.8V
f
SW
= 350kHz
L = 0.56µH
DCR = 1.8mΩ
V
IN
(V)
5
80
EFFICIENCY (%)
POWER LOSS (W)
82
84
86
88
90
92
1.0
1.5
2.0
2.5
3.0
3.5
4.0
10 15 20
3883 G03
25
RUN
2V/DIV
V
OUT
1V/DIV
5ms/DIVt
RISE
= 10ms
t
DELAY
= 5ms
V
OUT
= 2V
3883 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
3883 G07
RUN
2V/DIV
V
OUT
1V/DIV
5ms/DIVt
RISE
= 10ms
t
DELAY
= 5ms
3883 G09
LOAD CURRENT (A)
30
EFFICIENCY (%)
90
100
20
10
80
50
70
60
40
0.01 1 10 100
3883 G02
0
0.1
CCM
DCM
BM
V
IN
= 12V
V
OUT
= 3.3V
f
SW
= 350kHz
L = 0.56µH
DCR = 1.8mΩ
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
3883 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
3883 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
3883 G06
ELECTRICAL CHARACTERISTICS
less than the minimum endurance specification. The RESTORE_USER_ALL
command (NVM read) is valid over the entire operating temperature range.
Note 14: The LTC3883-1 quiescent current (I
Q
) equals the I
Q
of V
IN
plus
the I
Q
of EXTV
CC
.
Note 15: The LTC3883 includes overtemperature protection that is
intended to protect the device during momentary overload conditions.
Junction temperature will exceed 125°C when overtemperature protection
is active. Continuous operation above the specified maximum operating
junction temperature may impair device reliability.