Datasheet

LTC3890-3
5
38903f
For more information www.linear.com/3890-3
Typical perForMance characTerisTics
Efficiency and Power Loss
vs Output Current
Efficiency vs Output Current
Load Step
Burst Mode Operation
Load Step
Forced Continuous Mode
Load Step
Pulse-Skipping Mode
Inductor Current at Light Load
Soft Start-Up Tracking Start-Up
Efficiency vs Input Voltage
V
IN
= 12V
V
OUT
= 3.3V
FIGURE 13 CIRCUIT
50µs/DIV
38903 G04
V
OUT
100mV/DIV
AC-
COUPLED
I
L
2A/DIV
V
IN
= 12V
V
OUT
= 3.3V
FIGURE 13 CIRCUIT
50µs/DIV
38903 G05
V
OUT
100mV/DIV
AC-
COUPLED
I
L
2A/DIV
V
IN
= 12V
V
OUT
= 3.3V
FIGURE 13 CIRCUIT
50µs/DIV
38903 G06
V
OUT
100mV/DIV
AC-
COUPLED
I
L
2A/DIV
V
IN
= 12V
V
OUT
= 3.3V
I
LOAD
= 200µA
5µs/DIV
38903 G07
FORCED
CONTINUOUS
MODE
PULSE-SKIPPING
MODE
Burst Mode
OPERATION
1A/DIV
FIGURE 13 CIRCUIT
2ms/DIV
38903 G08
V
OUT2
2V/DIV
V
OUT1
2V/DIV
FIGURE 13 CIRCUIT
2ms/DIV
38903 G09
V
OUT2
2V/DIV
V
OUT1
2V/DIV
OUTPUT CURRENT (A)
0
EFFICIENCY (%)
70
100
10.10.010.0010.0001 10
38903 G02
50
40
30
20
10
60
80
90
V
OUT
= 8.5V
V
OUT
= 3.3V
V
IN
= 12V
Burst Mode OPERATION
FIGURE 13 CIRCUIT
INPUT VOLTAGE (V)
80
EFFICIENCY (%)
94
100
20 30 35 40 45 50 55 60151050 25
38903 G03
90
88
86
84
82
92
96
98
V
OUT1
= 3.3V
V
OUT2
= 8.5V
I
LOAD
= 2A
FIGURE 13 CIRCUIT
OUTPUT CURRENT (A)
FIGURE 13 CIRCUIT
0
EFFICIENCY (%)
POWER LOSS (mW)
70
100
10.10.010.0010.0001 10
38903 G01
50
40
30
20 1
10
100
1000
10000
0.1
10
60
80
90
V
IN
= 12V
V
OUT
= 3.3V
BURST EFFICIENCY
FCM LOSS
PULSE-SKIPPING
LOSS
BURST LOSS
FCM EFFICIENCY
PULSE-SKIPPING
EFFICIENCY