Datasheet

LTC3421
4
3421f
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Single Cell to 3.3V Efficiency
OUTPUT CURRENT (mA)
30
EFFICIENCY (%)
90
100
20
10
80
50
70
60
40
0.1 10 100 1000
3421 G01
0
1
Burst Mode OPERATION
V
IN
= 1.5V
V
OUT
= 3.3V
f
OSC
= 1MHz
V
IN
= 1V
V
IN
= 1.2V
OUTPUT CURRENT (mA)
30
EFFICIENCY (%)
90
100
20
10
80
50
70
60
40
0.1 10 100 1000
3421 G02
0
1
Burst Mode OPERATION
V
IN
= 3V
V
OUT
= 3.3V
f
OSC
= 1MHz
V
IN
= 2.4V
V
IN
= 2V
OUTPUT CURRENT (mA)
30
EFFICIENCY (%)
90
100
20
10
80
50
70
60
40
0.1 10 100 1000
3421 G03
0
1
Burst Mode
OPERATION
V
OUT
= 5V
f
OSC
= 1MHz
V
IN
= 4.2V
V
IN
= 3.6V
V
IN
= 2.7V
2-Cell to 3.3V Efficiency Li-Ion to 5V Efficiency
Burst Mode Operation Load Transient Response Inrush Current Control
Efficiency vs Frequency Efficiency vs V
IN
Start-Up Voltage vs Output Current
OUTPUT CURRENT (mA)
1
40
EFFICIENCY (%)
50
60
70
80
10 100 1000
3421 G07
30
20
10
0
90
100
V
IN
= 2.4V
V
OUT
= 3.3V
f = 300kHz
f = 3MHz
f = 1MHz
INPUT VOLTAGE (V)
1
0
EFFICIENCY (%)
10
30
40
50
100
70
2
3
3.5
3421 G08
20
80
90
60
1.5 2.5
4
4.5
5
V
IN
> V
OUT
PMOS LDO MODE
V
OUT
= 3.3V
I
OUT
= 200mA
OUTPUT CURRENT (mA)
0
START VOLTAGE (V)
1.00
1.05
1.10
200
3421 G09
0.95
0.90
0.80
50
100
150
0.85
1.20
1.15
V
OUT
50mV/DIV
AC COUPLED
INDUCTOR
CURRENT
0.5A/DIV
SW
2.5µs/DIV
3421 G04
V
OUT
100mV/DIV
AC COUPLED
600mA
V
IN
= 2.4V 2.5ms/DIV 3421 G05
V
OUT
= 3.3V
C
OUT
= 44µF
50mA
I
OUT
V
OUT
1V/DIV
INDUCTOR
CURRENT
0.5A/DIV
V
IN
= 0V TO 2.4V 500µs/DIV 3421 G06
C
OUT
= 44µF
(T
A
= 25°C, unless otherwise specified)