Datasheet

3
LTC3405A-1.5/LTC3405A-1.8
3405a1518fa
INPUT VOLTAGE (V)
2.5 3.0 4.0 5.0
EFFICIENCY (%)
4.5
95
90
85
80
75
70
65
60
55
50
3405A1518 G02
3.5 5.5
Burst Mode OPERATION
V
OUT
= 1.8V
I
OUT
= 0.1mA
I
OUT
= 250mA
I
OUT
= 100mA
I
OUT
= 10mA
I
OUT
= 1mA
OUTPUT CURRENT (mA)
0.1
EFFICIENCY (%)
10
1000
100
90
80
70
60
50
40
30
20
10
0
3405A1518 G03
1 100
V
IN
= 3.6V
V
IN
= 4.2V
V
IN
= 3.6V
V
IN
= 4.2V
V
OUT
= 1.8V
PULSE SKIPPING MODE
Burst Mode OPERATION
OUTPUT CURRENT (mA)
0.1
EFFICIENCY (%)
10
1000
100
90
80
70
60
50
40
3405A1518 G04
1 100
V
IN
= 2.7V
V
IN
= 5.5V
V
IN
= 4.2V
V
IN
= 3.6V
V
OUT
= 1.8V
TYPICAL PERFOR A CE CHARACTERISTICS
UW
OUTPUT CURRENT (mA)
60
EFFICIENCY (%)
80
100
50
70
90
0.1 10 100 1000
3405A1518 G05
40
1
V
IN
= 2.7V
V
IN
= 4.2V
V
OUT
= 1.5V
V
IN
= 3.6V
Efficiency vs Input Voltage
Efficiency vs Output Current
Efficiency vs Output Current
Efficiency vs Output Current
Oscillator Frequency vs
Temperature
Oscillator Frequency vs
Supply Voltage
Output Voltage vs Load Current
R
DS(ON
) vs Input Voltage
TEMPERATURE (°C)
–50
FREQUENCY (MHz)
1.70
1.65
1.60
1.55
1.50
1.45
1.40
1.35
1.30
25 75
–25 0
50 100 125
V
IN
= 3.6V
3405A1518 G07
SUPPLY VOLTAGE (V)
2
OSCILLATOR FREQUENCY (MHz)
1.8
1.7
1.6
1.5
1.4
1.3
1.2
34 56
3405A1518 G08
LOAD CURRENT (mA)
0
OUTPUT VOLTAGE (V)
1.834
1.824
1.814
1.804
1.794
1.784
1.774
100
200 300 400
3405A1518 G09
500 600
Burst Mode
OPERATION
PULSE SKIPPING MODE
INPUT VOLTAGE (V)
0
R
DS(0N)
(Ω)
2
4
5
3405A1518 G10
13
6
7
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
MAIN SWITCH
SYNCHRONOUS
SWITCH
(From Figure1a)
R
DS(ON)
vs Temperature
TEMPERATURE (°C)
–50
R
DS(ON)
(Ω)
1.2
1.0
0.8
0.6
0.4
0.2
0
25 75
–25 0
50 100 125
3405F G11
SYNCHRONOUS SWITCH
MAIN SWITCH
V
IN
= 2.7V
V
IN
= 3.6V
V
IN
= 4.2V