LTC3421_15 Datasheet, PDF (4/16 Pages) Linear Technology – 3A, 3MHz Micropower Synchronous Boost Converter with Output Disconnect

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