LTC3550-1_15 Datasheet, PDF (8/24 Pages) Linear Technology – Dual Input USB/AC Adapter Li-Ion Battery Charger with 600mA Buck Converter

LTC3550-1
TYPICAL PERFOR A CE CHARACTERISTICS T_A = 25°C, unless otherwise noted.
Buck Regulator Output Voltage
vs Load Current
1.90
V_CC = 3.6V
1.89
1.88
1.87
1.86
1.85
0
100 200 300 400 500 600 700 800 900
I_LOAD (mA)
35501 G28
Buck Regulator Supply
Current vs V_CC
50
45
V_OUT = 1.875V
I_LOAD = 0A
40
35
30
25
20
15
10
5
0
2
3
4
5
6
V_CC (V)
3550-1 G31
R_DS(ON) vs V_CC
0.7
T_A = 25°C
0.6
0.5
MAIN
SWITCH
0.4
0.3
SYNCHRONOUS
SWITCH
0.2
0.1
0
0 12 3 45
V_CC (V)
67
3550-1 G29
Buck Regulator Supply Current
vs Temperature
50
V_CC = 3.6V
45 _{VOUT = 1.875V}
40 ^{ILOAD = 0A}
35
30
25
20
15
10
5
0
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3550-1 G32
Buck Regulator Switches R_DS(ON)
vs Temperature
0.7
V_CC = 2.7V
0.6
V_CC = 4.2V ^{VCC = 3.6V}
0.5
0.4
0.3
0.2
0.1
0
–50
MAIN SWITCH
SYNCHRONOUS SWITCH
–25 0 25 50 75
TEMPERATURE (°C)
100 125
3550-1 G30
Switch Leakage Current
vs Temperature
300
V_CC = 5.5V
RUN = 0V
250
200
150
100
MAIN SWITCH
50
SYNCHRONOUS SWITCH
0
–50 –25
0 25 50 75 100 125
TEMPERATURE (°C)
3550-1 G33
8
Switch Leakage Current vs V_CC
120
RUN = 0V
100
SYNCHRONOUS
SWITCH
80
60
MAIN
SWITCH
40
20
0
0
1
2
3
4
V_CC (V)
56
3550-1 G34
Burst Mode Operation
SW
5V/DIV
V_OUT
20mV/DIV
I_L
200mA/DIV
V_CC = 3.6V
I_LOAD = 10mA
4µs/DIV
35501 G35
35501f