LTC3558_15 Datasheet, PDF (9/32 Pages) Linear Technology – Linear USB Battery Charger with Buck and Buck-Boost Regulators

LTC3558
TYPICAL PERFORMANCE CHARACTERISTICS T_A = 25°C, unless otherwise noted.
Buck Regulator Start-Up Transient
Buck Regulator
Pulse Skip Mode Operation
Buck Regulator
Burst Mode Operation
V_OUT
500mV/DIV
INDUCTOR
CURRENT
I_L = 200mA/
DIV
EN
2V/DIV
PV_IN1 = 3.8V
50μs/DIV
PULSE SKIP MODE
LOAD = 6Ω
V_OUT
20mV/
DIV (AC)
SW
2V/DIV
3558 G28
INDUCTOR
CURRENT
I_L = 50mA/
DIV
PV_IN1 = 3.8V
LOAD = 10mA
200ns/DIV
V_OUT
20mV/
DIV (AC)
SW
2V/DIV
3558 G29
INDUCTOR
CURRENT
I_L = 60mA/
DIV
PV_IN1 = 3.8V
LOAD = 60mA
2μs/DIV
3558 G30
Buck Regulator Transient
Response, Pulse Skip Mode
INDUCTOR
CURRENT
I_L = 200mA/
DIV
Buck Regulator Transient
Response, Burst Mode Operation
INDUCTOR
CURRENT
I_L = 200mA/
DIV
V_OUT
50mV/
DIV (AC)
LOAD STEP
5mA TO
290mA
PV_IN1 = 3.8V
50μs/DIV
V_OUT
50mV/
DIV (AC)
LOAD STEP
5mA TO
290mA
3558 G31
PV_IN1 = 3.8V
50μs/DIV
3558 G32
Buck-Boost Regulator Input
Current vs Temperature
500
PWM MODE
450 ^{FB2 = 0.85V}
400
350
300
PV_IN2 = 4.2V
250
200
PV_IN2 = 2.7V
150
100
–55 –35 –15 5 25 45 65 85 105 125
TEMPERATURE (°C)
3558 G34
Buck-Boost Regulator PMOS
R_DS(ON) vs Temperature
800
750
700
650
600
PV_IN2 = 2.7V
550
500
450
400
PV_IN2 = 4.2V
350
300
250
200
–55 –35 –15 5 25 45 65 85 105 125
TEMPERATURE (°C)
3558 G35
Buck-Boost Regulator Input
Current vs Temperature
30
Burst Mode OPERATION
FB2 = 0.85V
25
PV_IN2 = 4.2V
20
PV_IN2 = 2.7V
15
10
5
–55 –35 –15 5 25 45 65 85 105 125
TEMPERATURE (°C)
3558 G33
Buck-Boost Regulator NMOS
R_DS(ON) vs Temperature
1200
1100
1000
900
800
PV_IN2 = 2.7V
700
600
500
PV_IN2 = 4.2V
400
300
200
–55 –35 –15 5 25 45 65 85 105 125
TEMPERATURE (°C)
3558 G36
3558f
9