Linear Technology LTC3558, Manual

Page: 9 / 32

LTC3558
9
3558f
Buck Regulator Start-Up Transient
Buck Regulator
Pulse Skip Mode Operation
V
OUT
500mV/DIV
EN
2V/DIV
PV
IN1
= 3.8V
PULSE SKIP MODE
LOAD = 6Ω
50μs/DIV
3558 G28
INDUCTOR
CURRENT
I
L
= 200mA/
DIV
Buck Regulator
Burst Mode Operation
V
OUT
20mV/
DIV (AC)
SW
2V/DIV
PV
IN1
= 3.8V
LOAD = 10mA
200ns/DIV
3558 G29
INDUCTOR
CURRENT
I
L
= 50mA/
DIV
V
OUT
20mV/
DIV (AC)
SW
2V/DIV
PV
IN1
= 3.8V
LOAD = 60mA
2μs/DIV
3558 G30
INDUCTOR
CURRENT
I
L
= 60mA/
DIV
TYPICAL PERFORMANCE CHARACTERISTICS
Buck Regulator Transient
Response, Pulse Skip Mode
V
OUT
50mV/
DIV (AC)
LOAD STEP
5mA TO
290mA
PV
IN1
= 3.8V 50μs/DIV
3558 G31
INDUCTOR
CURRENT
I
L
= 200mA/
DIV
Buck Regulator Transient
Response, Burst Mode Operation
V
OUT
50mV/
DIV (AC)
LOAD STEP
5mA TO
290mA
PV
IN1
= 3.8V 50μs/DIV
3558 G32
INDUCTOR
CURRENT
I
L
= 200mA/
DIV
Buck-Boost Regulator Input
Current vs Temperature
Buck-Boost Regulator Input
Current vs Temperature Buck-Boost Regulator PMOS
R
DS(ON)
vs Temperature
Buck-Boost Regulator NMOS
R
DS(ON)
vs Temperature
TEMPERATURE (°C)
–55
5
INPUT CURRENT (μA)
10
20
25
30
–15 25 45 125
3558 G33
15
–35 5 65 85 105
Burst Mode OPERATION
FB2 = 0.85V
PV
IN2
= 2.7V
PV
IN2
= 4.2V
TEMPERATURE (°C)
–55
100
INPUT CURRENT (μA)
150
250
300
350
500
450
–15 25 45 125
3558 G34
200
400
–35 5 65 85 105
PV
IN2
= 2.7V
PV
IN2
= 4.2V
PWM MODE
FB2 = 0.85V
–55 –15 25 45 125 –35 5 65 85 105
TEMPERATURE (°C)
R
DS(ON)
(mΩ)
400
650
700
750
800
300
550
350
600
250
200
500
450
3558 G35
PV
IN2
= 2.7V
PV
IN2
= 4.2V
TEMPERATURE (°C)
–55
200
R
DS(ON)
(mΩ)
300
500
600
700
1200
900
–15 25 45 125
3558 G36
400
1000
1100
800
–35 5 65 85 105
PV
IN2
= 2.7V
PV
IN2
= 4.2V
T
A
= 25°C, unless otherwise noted.