LTC3557 LINER [Linear Technology], LTC3557 Datasheet - Page 8

• Manufacturer Part Number: LTC3557
• Description: USB Power Manager with Li-Ion Charger and Three Step-Down Regulators
• Manufacturer: LINER [Linear Technology]

LTC3557/LTC3557-1
TYPICAL PERFORMANCE CHARACTERISTICS
8
I
OUT2
50mV/DIV
50mV/DIV
100
2.5
2.4
2.3
2.2
2.1
2.0
1.9
1.8
1.7
1.6
1.5
20
10
90
80
70
60
50
40
30
300mA
0
0.01
V
V
–50
OUT2
OUT3
5mA
(AC)
(AC)
Oscillator Frequency
vs Temperature
Step-Down Switching Regulator 3
1.8V Output Effi ciency vs I
OPERATION
Burst Mode
–25
Step-Down Switching Regulator
Output Transient (MODE = 1)
V
V
I
OUT3
OUT2
OUT3
0.1
= 16mA
= 1.2V
= 1.8V
0
TEMPERATURE (°C)
V
1
I
OUT3
25
IN
= 2.9V
(mA)
50
50μs/DIV
10
PULSE SKIP
75
V
OUT3
V
V
V
V
V
100
IN3
IN3
OUT3
IN
IN
IN
100
= 3.8V
= 2.7V
= 3.8V
= 5V
= 5V
= 1.8V
35571 G16
35571 G13
1000
125
35571 G1
I
OUT2
50mV/DIV
50mV/DIV
400
350
300
250
200
150
100
100
20
10
90
80
70
60
50
40
30
300mA
0
0.01
V
V
2.5
OUT2
OUT3
(AC)
(AC)
5mA
Step-Down Switching Regulator 1
3.3V Output Effi ciency vs I
Step-Down Switching Regulator
Pulse Skip Supply Current vs V
OPERATION
Burst Mode
V
I
OUTX
OUTX
Step-Down Switching Regulator
Output Transient (MODE = 0)
V
V
I
OUT3
OUT2
OUT3
3.0
= 0mA
0.1
= 1.2V
= 100mA
= 1.2V
= 1.8V
3.5
1
I
OUT1
V
INX
(mA)
(V)
50μs/DIV
4.0
10
PULSE SKIP
V
OUT1
V
V
OUT1
100
4.5
IN1
IN1
= 3.8V
= 5V
= 3.3V
110°C
–45°C
75°C
25°C
35571 G17
35571 G14
T
INX
A
1000
= 25°C unless otherwise specifi ed
5.0
35571 G2
1200
1100
1000
0.5
0.4
0.2
100
900
800
700
600
500
400
0.9
0.8
0.7
0.6
0.3
0.1
90
80
70
60
50
40
30
20
10
0
0
0.01
–50
–50
Step-Down Switching Regulator 2
1.2V Output Effi ciency vs I
Step-Down Switching
Regulator Short-Circuit Current
vs Temperature
Step-Down Switching Regulator
Switch Impedance vs Temperature
V
400mA
INX
NMOS
OPERATION
Burst Mode
–25
–25
= 3.2V
0.1
0
0
TEMPERATURE (°C)
TEMPERATURE (°C)
400mA
600mA BUCK
400mA BUCK
PMOS
1
I
OUT2
25
25
PULSE SKIP
600mA NMOS
(mA)
50
50
10
75
600mA PMOS
75
V
OUT2
V
V
OUT2
100
IN2
IN2
100
100
= 3.8V
= 5V
= 1.2V
35571 G21
35571 G15
35571 G18
35571fc
1000
125
125