LTC3555 Linear Technology, LTC3555 Datasheet - Page 9

• Manufacturer Part Number: LTC3555
• Description: High Efficiency USB Power Manager + Triple Step-Down DC/DC
• Manufacturer: Linear Technology

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TYPICAL PERFORMANCE CHARACTERISTICS
100
325
300
250
225
200
275
1.0
0.8
0.4
0.2
0.6
80
40
20
60
0
0
–40
–40
0
R
Power Switches vs Temperature
Switching Regulators 1, 2 Pulse
Skip Mode Quiescent Currents
⎯ R ⎯ S ⎯ T ⎯ 3 , ⎯ C ⎯ H ⎯ R ⎯ G Pin Current vs
Voltage (Pull-Down State)
V
BAT = 3.8V
V
DS(ON)
BUS
IN1,2
NMOS SWITCH
PMOS SWITCH
NMOS SWITCH
PMOS SWITCH
= 5V
–15
–15
= 3.8V
(CONSTANT FREQUENCY)
1
for Switching Regulator
CHRG PIN VOLTAGE (V)
TEMPERATURE (°C)
TEMPERATURE (°C)
10
10
2
V
OUT1,2
REGULATORS 1, 2
REGULATOR 3
V
(PULSE SKIPPING)
35
= 2.5V
35
OUT1,2
3
= 1.25V
60
60
4
3555 G22
3555 G25
3555 G19
85
85
5
1.95
1.90
1.80
1.75
1.70
1.85
AC COUPLED
20mV/DIV
5mA/DIV
V
I
LDO3V3
LDO3V3
2.0
1.5
1.0
0.5
0mA
0
–40
400
350
300
250
200
Switching Regulator Current Limit
vs Temperature
V
–40
IN1,2,3
3.3V LDO Step Response
(5mA to 15mA)
BAT = 3.8V
Switching Regulator 3 Pulse Skip
Mode Quiescent Currents
V
OUT3
–15
= 3.8V
–15
= 2.5V
TEMPERATURE (°C)
REGULATORS 1, 2
(CONSTANT FREQUENCY)
REGULATOR 3
10
TEMPERATURE (°C)
10
20μs/DIV
35
V
IN3
35
= 3.5V
60
V
(PULSE
SKIPPING)
IN3
60
3555 G23
= 3.8V
3555 G20
85
3555 G26
85
11
10
9
8
7
50
40
20
10
50
40
20
10
30
30
0
0
–40
–40
Battery Drain Current vs
Temperature
Switching Regulator Low Power
Mode Quiescent Currents
BAT = 3.8V
V
BUCK REGULATORS OFF
V
V
Switching Regulator Soft-Start
Waveform
BUS
IN1,2,3
OUT1,2,3
= 0V
–15
–15
OPERATION
Burst Mode
= 3.8V
FORCED
= 2.5V
TEMPERATURE (°C)
TEMPERATURE (°C)
10
10
50μs/DIV
LTC3555
35
35
OPERATION
Burst Mode
LDO MODE
60
60
3555 G24
3555 G21
9
3555 G27
3555f
85
85