LTC3554-1_15 Datasheet, PDF (9/36 Pages) Linear Technology – Micropower USB Power Manager with Li-Ion Charger and Two Step-Down Regulators

LTC3554/LTC3554-1/
LTC3554-2/LTC3554-3
Typical Performance Characteristics T_A = 25°C, unless otherwise specified.
Step-Down Switching Regulator 1
3.3V Output Efficiency vs I_OUT1
100
FSEL = L
90 STBY = L
80
70
60
50
40
30
20
10
0
0.01 0.1
1
10
I_OUT1 (mA)
3.8V
5V
100 1000
3554 G24a
Step-Down Switching Regulator 2
1.2V Output Efficiency vs I_OUT2
100
FSEL = L
90 STBY = L
80
70
60
50
40
30
20
10
0
0.01 0.1
1
10
I_OUT2 (mA)
3.8V
5V
100 1000
3554 G25
Step-Down Switching Regulator
Short-Circuit Current
vs Temperature
500
STBY = L
Step-Down Switching Regulator 1
2.5V Output Efficiency vs I_OUT1
100
FSEL = L
90 _{STBY = L}
80
70
60
50
40
30
20
10
0
0.01 0.1
1
10
I_OUT1 (mA)
3.8V
5V
100 1000
3554 G31
Burst Mode^® BV_IN Supply Current
Per Enabled Step-Down Switching
Regulator
35
NO LOAD
30 ^{STBY = L}
–45°C
25°C
90°C
25
20
15
10
5
0
2.5 3 3.5 4 4.5 5 5.5
BV_IN SUPPLY VOLTAGE (V)
3554 G17
Step-Down Switching Regulator
Output Transient
Step-Down Switching Regulator 2
1.8V Output Efficiency vs I_OUT2
100
FSEL = L
90 _{STBY = L}
80
70
60
50
40
30
20
10
0
0.01 0.1
1
10
I_OUT2 (mA)
3.8V
5V
100 1000
3554 G32
Standby Mode BV_IN Supply
Current Per Enabled Step-Down
Switching Regulator
3.0
NO LOAD
STBY = H
2.5
–45°C
25°C
90°C
2.0
1.5
1.0
0.5
0
2.5 3 3.5 4 4.5 5 5.5
BV_IN SUPPLY VOLTAGE (V)
3554 G18
Step-Down Switching Regulator
Output Transient
480
V_OUT2
V_OUT1
20mV/DIV
100mV/DIV
(AC)
(AC)
460
440
5mA
I_OUT2
10µA
420
400
–75 –50 –25 0 25 50 75 100 125 150
TEMPERATURE (°C)
3554 G19
V_OUT2 = 1.2V
STBY = H
50µs/DIV
150mA
I_OUT1
5mA
3554 G26
V_OUT1 = 3.3V
STBY = L
200µs/DIV
3554 G27
3554123ff
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