LTC3554 Datasheet, PDF (8/36 Pages) Linear Technology – Micropower USB Power Manager with Li-Ion Charger and Two Step-Down Regulators

LTC3554
TYPICAL PERFORMANCE CHARACTERISTICS T_A = 25°C, unless otherwise specified.
Switching from 100mA Mode to
500mA Mode
Switching from Suspend Mode to
500mA Mode
5V
HPWR
0
I_BUS
0.5A/DIV
0A
I_BAT
0.5A/DIV
0A
V_BAT = 3.75V
I_OUT = 50mA
R_PROG = 2k
1ms/DIV
5V
HPWR
0
5V
HPWR
0
I_BUS
0.5A/DIV
0A
I_BAT
0.5A/DIV
0A
3554 G14
V_BAT = 3.75V
I_OUT = 50mA
R_PROG = 2k
1ms/DIV
3554 G15
Step-Down Switching Regulator 1
3.3V Output Efficiency vs I_OUT1
100
FSEL = L
90
2.5V Output Efficiency
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
80
70
Burst Mode^® BV_IN Supply
Current Per Enabled Step-Down
Switching Regulator
35
NO LOAD
30
–45°C
25°C
90°C
25
60
20
50
40
15
30
20
10
0
0.01 0.1
1
10
I_OUT2 (mA)
3.8V
5V
100 1000
3554 G25
10
5
0
2.5
Burst Mode is a registered trademark of Linear Technology Corporation.
3 3.5 4 4.5 5 5.5
BV_IN SUPPLY VOLTAGE (V)
3554 G17
8
Oscillator Frequency
vs Temperature
2.6
2.7V
2.5
3.8V
5.5V
2.4
2.3
2.2
2.1
2.0
1.9
–75 –50 –25 0 25 50 75 100 125 150
TEMPERATURE (°C)
3554 G16
1.8V Output Efficiency
Standby Mode BV_IN Supply
Current Per Enabled Step-Down
Switching Regulator
3.0
NO LOAD
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
3554p