Datasheet

LTC3554/LTC3554-1/
LTC3554-2/LTC3554-3
9
3554123fd
TYPICAL PERFORMANCE CHARACTERISTICS
Burst Mode
®
BV
IN
Supply Current
Per Enabled Step-Down Switching
Regulator
Standby Mode BV
IN
Supply
Current Per Enabled Step-Down
Switching Regulator
Step-Down Switching Regulator 1
3.3V Output Efficiency vs I
OUT1
Step-Down Switching Regulator 2
1.8V Output Efficiency vs I
OUT2
T
A
= 25°C, unless otherwise specified.
Step-Down Switching Regulator 1
2.5V Output Efficiency vs I
OUT1
Step-Down Switching Regulator 2
1.2V Output Efficiency vs I
OUT2
I
OUT1
(mA)
0.01 0.1
0
EFFICIENCY (%)
70
100
1 10 100 1000
3554 G24a
60
50
40
30
20
10
80
90
FSEL = L
STBY = L
3.8V
5V
I
OUT2
(mA)
0.01 0.1
0
EFFICIENCY (%)
70
100
1 10 100 1000
3554 G25
60
50
40
30
20
10
80
90
FSEL = L
STBY = L
3.8V
5V
BV
IN
SUPPLY VOLTAGE (V)
2.5 3 4 4.5 5.553.5
0
BV
IN
SUPPLY CURRENT (µA)
10
15
25
35
30
20
3554 G17
5
NO LOAD
STBY = L
–45°C
25°C
90°C
BV
IN
SUPPLY VOLTAGE (V)
2.5 3 4 4.5 5.553.5
0
BV
IN
SUPPLY CURRENT (µA)
1.0
1.5
2.5
3.0
2.0
3554 G18
0.5
NO LOAD
STBY = H
–45°C
25°C
90°C
I
OUT1
(mA)
EFFICIENCY (%)
3554 G31
0.01 0.1 100 1000101
0
20
30
80
40
50
60
90
100
70
10
FSEL = L
STBY = L
3.8V
5V
I
OUT2
(mA)
EFFICIENCY (%)
3554 G32
0.01 0.1 100 1000101
0
20
30
80
40
50
60
90
100
70
10
FSEL = L
STBY = L
3.8V
5V
Step-Down Switching Regulator
Output Transient
Step-Down Switching Regulator
Short-Circuit Current
vs Temperature
TEMPERATURE (°C)
–75 –50 –25 25 50 75 100 1501250
400
SHORT CIRCUIT CURRENT (mA)
440
460
500
480
3554 G19
420
STBY = L
V
OUT2
= 1.2V
STBY = H
V
OUT2
20mV/DIV
(AC)
5mA
10µA
I
OUT2
3554 G26
50µs/DIV
Step-Down Switching Regulator
Output Transient
V
OUT1
= 3.3V
STBY = L
V
OUT1
100mV/DIV
(AC)
150mA
5mA
I
OUT1
3554 G27
200µs/DIV