Datasheet

LTC3553
11
3553fb
TYPICAL PERFORMANCE CHARACTERISTICS
T
A
= 25°C, unless otherwise specifi ed.
LDO Dropout Voltage at
V
INLDO
= 3.8V
LDO LOAD (mA)
25 50 75 100 1501250
0
LDO DROPOUT VOLTAGE (mV)
100
150
200
250
300
3553 G37
50
–45°C
25°C
90°C
LDO Dropout Voltage at
V
INLDO
= 2.5V
LDO LOAD (mA)
25 50 75 100 1501250
0
LDO DROPOUT VOLTAGE (mV)
100
150
200
250
300
3553 G38
50
–45°C
25°C
90°C
LDO LOAD (mA)
15 30 45 60 750
0
LDO DROPOUT VOLTAGE (mV)
100
150
200
250
300
3553 G39
50
–45°C
25°C
90°C
LDO Dropout Voltage at
V
INLDO
= 1.8V
V
BUS
= 0V
V
BAT
= 3.8V
STBY = LOW
V
OUT
50mV/DIV
(AC)
LDO (3.3V)
50mV/DIV
(AC)
100mA
1mA
I
LDO
3553 G40
50µs/DIV
V
BUS
= 0V
V
BAT
= 3.8V
STBY = HIGH
V
OUT
50mV/DIV
(AC)
LDO (3.3V)
100mV/DIV
(AC)
100mA
1mA
I
LDO
3553 G41
50µs/DIV
BUCK OUTPUT CONNECTED TO V
INLDO
5mA LDO LOAD
4.7µF LDO OUTPUT CAPACITOR
V
BAT
= 3.8V, V
BUS
= 0V
BUCK OUTPUT
1.8V
10mV/DIV (AC)
LDO OUTPUT
1.2V
10mV/DIV (AC)
3553 G42
10µs/DIV
LDO Output Transient
(STBY = Low)
LDO Output Transient
(STBY = High)
LDO Rejection of Buck
Output Ripple