Datasheet

4
LTC1751/LTC1751-3.3/LTC1751-5
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Power Efficiency vs Load Current
Short-Circuit Output Current
vs Input Voltage
LOAD CURRENT (mA)
0.001
40
EFFICIENCY (%)
50
60
70
80
0.01 0.1 1 10 100
1751 G04
30
20
10
0
90
100
V
IN
= 2.75V
V
IN
= 2V
V
IN
= 4.4V
V
IN
= 3.3V
T
A
= 25°C
C
FLY
= 1µF
C
OUT
= 10µF
INPUT VOLTAGE (V)
2.0
OUTPUT CURRENT (mA)
150
200
4.0
1751 G05
100
50
2.5
3.0
3.5
4.5
250
T
A
= 25°C
C
FLY
= 1µF
Start-Up
C
SS
= 10nF 2ms/DIV 1751 G06
SHDN
2V/DIV
PGOOD
5V/DIV
V
OUT
1V/DIV
Output Ripple
V
IN
= 2.5V 5µs/DIV 1751 G07
I
OUT
= 80mA
C
OUT
= 10µF
V
OUT
AC COUPLED
50mV/DIV
Load Transient Response
V
IN
= 2.5V 50µs/DIV 1751 G08
V
OUT
AC COUPLED
50mV/DIV
I
OUT
40mA/DIV
(LTC1751-3.3)
(LTC1751-5)
OUTPUT CURRENT (mA)
0
OUTPUT VOLTAGE (V)
5.0
5.1
200
1751 G09
4.9
4.8
50
100
150
V
IN
= 3V
5.2
T
A
= 25°C
C
FLY
= 1µF
V
IN
= 2.7V
Output Voltage vs Output Current
No Load Supply Current
vs Input Voltage
INPUT VOLTAGE (V)
2.5
0
SUPPLY CURRENT (µA)
10
20
30
40
3.0 3.5 4.0 4.5
1751 G10
5.0 5.5
C
FLY
= 1µF
I
OUT
= 0
V
SHDN
= V
IN
T
A
= 85°C
T
A
= 25°C
T
A
= –40°C