Datasheet

LTC3240-3.3/LTC3240-2.5
4
3240fb
No-Load Input Current
vs Supply Voltage (LTC3240-3.3)
Mode Switch Threshold
vs Load Current (LTC3240-3.3)
Effi ciency vs Supply Voltage
(LTC3240-3.3)
V
OUT
Soft-Start (LTC3240-3.3)
Output Noise/Ripple
(LTC3240-3.3)
TYPICAL PERFOR A CE CHARACTERISTICS
UW
(T
A
= 25°C, C
FLY
= C
IN
= 1µF, C
OUT
= 4.7µF
unless otherwise noted)
Effective Open-Loop Resistance
vs Temperature (LTC3240-3.3)
TEMPERATURE (°C)
–40
EFFECTIVE OPEN-LOOP RESISTANCE (Ω)
8
9
10
60
3240 G07
7
6
5
–15
10
35
85
V
IN
= 1.8V
V
OUT
= 3V
SUPPLY VOLTAGE (V)
1.7
0
NO-LOAD INPUT CURRENT (µA)
10
30
40
50
100
70
2.7
3.7
4.2
3240 G08
20
80
90
60
2.2 3.2
4.7
5.2
5.7
No-Load Input Current
vs Supply Voltage (LTC3240-2.5)
SUPPLY VOLTAGE (V)
1.7
0
NO-LOAD INPUT CURRENT (µA)
10
30
40
50
100
70
2.7
3.7
4.2
3240 G09
20
80
90
60
2.2 3.2
4.7
5.2
5.7
I
LOAD
(mA)
0
V
IN
(V)
3.60
3.70
160
3240 G10

3.50
3.40
40
80
120
20
60
100
140
3.80
3.55
3.65
3.45
3.75
DOUBLER TO
LDO MODE
(V
IN
RISING)
LDO TO
DOUBLER MODE
(V
IN
FALLING)
Mode Switch Threshold
vs Load Current (LTC3240-2.5)
I
LOAD
(mA)
0
2.65
V
IN
(V)
2.70
2.75
2.80
2.85
40 80
120
160
3240 G11
2.90
2.95
20 60
100
140
DOUBLER TO LDO
MODE (V
IN
RISING)
LDO TO DOUBLER
MODE (V
IN
FALLING)
SUPPLY VOLTAGE (V)
1.80
0
EFFICIENCY (%)
10
30
40
50
100
70
2.80
3.80
4.30
3240 G12
20
80
90
60
2.30 3.30
4.80
5.30
5.80
I
LOAD
= 40mA
I
LOAD
= 1mA
LDO TO DOUBLER
MODE (V
IN
FALLING)
DOUBLER TO LDO
MODE (V
IN
RISING)
V
OUT
2V/DIV
200µs/DIV
3240 G13
V
IN
= 2.4V
R
LOAD
= 66Ω
SHDN
2V/DIV
V
OUT
20mV/DIV
AC COUPLED
500ns/DIV
3240 G14
V
IN
= 2.4V
I
LOAD
= 100mA