Datasheet

3
LTC3440
3440fb
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Li-Ion to 3.3V Efficiency
(f
OSC
= 300kHz)
OUTPUT CURRENT (mA)
30
EFFICIENCY (%)
90
100
20
80
50
70
60
40
0.1 10 100 1000
3440 G02
1
Burst Mode
OPERATION
V
IN
= 3.3V
V
IN
= 2.5V
POWER LOSS (mW)
V
IN
= 4.2V
0.1
1
10
100
1000
f
OSC
= 1MHz
V
IN
= 3.3V
OUTPUT CURRENT (mA)
30
EFFICIENCY (%)
90
100
20
80
50
70
60
40
0.1 10 100 1000
3440 G03
1
Burst Mode
OPERATION
V
IN
= 2.5V
V
IN
= 3.3V
f
OSC
= 2MHz
V
IN
= 4.2V
Li-Ion to 3.3V Efficiency,
Power Loss (f
OSC
= 1MHz)
Li-Ion to 3.3V Efficiency
(f
OSC
= 2MHz)
Switch Pins During Buck/Boost
Switch Pins on the Edge of
Buck/Boost and Approaching Boost
SW1
2V/DIV
SW2
2V/DIV
V
IN
= 3.78V 50ns/DIV 3440 G04
V
OUT
= 3.3V
I
OUT
= 250mA
SW1
2V/DIV
SW2
2V/DIV
V
IN
= 3.42V 50ns/DIV 3440 G05
V
OUT
= 3.3V
I
OUT
= 250mA
Switch Pins on the Edge of
Buck/Boost and Approaching Buck
SW1
2V/DIV
SW2
2V/DIV
V
IN
= 4.15V 50ns/DIV 3440 G06
V
OUT
= 3.3V
I
OUT
= 250mA
Note 1: Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired.
Note 2: The LTC3440E is guaranteed to meet performance specifications
from 0°C to 70°C. Specifications over the – 40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 3: Current measurements are performed when the outputs are not
switching.
PARAMETER CONDITIONS MIN TYP MAX UNITS
Error Amp AVOL 90 dB
Error Amp Source Current 15 μA
Error Amp Sink Current 380 μA
SHDN/SS Threshold When IC is Enabled ● 0.4 1 1.5 V
When EA is at Maximum Boost Duty Cycle 2.2 V
SHDN/SS Input Current V
SHDN
= 5.5V 0.01 1 μA
ELECTRICAL CHARACTERISTICS
The ● denotes specifications that apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. V
IN
= V
OUT
= 3.6V, R
T
= 60k, unless otherwise noted.
OUTPUT CURRENT (mA)
30
EFFICIENCY (%)
90
100
20
80
50
70
60
40
0.1 10 100 1000
3440 G01
1
Burst Mode
OPERATION
V
IN
= 2.5V
V
IN
= 3.3V
f
OSC
= 300kHz
V
IN
= 4.2V