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LTC3440EMS#PBF

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P22
LTC3440
1
3440fd
For more information www.linear.com/LTC3440
Description
Micropower Synchronous
Buck-Boost DC/DC Converter
Features
applications
n
Single Inductor
n
Fixed Frequency Operation with Battery Voltages
Above, Below or Equal to the Output
n
Synchronous Rectification: Up to 96% Efficiency
n
25µA Quiescent Current in Burst Mode
®
Operation
n
Up to 600mA Continuous Output Current
n
No Schottky Diodes Required (V
OUT
< 4.3V)
n
V
OUT
Disconnected from V
IN
During Shutdown
n
2.5V to 5.5V Input and Output Range
n
Programmable Oscillator Frequency
from 300kHz to 2MHz
n
Synchronizable Oscillator
n
Burst Mode Enable Control
n
<1µA Shutdown Current
n
Small Thermally Enhanced 10-Pin MSOP and
(3mm
×
3mm) DFN Packages
n
Palmtop Computers
n
Handheld Instruments
n
MP3 Players
n
Digital Cameras
The LT C
®
3440 is a high efficiency, fixed frequency, Buck-
Boost DC/DC converter that operates from input voltages
above, below or equal to the output voltage. The topology
incorporated in the IC provides a continuous transfer
function through all operating modes, making the prod-
uct ideal for single lithium-ion, multicell alkaline or NiMH
applications where the output voltage is within the battery
voltage range.
The device includes two 0.19Ω N-channel MOSFET
switches and two 0.22Ω P-channel switches. Switch-
ing frequencies up to 2MHz are programmed with an
external resistor and the oscillator can be synchronized
to an external clock. Quiescent current is only 25µA in
Burst Mode operation, maximizing battery life in portable
applications. Burst Mode operation is user controlled and
can be enabled by driving the MODE/SYNC pin high. If the
MODE/SYNC pin has either a clock or is driven low, then
fixed frequency switching is enabled.
Other features include a 1µA shutdown, soft-start con-
trol, thermal shutdown and current limit. The LTC3440
is available in the 10-pin thermally enhanced MSOP and
(3mm × 3mm) DFN packages.
Efficiency vs V
IN
SW1
V
IN
SHDN/SS
MODE/SYNC
R
T
SW2
V
OUT
FB
V
C
GND
3
7
8
2
1
4
6
9
10
5
LTC3440
L1
10µH
R1
340k
R2
200k
R3
15k
3440 TA01
R
T
60.4k
C1: TAIYO YUDEN JMK212BJ106MG
C2: TAIYO YUDEN JMK325BJ226MM
L1: SUMIDA CDRH6D38-100
*1 = Burst Mode OPERATION
0 = FIXED FREQUENCY
C1
10µF
Li-Ion
V
IN
=
2.7V TO 4.2V
*
+
C5 1.5nF
C2
22µF
V
OUT
3.3V
600mA
V
IN
(V)
2.5
EFFICIENCY (%)
3.0
3.5
4.0 4.5
3440 TA02
5.0
100
98
96
94
92
90
88
86
84
82
80
5.5
V
OUT
= 3.3V
I
OUT
= 100mA
f
OSC
= 1MHz
typical application
Li-Ion to 3.3V at 600mA Buck-Boost Converter
L, LT, LTC, LTM, Linear Technology, Burst Mode and the Linear logo are registered trademarks
and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
LTC3440
2
3440fd
For more information www.linear.com/LTC3440
absolute MaxiMuM ratings
V
IN
, V
OUT
Voltage ....................................... –0.3V to 6V
SW1, SW2 Voltage ...................................... –0.3V to 6V
V
C
, R
T
, FB, SHDN/SS,
MODE/SYNC Voltage .................................. –0.3V to 6V
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.
Operating Temperature Range (Note 2)....–40°C to 85°C
Storage Temperature Range .................. –65°C to 125°C
Lead Temperature (Soldering, 10 sec) ................... 300°C
electrical characteristics
PARAMETER CONDITIONS MIN TYP MAX UNITS
Input Start-Up Voltage
l
2.4 2.5 V
Input Operating Range
l
2.5 5.5 V
Output Voltage Adjust Range
l
2.5 5.5 V
Feedback Voltage
l
1.196 1.22 1.244 V
Feedback Input Current V
FB
= 1.22V 1 50 nA
Quiescent Current, Burst Mode Operation V
C
= 0V, MODE/SYNC = 3V (Note 3) 25 40 µA
Quiescent Current, Shutdown SHDN = 0V, Not Including Switch Leakage 0.1 1 µA
Quiescent Current, Active V
C
= 0V, MODE/SYNC = 0V (Note 3) 600 1000 µA
NMOS Switch Leakage Switches B and C 0.1 5 µA
pin conFiguration
TOP VIEW
DD PACKAGE
10-LEAD (3mm × 3mm) PLASTIC DFN
EXPOSED PAD (PIN 11) IS GND
MUST BE SOLDERED TO PCB
10
9
6
7
8
4
5
3
2
1
V
C
FB
SHDN/SS
V
IN
V
OUT
R
T
MODE/SYNC
SW1
SW2
GND
11
T
JMAX
= 125°C, θ
JA
= 43°C/ W, θ
JC
= 3°C/W
1
2
3
4
5
R
T
MODE/SYNC
SW1
SW2
GND
10
9
8
7
6
V
C
FB
SHDN/SS
V
IN
V
OUT
TOP VIEW
MS PACKAGE
10-LEAD PLASTIC MSOP
T
JMAX
= 125°C,
θ
JA
= 130°C/W 1 LAYER BOARD
θ
JA
= 100°C/W 4 LAYER BOARD
θ
JC
= 45°C/W
orDer inForMation
LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC3440EDD#PBF LTC3440EDD#TRPBF LBKT 10-Lead (3mm × 3mm) Plastic DFN –40°C to 85°C
LTC3440EMS#PBF LTC3440EMS#TRPBF LTNP 10-Lead Plastic MSOP –40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on nonstandard lead based finish parts.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/. Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
(Note 1)
http://www.linear.com/product/LTC3440#orderinfo
LTC3440
3
3440fd
For more information www.linear.com/LTC3440
PARAMETER CONDITIONS MIN TYP MAX UNITS
PMOS Switch Leakage Switches A and D 0.1 10 µA
NMOS Switch On Resistance Switches B and C 0.19 Ω
PMOS Switch On Resistance Switches A and D 0.22 Ω
Input Current Limit
l
1 A
Maximum Duty Cycle Boost (% Switch C On)
Buck (% Switch A On)
l
l
55
100
75 %
%
Minimum Duty Cycle
l
0 %
Frequency Accuracy
l
0.8 1 1.2 MHz
MODE/SYNC Threshold 0.4 2 V
MODE/SYNC Input Current V
MODE/SYNC
= 5.5V 0.01 1 µA
Error Amp AVOL 90 dB
Error Amp Source Current 15 µA
Error Amp Sink Current 380 µA
SHDN/SS Threshold When IC is Enabled
When EA is at Maximum Boost Duty Cycle
l
0.4 1
2.2
1.5 V
V
SHDN/SS Input Current V
SHDN
= 5.5V 0.01 1 µA
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.
electrical characteristics
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.
typical perForMance characteristics
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)
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
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LTC3440EMS#PBF

Mfr. #:
Buy LTC3440EMS#PBF
Manufacturer:
Analog Devices / Linear Technology
Description:
Switching Voltage Regulators 500mA Synch. Buck-Boost Converter
Lifecycle:
New from this manufacturer.
Delivery:
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