LTC3533
2A Wide Input Voltage
Synchronous Buck-Boost
DC/DC Converter
Description
Features
The LTC®3533 is a wide V range, highly efficient, fixed
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Regulated Output with Input Voltages Above,
IN
Below or Equal to the Output
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
continuoustransferfunctionthroughalloperatingmodes,
makingtheproductidealforsinglecelllithium-ion/polymer
or multi-cell alkaline/NiMH applications where the output
voltage is within the input voltage range.
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1.8V to 5.5V (Input) and 5.25V (Output)
Voltage Range
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0.8A Continuous Output Current: V > 1.8V
IN
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2A Continuous Output Current: V > 3V
IN
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Single Inductor
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Synchronous Rectification: Up to 96% Efficiency
Programmable Burst Mode® Operation: I = 40µA
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Q
The LTC3533 features programmable Burst Mode oper-
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Output Disconnect in Shutdown
ation, extended V and V
ranges down to 1.8V, and
IN
OUT
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Programmable Frequency from 300kHz to 2MHz
increased output current. Switching frequencies up to
2MHzareprogrammedwithanexternalresistor. TheBurst
Modethresholdisprogrammedwithasingleresistorfrom
the BURST pin to GND.
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<1µA Shutdown Current
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Small Thermally Enhanced 14-Lead (3mm × 4mm ×
0.75mm) DFN package
Otherfeaturesinclude1µAshutdowncurrent, shortcircuit
protection, programmable soft-start, current limit and
thermalshutdown.TheLTC3533ishousedinthethermally
enhanced14-lead(3mm×4mm×0.75mm)DFNpackage.
applications
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GSM Modems
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Handheld Instruments
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Digital Cameras
L, LT, LTC, LTM, Linear Technology, BurstMode and the Linear logo are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective owners.
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Smart Phones
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Media Players
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Miniature Hard Disk Drive Power
typical application
2.2μH
Efficiency
100
SW1
PV
SW2
V
3.3V
1.5A
OUT
90
80
70
V
IN
PV
IN
OUT
OUT
2.4V TO 4.2V
Burst Mode
OPERATION
340k
6.49k
47pF
V
V
IN
LTC3533
RUN/SS
60
50
OFF ON
FB
V
= 2.9V
IN
330pF
107k
V
= 2.2V
IN
R
T
V
C
40
30
20
10
0
10μF
100μF
V
= 3.9V
4.7pF
IN
BURST
PGND
0.1μF
SGND
33.2k
200k
200k
0.1
1
10
100
1000
10000
3533 TA01
OUTPUT CURRENT (mA)
3533 TA01b
3533fc
1
For more information www.linear.com/LTC3533