LTC3422 View Datasheet(PDF) - Linear Technology
Part Name
Description
Manufacturer
LTC3422 Datasheet PDF : 16 Pages
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LTC3422
1.5A, 3MHz Synchronous
Step-Up DC/DC Converter
with Output Disconnect
FEATURES
■ 700mA Continuous/1A Pulsed Output Current
for Li-Ion to 5V Applications
■ Synchronous Rectification: Up to 96% Efficiency
■ True Output Disconnect
■ Inrush Current Limiting
■ Adjustable Automatic Burst Mode® Operation
■ Low Noise, Fixed Frequency Operation from
100kHz to 3MHz
■ 0.5V to 4.5V Input Range
■ 2.25V to 5.25V Adjustable Output Voltage
■ Guaranteed 1V Start-Up
■ Programmable Soft-Start
■ Synchronizable Oscillator
■ Low Quiescent Current: 25µA
■ < 1µA Shutdown Current
■ Anti-Ringing Control
■ Small (3mm × 3mm × 0.75mm) Thermally Enhanced
10-Pin DFN Package
U
APPLICATIO S
■ Wireless Handsets
■ Handheld Computers
■ GPS Receivers
■ MP3 Players
DESCRIPTIO
The LTC®3422 is a high efficiency, current mode, fixed
frequency, step-up DC/DC converter with true output
disconnect and inrush current limiting. The part is guaran-
teed to start up from an input voltage of 1V. The device
includes a 0.20Ω N-channel MOSFET switch and a 0.24Ω
P-channel MOSFET synchronous rectifier. The output
voltage, switching frequency, soft-start time, Burst Mode
threshold and loop compensation are all simply pro-
grammed using tiny external passive components.
Quiescent current is only 25µA during Burst Mode opera-
tion, maximizing battery life in portable applications. The
oscillator frequency can be programmed up to 3MHz and
can be synchronized to an external clock applied to the
SYNC pin.
Other features include 1µA shutdown, short-circuit protec-
tion, anti-ringing control, thermal shutdown and current
limit. The LTC3422 is available in a (3mm × 3mm × 0.75mm)
10-pin DFN package.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
Burst Mode is a registered trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATIO
VIN
1.8V TO 3.2V +
2 CELLS
4.7µF
4.7µH
VIN
SW
SYNC
VOUT
LTC3422
OFF ON
SHDN
FB
VC
BURST
1nF
SS
RT GND
15k
22pF
0.1µF 28k
22µF
VOUT
3.3V
600mA
931k
549k
2.2nF 301k
3422 TA01a
2.4V to 3.3V Efficiency and Power Loss
100
BURST
90 EFFICIENCY
80
10000
1000
70
PWM
EFFICIENCY
60
100
50
40
30
20
10
0
0.1
PWM
10
POWER
LOSSES
BURST
1
POWER
LOSSES
fOSC = 1MHz 0
1
10
100
1000
LOAD CURRENT (mA)
3422 TA01b
3422fa
1
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