LT3467/LT3467A
1.1A Step-Up DC/DC
Converter with
Integrated Soft-Start
FEATURES
DESCRIPTION
The LT®3467/LT3467A switching regulators combine a
42V, 1.1A switch with a soft-start function. Pin compatible
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1.3MHz Switching Frequency (LT3467)
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2.1MHz Switching Frequency (LT3467A)
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Low V
Switch: 330mV at 1.1A
with the LT1930, its low V
bipolar switch enables the
CESAT
CESAT
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High Output Voltage: Up to 40V
device to deliver high current outputs in a small footprint.
The LT3467 switches at 1.3MHz, allowing the use of tiny,
low cost and low height inductors and capacitors. The
LT3467A switches at 2.1MHz, allowing the use of even
smaller components. High inrush current at start-up is
eliminated using the programmable soft-start function.
A single external capacitor sets the current ramp rate. A
constantfrequencycurrentmodePWMarchitectureresults
in low, predictable output noise that is easy to filter.
Wide Input Range: 2.4V to 16V
Dedicated Soft-Start Pin
5V at 540mA from 3.3V Input (LT3467)
5V at 430mA from 3.3V Input (LT3467A)
12V at 270mA from 5V Input (LT3467)
12V at 260mA from 5V Input (LT3467A)
Uses Small Surface Mount Components
Low Shutdown Current: <1μA
Pin-for-Pin Compatible with the LT1930 and LT1613
The high voltage switch on the LT3467/LT3467A is rated
at 42V, making the devices ideal for boost converters up
to 40V as well as SEPIC and flyback designs. The LT3467
can generate 5V at up to 540mA from a 3.3V supply or
5V at 450mA from four alkaline cells in a SEPIC design.
The LT3467A can generate 5V at up to 430mA from a 3.3V
supply or 15V at 135mA from a 3.3V supply. The LT3467/
LT3467Aareavailableinalowprofile(1mm)6-leadSOT-23
package and tiny 3mm × 2mm DFN package.
™
Low Profile (1mm) ThinSOT Package
Low Profile (0.75mm) 8-Lead (3mm × 2mm)
DFN Package
APPLICATIONS
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Digital Cameras
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White LED Power Supplies
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Cellular Phones
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Medical Diagnostic Equipment
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
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Local 5V or 12V Supplies
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TFT-LCD Bias Supplies
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xDSL Power Supplies
TYPICAL APPLICATION
Efficiency
95
Single Li-Ion Cell to 5V Boost Converter
90
V
= 4.2V
2.7μH
IN
V
85
80
75
70
65
60
55
50
IN
V
OUT
5V
2.6V TO
4.2V
V
= 3.3V
IN
V
= 2.6V
765mA AT V = 4.2V,
IN
IN
IN
IN
4.7μF
402k
133k
540mA AT V = 3.3V,
V
SW
IN
360mA AT V = 2.6V
SHDN
OFF ON
3.3pF
LT3467
SS
FB
GND
15μF
0.047μF
3467 TA01a
800
900
100
300 400 500
700
200
600
I
(mA)
OUT
3467 TA01b
3467afe
1