LT3461 Datasheet, PDF (1/8 Pages) Linear Technology – 1.3MHz/3MHz Step-Up DC/DC Converters with Integrated Schottky in ThinSOT

LT3461/LT3461A
1.3MHz/3MHz Step-Up
DC/DC Converters with
Integrated Schottky in ThinSOT
FEATURES
■ _{Integrated Schottky Rectifier}
■ _{Fixed Frequency 1.3MHz/3MHz Operation}
■ _{High Output Voltage: Up to 38V}
■ _{Low VCESAT Switch: 260mV at 250mA}
■ _{12V at 70mA from 5V Input}
■ _{5V at 115mA from 3.3V Input}
■ _{Wide Input Range: 2.5V to 16V}
■ _{Uses Small Surface Mount Components}
■ _{Low Shutdown Current: <1µA}
■ _Soft-Start
U ^{■ Low Profile (1mm) SOT-23 (ThinSOTTM) Package}
APPLICATIO S
■ _{Digital Cameras}
■ _{CCD Bias Supply}
■ _{XDSL Power Supply}
■ _{TFT-LCD Bias Supply}
■ _{Local 5V or 12V Supply}
■ _{Medical Diagnostic Equipment}
■ _{Battery Backup}
DESCRIPTIO
The LT^®3461/LT3461A are general purpose fixed fre-
quency current mode step-up DC/DC converters. Both
devices feature an integrated Schottky and a low V_CESAT
switch allowing a small converter footprint and lower parts
cost. The LT3461 switches at 1.3MHz while the LT3461A
switches at 3MHz. These high switching frequencies en-
able the use of tiny, low cost and low height capacitors and
inductors. The constant switching frequency results in
predictable output noise that is easy to filter, and the
inductor based topology ensures an input free from switch-
ing noise typically present with charge pump solutions.
The high voltage switch in the LT3461/LT3461A is rated at
40V making the device ideal for boost converters up to
38V.
The LT3461/LT3461A are available in a low profile (1mm)
SOT-23 package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
ThinSOT is a trademark of Linear Technology Corporation.
TYPICAL APPLICATIO
5V to 12V, 70mA Step-Up DC/DC Converter
L1
V_IN
10µH
5V
1
C1
1µF
OFF ON
6 ^SW
5
V_IN V_OUT
LT3461A
4
3
SHDN FB
GND
2
261k
30.1k
V_OUT
12V
70mA
15pF
C2
1µF
3461 TA01a
Efficiency
85
80
V_IN = 5V
75
V_IN = 3.3V
70
65
60
0
20
40
60
LOAD CURRENT (mA)
80
3461 TAO1b
3461af
1