LTC3400/LTC3400B

1

3400fa

s

Pagers

s

MP3 Players

s

Digital Cameras

s

LCD Bias Supplies

s

Handheld Instruments

s

Wireless Handsets

s

GPS Receivers

s

Up to 92% Efficiency

s

Generates 3.3V at 100mA from a Single AA Cell

s

Low Start-Up Voltage: 0.85V

s

1.2MHz Fixed Frequency Switching

s

Internal Synchronous Rectifier

s

2.5V to 5V Output Range

s

Automatic Burst Mode

s

Continuous Switching at Light Loads (LTC3400B)

s

Logic Controlled Shutdown (< 1

µA)

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Antiringing Control Minimizes EMI

s

Tiny External Components

s

Low Profile (1mm) SOT-23 Package

600mA, 1.2MHz Micropower

Synchronous Boost Converter

in ThinSOT

Figure 1. Single Cell to 3.3V Synchronous Boost Converter

The LTC

quency, step-up DC/DC converters delivering high effi-

ciency in a 6-lead ThinSOT™ package. Capable of supplying

3.3V at 100mA from a single AA cell input, the devices

contain an internal NMOS switch and PMOS synchronous

rectifier.

A switching frequency of 1.2MHz minimizes solution

footprint by allowing the use of tiny, low profile inductors

and ceramic capacitors. The current mode PWM design is

internally compensated, reducing external parts count.

The LTC3400 features automatic shifting to power saving

Burst Mode operation at light loads, while the LTC3400B

features continuous switching at light loads. Antiringing

control circuitry reduces EMI concerns by damping the

inductor in discontinuous mode, and the devices feature

low shutdown current of under 1

µA.

Both devices are available in the low profile (1mm)

SOT-23 package.

ThinSOT is a trademark of Linear Technology Corporation.

SW

L1

4.7

µH

LTC3400

FB

SHDN

2

1

3

3400 F01

R1

1.02M

1%

C1, C2: TAIYO-YUDEN X5R EMK316BJ475ML

L1: COILCRAFT DO160C-472

R2

604k

1%

C2

4.7

µF

C1

4.7

µF

SINGLE

AA CELL

3.3V

100mA

5

4

6

GND

+

OFF ON

LOAD CURRENT (mA)

60

80

100

50

70

90

0.1

10

100

1000

3400 F01a

40

1

FIGURE 1 CIRCUIT

WITH OPTIONAL SCHOTTKY DIODE

(SEE APPLICATIONS INFORMATION)

Efficiency

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

, LTC, LT and Burst Mode are registered trademarks of Linear Technology Corporation.