Datasheet

LTC3400/LTC3400B
1
3400fa
Pagers
MP3 Players
Digital Cameras
LCD Bias Supplies
Handheld Instruments
Wireless Handsets
GPS Receivers
Up to 92% Efficiency
Generates 3.3V at 100mA from a Single AA Cell
Low Start-Up Voltage: 0.85V
1.2MHz Fixed Frequency Switching
Internal Synchronous Rectifier
2.5V to 5V Output Range
Automatic Burst Mode
®
Operation (LTC3400)
Continuous Switching at Light Loads (LTC3400B)
Logic Controlled Shutdown (<1µA)
Antiringing Control Minimizes EMI
Tiny External Components
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
®
3400/LTC3400B are synchronous, fixed fre-
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 1µA.
Both devices are available in the low profile (1mm)
SOT-23 package.
ThinSOT is a trademark of Linear Technology Corporation.
SW
L1
4.7µH
V
OUT
LTC3400
FB
V
IN
SHDN
2
1
3
3400 F01
R1
1.02M
1%
C1, C2: TAIYO-YUDEN X5R EMK316BJ475ML
L1: COILCRAFT DO160C-472
R2
604k
1%
C2
4.7µF
C1
4.7µF
SINGLE
AA CELL
V
OUT
3.3V
100mA
5
4
6
GND
+
OFF
ON
LOAD CURRENT (mA)
60
EFFICIENCY (%)
80
100
50
70
90
0.1 10 100 1000
3400 F01a
40
1
V
IN
= 2.4V
V
IN
= 1.5V
FIGURE 1 CIRCUIT
WITH OPTIONAL SCHOTTKY DIODE
(SEE APPLICATIONS INFORMATION)
Efficiency
FEATURES
DESCRIPTIO
U
APPLICATIO S
U
TYPICAL APPLICATIO
U
, LTC, LT and Burst Mode are registered trademarks of Linear Technology Corporation.

Summary of content (12 pages)