LTC3400B_15 Datasheet, PDF (1/12 Pages) Linear Technology – 600mA, 1.2MHz Micropower Synchronous Boost Converter in ThinSOT

LTC3400/LTC3400B
600mA, 1.2MHz Micropower
Synchronous Boost Converter
in ThinSOT
FEATURES
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}^® _{Operation (LTC3400)}
s _{Continuous Switching at Light Loads (LTC3400B)}
s _{Logic Controlled Shutdown (< 1µA)}
s _{Antiringing Control Minimizes EMI}
s _{Tiny External Components}
s _{Low Profile (1mm) SOT-23 Package}
U
APPLICATIO S
s _Pagers
s _{MP3 Players}
s _{Digital Cameras}
s _{LCD Bias Supplies}
s _{Handheld Instruments}
s _{Wireless Handsets}
s _{GPS Receivers}
DESCRIPTIO
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.
, LTC, LT and Burst Mode are registered trademarks of Linear Technology Corporation.
ThinSOT is a trademark of Linear Technology Corporation.
TYPICAL APPLICATIO
+ _SINGLE
AA CELL
L1
4.7µH
C1
4.7µF
1
SW
6
5
V_IN V_OUT
OFF ON
LTC3400
4
3
SHDN FB
GND
2
C1, C2: TAIYO-YUDEN X5R EMK316BJ475ML
L1: COILCRAFT DO160C-472
R1
1.02M
1%
R2
604k
1%
V_OUT
3.3V
100mA
C2
4.7µF
3400 F01
Figure 1. Single Cell to 3.3V Synchronous Boost Converter
Efficiency
100
V_IN = 2.4V
90
80
V_IN = 1.5V
70
60
50
FIGURE 1 CIRCUIT
WITH OPTIONAL SCHOTTKY DIODE
(SEE APPLICATIONS INFORMATION)
40
0.1
1
10
100
LOAD CURRENT (mA)
1000
3400 F01a
3400fa
1