■ High Efﬁciency: Up to 96%
■ Very Low Quiescent Current: Only 20µA
■ Low Output Ripple Voltage During Burst Mode®
■ 600mA Output Current
■ 2.5V to 5.5V Input Voltage Range
■ 1.5MHz Constant Frequency Operation
■ No Schottky Diode Required
■ Low Dropout Operation: 100% Duty Cycle
■ ±2% 0.6V Reference
■ Shutdown Mode Draw ≤1µA Supply Current
■ Internal Soft-Start Limits Inrush Current
■ Current Mode Operation for Excellent Line and
Load Transient Response
■ Overtemperature Protected
■ Low Proﬁle (1mm) ThinSOTTM Package
■ Cellular Telephones
■ Wireless and DSL Modems
■ Digital Still Cameras
■ Media Players
■ Portable Instruments
■ Point of Load Regulation
Regulator in ThinSOT
The LTC®3406A is a high efﬁciency monolithic synchro-
nous buck regulator using a constant frequency, current
mode architecture. Supply current during operation is only
20μA, dropping to ≤1μA in shutdown. The 2.5V to 5.5V
input voltage range makes the LTC3406A ideally suited
for single Li-Ion battery-powered applications. 100% duty
cycle provides low dropout operation, extending battery
runtime portable systems. Automatic Burst Mode opera-
tion increases efﬁciency at light loads, further extending
Switching frequency is internally set at 1.5MHz, allowing
the use of small surface mount inductors and capacitors.
The internal synchronous switch increases efﬁciency
and eliminates the need for an external Schottky diode.
Low output voltages are easily supported with the 0.6V
feedback reference voltage. The LTC3406A is available in
a low proﬁle (1mm) ThinSOT package.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
ThinSOT is a registered trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Protected by U.S. Patents including 5481178, 6580258.
Efﬁciency vs Load Current
VIN = 2.7V
VIN = 3.6V
0 VOUT = 1.8V
VIN = 4.2V
OUTPUT CURRENT (mA)