LTC3406AB Datasheet, PDF (1/16 Pages) Linear Technology – 1.5MHz, 600mA Synchronous Step-Down Regulator in ThinSOT

FEATURES
■ _{High Efficiency: Up to 96%}
■ _{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}
■ _{Low Quiescent Current: 200μA}
■ _{±2% 0.6V Reference}
■ _{Shutdown Mode Draws <1μA Supply Current}
■ _{Internal Soft-Start Limits Inrush Current}
■ _{Current Mode Operation for Excellent Line and}
Load Transient Response
■ _{Overtemperature Protected}
■ _{Low Profile (1mm) ThinSOT}^TM _Package
APPLICATIONS
■ _{Cellular Telephones}
■ _{Satellite and GPS Receivers}
■ _{Wireless and DSL Modems}
■ _{Digital Still Cameras}
■ _{Media Players}
■ _{Portable Instruments}
LTC3406AB
1.5MHz, 600mA
Synchronous Step-Down
Regulator in ThinSOT
DESCRIPTION
The LTC^®3406AB is a high efficiency monolithic synchro-
nous buck regulator using a constant frequency, current
mode architecture. Supply current with no load is 200μA,
dropping to <1μA in shutdown. The 2.5V to 5.5V input
voltage range makes the LTC3406AB ideally suited for
single Li-Ion battery-powered applications. 100% duty
cycle provides low dropout operation, extending battery
run time in portable systems. PWM pulse skipping mode
operation provides very low output ripple voltage for noise
sensitive applications. Refer to LTC3406A for applications
that require Burst Mode^® operation.
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 LTC3406AB is available
in a low profile (1mm) ThinSOT package.
, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology
Corporation. ThinSOT is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Protected by U.S. Patents including 5481178, 6580258.
TYPICAL APPLICATION
2.2μH
V_IN
V_IN
SW
4.7μF
CER
LTC3406AB
22pF
RUN V_FB
GND
619k
309k
3406AB TA09
1.8V, 600mA
V_OUT
10μF
CER
Efficiency vs Load Current
100
V_OUT = 1.8V
90
80
70
60
50
40
30
20
10
0.1
V_IN = 2.7V
V_IN = 3.6V
V_IN = 4.2V
1
10
100
OUTPUT CURRENT (mA)
1000
3406B TA14
3406abfa
1