LTC3406A 1.5MHz, 600mA Synchronous Step-Down Regulator in ThinSOT FEATURESDESCRIPTION ■ High Effi ciency: Up to 96% The LTC®3406A is a high effi ciency monolithic synchro- ■ Very Low Quiescent Current: Only 20µA nous buck regulator using a constant frequency, current ■ Low Output Ripple Voltage During Burst Mode® mode architecture. Supply current during operation is only Operation 20μA, dropping to ≤1μA in shutdown. The 2.5V to 5.5V ■ 600mA Output Current input voltage range makes the LTC3406A ideally suited ■ 2.5V to 5.5V Input Voltage Range for single Li-Ion battery-powered applications. 100% duty ■ 1.5MHz Constant Frequency Operation cycle provides low dropout operation, extending battery ■ No Schottky Diode Required runtime portable systems. Automatic Burst Mode opera- ■ Low Dropout Operation: 100% Duty Cycle tion increases effi ciency at light loads, further extending ■ ±2% 0.6V Reference battery runtime. ■ Shutdown Mode Draw ≤1µA Supply Current Switching frequency is internally set at 1.5MHz, allowing ■ Internal Soft-Start Limits Inrush Current the use of small surface mount inductors and capacitors. ■ Current Mode Operation for Excellent Line and The internal synchronous switch increases effi ciency Load Transient Response and eliminates the need for an external Schottky diode. ■ Overtemperature Protected Low output voltages are easily supported with the 0.6V ■ Low Profi le (1mm) ThinSOTTM Package feedback reference voltage. The LTC3406A is available in APPLICATIONS a low profi le (1mm) ThinSOT package. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. ■ Cellular Telephones ThinSOT is a registered trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. ■ Wireless and DSL Modems Protected by U.S. Patents including 5481178, 6580258. ■ Digital Still Cameras ■ Media Players ■ Portable Instruments ■ Point of Load Regulation TYPICAL APPLICATIONEffi ciency vs Load Current 100 2.2μH V 90 OUT VIN VIN SW 1.8V 80 22pF 4.7μF 600mA CER LTC3406A 10μF 70 CER 60 RUN VFB 50 619k GND 309k 40 EFFICIENCY (%) 30 3406A TA01 20 VIN = 2.7V 10 VIN = 3.6V V V OUT = 1.8V IN = 4.2V 0 0.1 1 10 100 1000 OUTPUT CURRENT (mA) 3406A TA01b 3406afa 1