LTC3406-1.2 1.5MHz, 600mA Synchronous Step-Down Regulator in ThinSOT UFEATURESDESCRIPTIO ■ High Efficiency: Up to 90% The LTC®3406-1.2 is a high efficiency monolithic syn- ■ Very Low Quiescent Current: Only 20 µ A chronous buck regulator using a constant frequency, ■ 600mA Output Current at VIN = 3V current mode architecture. Supply current during opera- ■ 2.5V to 5.5V Input Voltage Range tion with only 20µA drops <1µA in shutdown. The 2.5V to ■ 1.5MHz Constant Frequency Operation 5.5V input voltage range makes the LTC3406-1.2 ideally ■ No Schottky Diode Required suited for single Li-Ion battery-powered applications. 100% ■ Shutdown Mode Draws < 1µA Supply Current duty cycle provides low dropout operation, extending ■ Current Mode Operation for Excellent Line and battery life in portable systems. Automatic Burst Mode Load Transient Response operation further increases efficiency at light loads. ■ Overtemperature Protected Switching frequency is internally set at 1.5MHz, allowing ■ Low Profile (1mm) ThinSOTTM Package the use of small surface mount inductors and capacitors. U The internal synchronous switch increases efficiency and APPLICATIO S eliminates the need for an external Schottky diode. The LTC3406-1.2 is available in a low profile (1mm) ThinSOT ■ Cellular Telephones package. ■ Personal Information Appliances ■ Wireless and DSL Modems , LTC and LT are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. ThinSOT is a trademark of Linear ■ Digital Still Cameras Technology Corporation. Protected by U.S. Patents including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131. ■ MP3 Players ■ Portable Instruments UTYPICAL APPLICATIOEfficiency and Power LossHigh Efficiency Step-Down Converter 100 1 90 EFFICIENCY 2.2µH V 80 0.1 IN V V IN SW OUT 2.7V TO 5.5V CIN COUT 1.2V 70 POWER LOSS (W) 4.7µF 10µF 600mA LTC3406-1.2 CER CER 60 0.01 RUN V 50 OUT 340612 TA01a POWER LOSS GND 40 0.001 EFFICIENCY (%) 30 20 0.0001 VIN = 2.7V 10 VIN = 3.6V VIN = 4.2V 0 0.00001 0.1 1 10 100 1000 LOAD CURRENT (mA) 340612 TA01b 340612fa 1