LTC1701B

U U LTC1701/LTC1701B 1MHz Step-Down DC/DC Converters in SOT-23 FEATURES s Tiny 5-Lead SOT-23 Package s Uses Tiny Capacitors and Inductor s High Frequency Operation: 1MHz s High Output Current: 500mA s Low RDS(ON) Internal Switch: 0.28Ω s High Efficiency: Up to 94% s Current Mode Operation for Excellent Line and Load Transient Response s Short-Circuit Protected s Low Quiescent Current: 135µA (LTC1701) s Low Dropout Operation: 100% Duty Cycle s Ultralow Shutdown Current: IQ < 1µA s Peak Inductor Current Independent of Inductor Value s Output Voltages from 5V Down to 1.25V U APPLICATIO S s PDAs/Palmtop PCs s Digital Cameras s Cellular Phones s Portable Media Players s PC Cards s Handheld Equipment DESCRIPTIO The LTC®1701/LTC1701B are the industry’s first SOT-23 step-down, current mode, DC/DC converters. Intended for low to medium power applications, they operate from 2.5V to 5.5V input voltage range and switch at 1MHz, allowing the use of tiny, low cost capacitors and inductors 2mm or less in height. The output voltage is adjustable from 1.25V to 5V. A built-in 0.28Ω switch allows up to 0.5A of output current at high efficiency. OPTI-LOOPTM compensation allows the transient response to be optimized over a wide range of loads and output capacitors. The LTC1701 incorporates automatic power saving Burst ModeTM operation to reduce gate charge losses when the load current drops below the level required for continuous operation. The LTC1701B operates continuously to very low load c...