LTC3403 Datasheet - Linear Technology

DESCRIPTION
The LTC®3403 is a high efficiency monolithic synchronous buck regulator optimized for WCDMA power amplifier applications. The output voltage can be dynamically programmed from 0.3V to 3.5V. At VOUT > 3.6V an internal bypass P-channel MOSFET connects VOUT directly to VIN, eliminating power loss through the inductor. Selectable forced continuous mode enables fast VOUT response to the controlling input.

FEATURES
■ Dynamically Adjustable Output from 0.3V to 3.5V
■ Very Low Quiescent Current: Only 20µA
   During Operation
■ 600mA Output Current
■ Internal P-Channel MOSFET Bypass Transistor
■ High Efficiency: Up to 96%
■ 1.5MHz Constant Frequency Operation
■ No Schottky Diode Required
■ Low Dropout Operation: 100% Duty Cycle
■ 2.5V to 5V Input Voltage Range
■ Drives Optional External P-Channel MOSFET
■ Shutdown Mode Draws < 1µA Supply Current
■ Current Mode Operation for Excellent Line and
   Load Transient Response
■ Overtemperature Protected
■ Available in 8-Lead 3mm × 3mm DFN Package

APPLICATIONS
■ WCDMA Cell Phone Power Amplifiers
■ Wireless Modems