DESCRIPTION
The LTC®3408 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 0.08Ω bypass P-channel MOSFET connects VOUT directly to VIN, eliminating power loss through the inductor.

FEATURES
■ Dynamically Adjustable Output from 0.3V to 3.5V
■ 600mA Output Current
■ Internal 0.08Ω 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
■ 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