DESCRIPTION
The LTC®3406B is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. The device is available in an adjustable version and fixed output voltages of 1.5V and 1.8V. Supply current with no load is 300µA and drops to <1µA in shutdown. The 2.5V to 5.5V input voltage range makes the LTC3406B ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems. PWM pulse skipping mode operation provides very low output ripple voltage for noise sensitive applications.

FEATURES
■ High Efficiency: Up to 96%
■ 600mA Output Current at VIN = 3V
■ 2.5V to 5.5V Input Voltage Range
■ 1.5MHz Constant Frequency Operation
■ No Schottky Diode Required
■ Low Dropout Operation: 100% Duty Cycle
■ Low Quiescent Current: 300µA
■ 0.6V Reference Allows Low Output Voltages
■ Shutdown Mode Draws < 1µA Supply Current
■ Current Mode Operation for Excellent Line and
   Load Transient Response
■ Overtemperature Protected
■ Low Profile (1mm) ThinSOTTM Package

APPLICATIONS
■ Cellular Telephones
■ Personal Information Appliances
■ Wireless and DSL Modems
■ Digital Still Cameras
■ MP3 Players
■ Portable Instruments