DESCRIPTION
The LTC®1627 is a monolithic current mode synchronous buck regulator using a fixed frequency architecture. The operating supply range is from 8.5V down to 2.65V, making it suitable for one or two lithium-ion battery-powered appli cations. Burst Mode operation provides high efficiency at low load currents. 100% duty cycle provides low dropout operation, which extends operating time in battery-operated systems.

FEATURES
■ High Efficiency: Up to 96%
■ Constant Frequency 350kHz Operation
■ 2.65V to 8.5V VIN Range
■ VOUT from 0.8V to VIN, IOUT to 500mA
■ No Schottky Diode Required
■ Synchronizable Up to 525kHz
■ Selectable Burst ModeTM Operation
■ Low Dropout Operation: 100% Duty Cycle
■ Precision 2.5V Undervoltage Lockout
■ Secondary Winding Regulation
■ Current Mode Operation for Excellent Line and
   Load Transient Response
■ Low Quiescent Current: 200µA
■ Shutdown Mode Draws Only 15µA Supply Current
■ ±1.5% Reference Accuracy
■ Available in 8-Lead SO Package

APPLICATIONS
■ Cellular Telephones
■ Portable Instruments
■ Wireless Modems
■ RF Communications
■ Distributed Power Systems
■ Scanners
■ Single and Dual Cell Lithium