The LTC1773 is a current mode synchronous buck regulator controller that drives external complementary power MOSFETs using a fixed frequency architecture. The operating supply range is from 2.65V to 8.5V, making it suitable for 1- or 2-cell lithium-ion battery powered applications. 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. The operating frequency is internally set at 550kHz, allowing the use of small surface mount inductors. For switching-noise sensitive applications, it can be synchronized up to 750kHz. Peak current limit is user programmable with an external high side sense resistor. A SYNC/FCB control pin guarantees regulation of secondary windings regardless of load on the main output by forcing continuous operation. Burst Mode operation is inhibited during synchronization or when the SYNC/FCB pin is pulled low to reduce noise and RF interference. Soft-start is provided by an external capacitor. Synchronous rectification increases efficiency and eliminates the need for a Schottky diode, saving components and board space. The LTC1773 comes in a 10-lead MSOP package. Applications * Cellular Telephones * RF PA Supply * Portable Instruments * Wireless MODEMS * Distributed Power Systems * Notebook and Palm Top Computers, PDAs * Single and Dual Cell Lithium-Ion Powered Devices * High Efficiency: Up to 95% * Constant Frequency 550kHz Operation * VIN from 2.65V to 8.5V * VOUT from 0.8V to VIN * OPTI-LOOP® Compensation Minimizes COUT * Synchronizable up to 750kHz * Selectable Burst Mode Operation * Low Quiescent Current: 80µA * Low Dropout Operation: 100% Duty Cycle * Secondary Winding Regulation * Soft-Start * Current Mode Operation for Excellent Line and Load Transient Response * Low Quiescent Current: 80µA * Low Shutdown IQ = 10µA * ±1.5% Reference Accuracy * Precision 2.5V Undervoltage Lockout * Available in 10-Lead MSOP https://elecena.pl/product/253001/synchronous-step-down-dc-dc-controller 2007-03-02 https://elecena.pl/product/253001/synchronous-step-down-dc-dc-controller 2014-04-09 https://elecena.pl/product/253001/synchronous-step-down-dc-dc-controller 2025-01-21