LTC3127 Datasheet | Linear Technology

Features 1A Buck-Boost DC/DC Converter with Programmable Input Current Limit DESCRIPTION n Programmable (0.2A to 1A) ±4% Accurate Average Input Current Limit n Regulated Output with Input Voltages Above, Below or Equal to the Output n 1.8V to 5.5V (Input) and 1.8V to 5.25V (Output) Voltage Range n 0.6A Continuous Output Current: VIN > 1.8V n 1A Continuous Output Current: VIN > 3V n Single Inductor n Synchronous Rectification: Up to 96% Efficiency n Burst Mode® Operation: IQ = 35μA (Pin Selectable) n Output Disconnect in Shutdown n <1μA Shutdown Current n Small, Thermally Enhanced 10-Lead (3mm × 3mm × 0.75mm) DFN and 12-Lead MSOP Packages APPLICATIONS n USB Powered GSM Modems n Supercap Charger n Handheld Test Instruments n PC Card Modems n Wireless Terminals The LTC®3127 is a wide VIN range, highly efficient, 1.35MHz fixed frequency buck-boost DC/DC converter that operates from input voltages above, below or equal to the output voltage. The LTC3127 Features programmable average input current limit, making it ideal for power-limited input sources. The input current limit is programmed with a single resistor and is accurate from 0.2A to 1A of average input current. The topology incorporated provides a continuous transfer function through all operating modes. Other Features include <1μA shutdown current, pin-selectable Burst Mode operation and thermal overload protection. The LTC3127 is housed in thermally enhanced 10-lead (3mm × 3mm × 0.75mm) DFN packages and 12-lead MSOP packages. L, LT, LTC, LTM, Linear Technology, Burst Mode and the Linear logo are registered trademarks and Power Path and Thin SOT are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION USB or Li-Ion (500m A Maximum Input Current) to 3.3V L1 4.7µH USB OR Li-Ion 2.9V to 5.5V SW1 VIN MODE SW2 VOUT OFF ON 10µF SHDN PROG SGND PGND 32.4k L1: COILCRAFT XPL4020-472ML 320k VOUT 3.3V 182k 100p F...