LTC3772B Datasheet | Linear Technology

Micropower No RSENSE Constant Frequency Step-Down DC/DC Controller Features - No Current Sense Resistor Required - High Output Currents Easily Achieved - Internal Soft-Start Ramps VOUT - Wide VIN Range: 2.75V to 9.8V - Low Dropout: 100% Duty Cycle - Constant Frequency 550k Hz Operation - Low Ripple Pulse Skipping Operation at Light Load - Output Voltage as Low as 0.8V - ±1.5% Voltage Reference Accuracy - Current Mode Operation for Excellent Line and Load Transient Response - Only 8µA Supply Current in Shutdown - Low Profile 8-Lead SOT-23 (1mm) and (3mm × 2mm) DFN (0.75mm) Packages U APPLICATIO S - 1- or 2-Cell Li-Ion Battery-Powered Applications - Wireless Devices - Portable puters - Distributed Power Systems DESCRIPTIO The LTC®3772B is a constant frequency current mode step-down DC/DC controller in a low profile 8-lead SOT-23 (Thin SOTTM) and a 3mm × 2mm DFN package. The No RSENSETM architecture eliminates the need for a current sense resistor, improving efficiency and saving board space. The LTC3772B automatically switches into pulse skipping operation at light loads. It consumes only 200µA of quiescent current under a no-load condition. The LTC3772B incorporates an undervoltage lockout feature that shuts down the device when the input voltage falls below 2V. To maximize the runtime from a battery source, the external P-channel MOSFET is turned on continuously in dropout (100% duty cycle). High switching frequency of 550k Hz allows the use of a small inductor and capacitors. An internal soft-start smoothly ramps the output voltage from zero to its regulation point. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Thin SOT and No RSENSE are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5731694, 6127815. TYPICAL APPLICATIO 550k Hz Micropower Step-Down DC/DC Converter 680p F...