FEATURES
n Burst Mode® Operation Disabled for Lower Output Ripple at Light Loads n High Efficiency: Up to 94% n High Output Currents Easily Achieved n Wide VIN Range: 2.5V to 9.8V n Constant Frequency 550kHz Operation n Low Dropout: 100% Duty Cycle n Output Voltage Down to 0.8V n Current Mode Operation for Excellent Line and Load Transient Response n Shutdown Mode Draws Only 8µA Supply Current n Tiny 6-Lead TSOT-23 Package APPLICATIONS
n One or Two Lithium-Ion-Powered APPLICATIONS
n Cellular Telephones n Wireless Devices n Portable Computers n Distributed 3.3V, 2.5V or 1.8V Power Systems DESCRIPTION
The LTC®1772B is a constant frequency current mode step-down DC/DC controller providing excellent AC and DC load and line regulation. The device incorporates an accurate undervoltage lockout feature that shuts down In shutdown, the device draws a mere 8μA. To further maximize the life of a battery source, the external P-channel MOSFET is turned on continuously in dropout (100% duty cycle). High constant operating frequency of 550kHz allows the use of a small external inductor.
Linear Technology
