LTC1779 Datasheet | Linear Technology

LTC1779 250m A Current Mode Step-Down DC/DC Converter in Thin SOT Features s s s s s s s s s DESCRIPTIO s s s High Efficiency: Up to 94% 250m A Output Current Wide VIN Range: 2.5V to 9.8V 550k Hz Constant Frequency Operation Burst Mode TM Operation at Light Load Low Dropout: 100% Duty Cycle 0.8V Reference Allows Low Output Voltages ± 2.5% Reference Accuracy Current Mode Operation for Excellent Line and Load Transient Response Low Quiescent Current: 135µA Shutdown Mode Draws Only 8µA Supply Current Low Profile (1mm) Thin SOTTM Package The LTC®1779 is a constant frequency current mode stepdown DC/DC converter in a 6-lead Thin SOT package. The part operates with a 2.5V to 9.8V input and can provide up to 250m A of output current. Current mode control provides excellent AC and DC load and line regulation. The device incorporates an accurate undervoltage lockout feature that shuts down the LTC1779 when the input voltage falls below 2V. The LTC1779 boasts a ± 2.5% output voltage accuracy and consumes only 135µA of quiescent current. For applications where efficiency is a prime consideration, the LTC1779 is configured for Burst Mode operation, which enhances efficiency at low output current. To further maximize the life of a battery source, the internal P-channel MOSFET is turned on continuously in dropout (100% duty cycle). In shutdown, the device draws a mere 8µA. High constant operating frequency of 550k Hz allows the use of a small external inductor. The LTC1779 is available in a low profile (1mm) Thin SOT package. , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode and Thin SOT are trademarks of Linear Technology Corporation. U APPLICATIO S s s s s s s 1- or 2-Cell Lithium-Ion-Powered Applications Cellular Telephones Wireless Modems Portable puters Distributed 3.3V, 2.5V or 1.8V Power Systems Scanners TYPICAL APPLICA TIO C3 0.1µF 1 20k 100p F 3 VFB SENSE - 4 ITH/RUN LTC1779 GND VIN SW 6 D1 R1 10Ω L1 22µH C1 10µF 16V VIN 2.5V TO...