LTC1874 Datasheet | Linear Technology

LTC1874 Dual Constant Frequency Current Mode Step-Down DC/DC Controller Features s s s s s s s s DESCRIPTIO s s s s s s High Efficiency: Up to 94% High Output Currents Easily Achieved Wide VIN Range: 2.5V to 9.8V Constant Frequency 550k Hz Operation Burst Mode TM Operation at Light Load Low Dropout: 100% Duty Cycle 0.8V Reference Allows Low Output Voltages Current Mode Operation for Excellent Line and Load Transient Response Low Quiescent Current: 270µA (Each Controller) Separate Shutdown Pin for Each Controller Shutdown Mode Draws Only 8µA Supply Current (Each Controller) ± 2.5% Reference Accuracy Available in 16-Lead Narrow SSOP Each Controller Functions Independent of the Other The LTC®1874 is a dual constant frequency current mode step-down DC/DC controller with excellent AC and DC load and line regulation. Each controller has an accurate undervoltage lockout that shuts down the individual controller when the input voltage falls below 2.0V. The LTC1874 boasts ± 2.5% output voltage accuracy and consumes only 270µA of quiescent current per controller. The LTC1874 is configured with Burst Mode operation, which enhances efficiency at low output current for applications where efficiency is a prime consideration. To further maximize the life of a battery source, each external P-channel MOSFET is turned on continuously in dropout (100% duty cycle). In shutdown, each controller draws a mere 8µA. High constant operating frequency of 550k Hz allows the use of small external inductors. The LTC1874 is available in a small footprint 16-lead narrow SSOP. , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a trademark of Linear Technology Corporation. U APPLICATIO S s s s s 1- or 2-Cell Lithium-Ion-Powered Applications Personal Information Appliances Portable puters Distributed 3.3V, 2.5V or 1.8V Power Systems TYPICAL APPLICATION VIN 3.5V TO 9.5V CIN 10µF 16V ×2 L1 M1 4.7µH R1 0.04Ω 1 2 3 4 10k 220p F 13 14 15 80.6k 16 LTC1874 8...