LT1374 Datasheet | Linear Technology

LT1374 4.5A, 500k Hz Step-Down Switching Regulator Features s s s s s s s s DESCRIPTIO Constant 500k Hz Switching Frequency Easily Synchronizable Uses All Surface Mount ponents Inductor Size Reduced to 1.8µH Saturating Switch Design: 0.07Ω Effective Supply Current: 2.5m A Shutdown Current: 20µA Cycle-by-Cycle Current Limiting The LT ®1374 is a 500k Hz monolithic buck mode switching regulator. A 4.5A switch is included on the die along with all the necessary oscillator, control and logic circuitry. High switching frequency allows a considerable reduction in the size of external ponents. The topology is current mode for fast transient response and good loop stability. Both fixed output voltage and adjustable parts are available. A special high speed bipolar process and new design techniques achieve high efficiency at high switching frequency. Efficiency is maintained over a wide output current range by using the output to bias the circuitry and by utilizing a supply boost capacitor to saturate the power switch. The LT1374 fits into standard 7-pin DD, TO-220 and fused lead SO-8 packages. Full cycle-by-cycle short-circuit protection and thermal shutdown are provided. Standard surface mount external parts are used, including the inductor and capacitors. There is the optional function of shutdown or synchronization. A shutdown signal reduces supply current to 20µA. Synchronization allows an external logic level signal to increase the internal oscillator from 580k Hz to 1MHz. , LTC and LT are registered trademarks of Linear Technology Corporation. U APPLICATIO S s s s s Portable puters Battery-Powered Systems Battery Chargers Distributed Power TYPICAL APPLICATIO 5V Buck Converter D2 1N914 C2 0.27µF INPUT 6V TO 25V VIN BOOST VSW 100 95 C3- 10µF TO 50µF + DEFAULT = ON OUTPUT- - 5V, 4.25A EFFICIENCY (%) L1- - 5µH 90 85 80 75 70 0 0.5 1.0 1.5 2.0 2.5 3.0 LOAD CURRENT (A) 3.5 4.0 LT1374-5 BIAS SHDN GND SENSE VC CC 1.5n F D1 MBRS330T3 + C1 100µF, 10V SOLID...