LT1507 Datasheet | Linear Technology

LT1507 500k Hz Monolithic Buck Mode Switching Regulator Features s s s s s s s s Constant 500k Hz Switching Frequency Uses All Surface Mount ponents Operates with Inputs as Low as 4V Saturated Switch Design (0.3Ω) Cycle-by-Cycle Current Limiting Easily Synchronizable Inductor Size as Low as 2µH Shutdown Current: 20µA 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 (3.3V) and adjustable parts are available. A special high speed bipolar process and new design techniques allow this regulator to achieve high efficiency at a high switching frequency. Efficiency is maintained over a wide output current range by keeping quiescent supply current to 4m A and by utilizing a supply boost capacitor to allow the NPN power switch to saturate. A shutdown signal will reduce supply current to 20µA. The LT1507 can be externally synchronized from 570k Hz to 1MHz with logic level inputs. The LT1507 fits into standard 8-pin SO and PDIP packages. Temperature rise is kept to a minimum by the high efficiency design. Full cycle-by-cycle short-circuit protection and thermal shutdown are provided. Standard surface mount external parts are used including the inductor and capacitors. , LTC and LT are registered trademarks of Linear Technology Corporation. U APPLICATIONS s s s s Portable puters Battery-Powered Systems Battery Charger Distributed Power DESCRIPTION The LT®1507 is a 500k Hz monolithic buck mode switching regulator, functionally identical to the LT1375 but optimized for lower input voltage applications. It will operate over a 4V to 15V input range, pared with 5.5V to 25V for the LT1375. A 1.5A switch is included on the die along TYPICAL APPLICATION 5V to 3.3V Volt Down Converter D2† 1N914 C2 0.1µF VSW LT1507-3.3 DEFAULT (OPEN) = ON SHDN GND SENSE VC CC 3.3n...