LM22678 Datasheet | National Semiconductor Corporation

LM22678 5A SIMPLE SWITCHER®, Step-Down Voltage Regulator with Precision Enable October 17, 2008 LM22678 5A SIMPLE SWITCHER®, Step-Down Voltage Regulator .. with Precision Enable General Description The LM22678 series of regulators are monolithic integrated circuits which provide all of the active functions for a stepdown (buck) switching regulator capable of driving up to 5A loads with excellent line and load regulation characteristics. High efficiency (>90%) is obtained through the use of a low ON-resistance N-channel MOSFET. The series consists of a fixed 5V output and an adjustable version. The SIMPLE SWITCHER® concept provides for an easy to use plete design using a minimum number of external ponents and National’s WEBENCH® design tool. National’s WEBENCH® tool includes Features such as external ponent calculation, electrical simulation, thermal simulation, and Build-It boards for easy design-in. The switching clock frequency is provided by an internal fixed frequency oscillator which operates at 500 k Hz. The LM22678 series also has built in thermal shutdown, current limiting and an enable control input that can power down the regulator to a low 25 µA quiescent current standby condition. Features - - - - - - - - - - - - - Wide input voltage range: 4.5V to 42V Internally pensated voltage mode control Stable with low ESR ceramic capacitors 100 mΩ N-channel MOSFET Output voltage options: -ADJ (outputs as low as 1.285V) -5.0 (output fixed to 5V) ±1.5% feedback reference accuracy Switching frequency of 500 k Hz -40°C to 125°C operating junction temperature range Precision enable pin Integrated boot diode Integrated soft-start Fully WEBENCH® enabled Step-down and inverting buck-boost applications Package - TO-263 THIN (Exposed Pad) Applications - - - - - Industrial Control Tele and Data Systems Embedded Systems Automotive Telematics and Body Electronics Conversions from Standard 24V, 12V and 5V Input Rails Simplified...