LM2598 Datasheet | National Semiconductor

Features March 1998 LM2598 SIMPLE SWITCHER ® Power Converter 150 k Hz 1A Step-Down Voltage Regulator, with Features General Description The LM2598 series of regulators are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching regulator, capable of driving a 1A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5V, 12V, and an adjustable output version. This series of switching regulators is similar to the LM2595 series, with additional supervisory and performance features added. Requiring a minimum number of external ponents, these regulators are simple to use and include internal frequency pensation†, improved line and load specifications, fixed-frequency oscillator, Shutdown /Soft-start, error flag delay and error flag output. The LM2598 series operates at a switching frequency of 150 k Hz thus allowing smaller sized filter ponents than what would be needed with lower frequency switching regulators. Available in a standard 7-lead TO-220 package with several different lead bend options, and a 7-lead TO-263 surface mount package. Typically, for output voltages less than 12V, and ambient temperatures less than 50˚C, no heat sink is required. A standard series of inductors (both through hole and surface mount types) are available from several different manufacturers optimized for use with the LM2598 series. This feature greatly simplifies the design of switch-mode power supplies. Other features include a guaranteed ± 4% tolerance on output voltage under all conditions of input voltage and output load conditions, and ± 15% on the oscillator frequency. External shutdown is included, featuring typically 85 µA standby current. Self protection features include a two stage current limit for the output switch and an over temperature shutdown for plete protection under fault conditions. Features n 3.3V, 5V, 12V, and adjustable output versions n Adjustable version output...