The LM2599 series of regulators are monolithic integrated circuits that provide all the
active functions for a step-down (buck) switching regulator, capable of driving a 3-A load with
excellent line and load regulation. These devices are available in fixed output voltages of 3.3 V,
5 V, 12 V, and an adjustable output version.
The LM2598 is a member of the LM259x family, with additional supervisory and performance
Requiring a minimum number of external components, these regulators are simple to use and
include internal frequency compensation, improved line and load specifications, fixed-frequency
oscillator, Shutdown and Soft-start, error flag delay, and error flag
The LM2599 series operates at a switching frequency of 150 kHz, thus allowing smaller
sized filter components than what would be needed with lower frequency switching regulators.
Available in a standard 7-pin TO-220 package with several different lead bend options, and a 7-pin
TO-263 surface-mount package.
A standard series of inductors (both through-hole and surface-mount types) are available
from several different manufacturers optimized for use with the LM2599 series. This feature greatly
simplifies the design of switch-mode power supplies.
Other features include a ±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 80-µA standby current. Self-protection features include a two stage
current limit for the output switch and an overtemperature shutdown for complete protection under