The LM2576 series of regulators are monolithic integrated circuits that provide all the
active functions for a step-down (buck) switching regulator, capable of driving 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, 15 V, and an adjustable output version.
Requiring a minimum number of external components, these regulators are simple to use and
include fault protection and a fixed-frequency oscillator.
The LM2576 series offers a high-efficiency replacement for popular three-terminal linear
regulators. It substantially reduces the size of the heat sink, and in some cases no heat sink is
A standard series of inductors optimized for use with the LM2576 are available from
several different manufacturers. This feature greatly simplifies the design of switch-mode power
Other features include a ±4% tolerance on output voltage within specified input voltages
and output load conditions, and ±10% on the oscillator frequency. External shutdown is included,
featuring 50-µA (typical) standby current. The output switch includes cycle-by-cycle current
limiting, as well as thermal shutdown for full protection under fault conditions.