SIMPLE SWITCHER® 40V, 3A Low Component Count Step-Down Regulator

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 required.

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 supplies.

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.

The LM76003

requires very few external components and has a pinout designed for simple, optimum PCB

layout for EMI and thermal performance. See the device comparison table to compare specs.