LM2576SX-5.0 NOPB.pdf

Features for the LM2576

Newer products available:

LMR33630 36-V, 3-A, 400-kHz synchronous converter

LM76003 60-V, 3.5-A, 2.2-MHz synchronous converter

3.3-V, 5-V, 12-V, 15-V, and adjustable output versions

Adjustable version output voltage range,1.23 V to 37 V (57 V for HV version) ±4% maximum over line and load conditions

Specified 3-A output current

Wide input voltage range: 40 V Up to 60 V for HV version

Requires only four external components

52-kHz fixed-frequency internal oscillator

TTL-shutdown capability, low-power standby mode

High efficiency

Uses readily available standard inductors

Create a custom design using the LMR33630 or LM76003 with the WEBENCH Power Designer

Description for the LM2576

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 new product, LMR33630, offers reduced BOM cost, higher efficiency, and an 85% reduction in solution size among many other features. 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.