LM2576 Series

Description

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 3A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V,

5V, 12V, 15V, and an adjustable output versions. Requiring a minimum number of external components, these regulators are simple to

use and include internal frequency compensation 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 guaranteed ± 4%

tolerance on output voltage within specified input voltages and output load conditions, and ±10% on the oscillator frequency. External

shutdown is included, featuring 50µA (typical) standby current. The output switch includes cycle-by-cycle current limiting, as well as

thermal shutdown for full protection under fault conditions.

Note:

Features

•

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

•

Adjustable version output voltage range

•

1.23V to 37V (57V for HV version) ± 4% max over line

and load conditions

•

Guaranteed 3A output current

•

Wide input voltage range, 40V up to 60V for HV

version

•

Requires only 4 external components

•

52 kHz fixed frequency oscillator

•

TTL shutdown capability, low power standby mode

•

High efficiency

•

Uses readily available standard inductors

•

Thermal shutdown and current limit protection

Applications

•

Simple high-efficiency step-down (buck) regulator

•

Efficient pre-regulator for linear regulators

•

On-card switching regulators

•

Positive to negative converter (Buck-Boost)

7V - 40V

(60V for HV)

UNREGULATED

1

LM2576/

LM2576HV-

5.0

FEEDBACK

4

OUTPUT

2

L1

+5V

REGULATED

DC INPUT

+

3

GND

5 ON/OFF

100

H

D1

1N5822

1000

F

OUTPUT

3A

LOAD

1

TIGER ELECTRONICS CO.,LTD

TIGER ELECTRONIC CO.,LTD