LM2671

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SNVS008K – SEPTEMBER 1998 – REVISED APRIL 2013

Regulator with Features

Check for Samples: LM2671

1

FEATURES

234

•

Efficiency up to 96%

DESCRIPTION

The LM2671 series of regulators are monolithic

•

Available in SOIC, 8-pin PDIP and WSON

integrated circuits built with a LMDMOS process.

Packages

These regulators provide all the active functions for a

•

Computer Design Software LM267X Made

step-down (buck) switching regulator, capable of

Simple (version 6.0)

driving a 500mA load current with excellent line and

•

Simple and Easy to Design With

load regulation. These devices are available in fixed

output voltages of 3.3V, 5.0V, 12V, and an adjustable

•

Requires Only 5 external Components

output version.

•

Uses Readily Available Standard Inductors

Requiring

a

minimum

number

of

external

•

3.3V, 5.0V, 12V, and Adjustable Output

components, these regulators are simple to use and

Versions

include patented internal frequency compensation

•

Adjustable Version Output Voltage Range:

(Patent

Nos.

5,382,918

and

5,514,947),

fixed

1.21V to 37V

frequency oscillator, external shutdown, soft-start,

and frequency synchronization.

•

±1.5% Max Output Voltage Tolerance Over

Line and Load Conditions

The LM2671 series operates at a switching frequency

•

Ensured 500mA Output Load Current

of

260

kHz,

thus

allowing

smaller

sized

filter

components than what would be needed with lower

•

0.25

Ω DMOS Output Switch

frequency switching regulators. Because of its very

•

Wide Input Voltage Range: 8V to 40V

high efficiency (>90%), the copper traces on the

•

260 kHz Fixed Frequency Internal Oscillator

printed circuit board are the only heat sinking needed.

•

TTL Shutdown Capability, Low Power Standby

A family of standard inductors for use with the

Mode

LM2671

are

available

from

several

different

manufacturers. This feature greatly simplifies the

•

Soft-Start and Frequency Synchronization

design of switch-mode power supplies using these

•

Thermal Shutdown and Current Limit

advanced ICs. Also included in the datasheet are

Protection

selector guides for diodes and capacitors designed to

work in switch-mode power supplies.

APPLICATIONS

Other features include a ensured ±1.5% tolerance on

•

Simple High Efficiency (>90%) Step-Down

output voltage within specified input voltages and

(Buck) Regulator

output load conditions, and ±10% on the oscillator

•

Efficient Pre-Regulator for Linear Regulators

frequency. External shutdown is included, featuring

typically 50

μA stand-by current. The output switch

includes current limiting, as well as thermal shutdown

for full protection under fault conditions.

To simplify the LM2671 buck regulator design

procedure, there exists computer design software,

LM267X Made Simple (version 6.0).

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

SIMPLE SWITCHER, WEBENCH are registered trademarks of Texas Instruments.

3

Windows is a registered trademark of Microsoft Corporation.

4

All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 1998–2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.