LM1084

5A Low Dropout Positive Regulators

General Description

The LM1084 is a series of low dropout voltage positive

regulators with a maximum dropout of 1.5V at 5A of load

current. It has the same pin-out as National Semiconductor’s

industry standard LM317.

The LM1084 is available in an adjustable version, which can

set the output voltage with only two external resistors. It is

also available in three fixed voltages: 3.3V, 5.0V and 12.0V.

The fixed versions intergrate the adjust resistors.

The LM1084 circuit includes a zener trimmed bandgap ref-

erence, current limiting and thermal shutdown.

The LM1084 series is available in TO-220 and TO-263 pack-

ages. Refer to the LM1085 for the 3A version, and the

LM1086 for the 1.5A version.

Features

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Available in 3.3V, 5.0V, 12V and Adjustable Versions

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Current Limiting and Thermal Protection

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Output Current

5A

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Industrial Temperature Range

−40˚C to 125˚C

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Line Regulation

0.015% (typical)

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Load Regulation

0.1% (typical)

Applications

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Post Regulator for Switching DC/DC Conveter

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High Efficiency Linear Regulators

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Battery Charger

Connection Diagrams

TO-220

10094636

Top View

TO-263

10094635

Top View

Basic Functional Diagram, Adjustable Version

10094665

Application Circuit

10094652

1.2V to 15V Adjustable Regulator

June 2005

© 2005 National Semiconductor Corporation

DS100946

www.national.com