National Instruments LM1085 Series manual Dropout Positive, Regulators, LM1085 3A Low, Features

June 2005

LM1085

3A Low Dropout Positive Regulators

LM1085 3A Low

General Description

The LM1085 is a series of low dropout positive voltage regulators with a maximum dropout of 1.5V at 3A of load current. It has the same pin-out as National Semiconductor’s industry standard LM317.

The LM1085 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 integrate the adjust resistors.

The LM1085 circuit includes a zener trimmed bandgap ref- erence, current limiting and thermal shutdown.

The LM1085 series is available in TO-220 and TO-263 pack- ages. Refer to the LM1084 for the 5A version, and the LM1086 for the 1.5A version.

Features

nAvailable in 3.3V, 5.0V, 12V and Adjustable Versions n Current Limiting and Thermal Protection

n Output Current			3A
n	Line Regulation	0.015%	(typical)
n	Load Regulation	0.1%	(typical)

Applications

nHigh Efficiency Linear Regulators n Battery Charger

n Post Regulation for Switching Supplies n Constant Current Regulator

n Microprocessor Supply

Dropout Positive

Connection Diagrams

TO-220 Application Circuit

10094702

Top View

TO-263

10094752

1.2V to 15V Adjustable Regulator

10094704

Top View

Basic Functional Diagram,

Adjustable Version

10094765

Regulators

© 2005 National Semiconductor Corporation DS100947 www.national.com