TLH7847

December 1994

LM389 Low Voltage Audio Power Amplifier

with NPN Transistor Array

General Description

The LM389 is an array of three NPN transistors on the same

substrate with an audio power amplifier similar to the

LM386

The amplifier inputs are ground referenced while the output

is automatically biased to one half the supply voltage The

gain is internally set at 20 to minimize external parts but the

addition of an external resistor and capacitor between pins

4 and 12 will increase the gain to any value up to 200

The three transistors have high gain and excellent matching

characteristics They are well suited to a wide variety of ap-

plications in DC through VHF systems

Features

Amplifier

Y

Battery operation

Y

Minimum external parts

Y

Wide supply voltage range

Y

Low quiescent current drain

Y

Voltage gains from 20 to 200

Y

Ground referenced input

Y

Self-centering output quiescent voltage

Y

Low distortion

Transistors

Y

Operation from 1 mAto25mA

Y

Frequency range from DC to 100 MHz

Y

Excellent matching

Applications

Y

AM-FM radios

Y

Portable tape recorders

Y

Intercoms

Y

Toys and games

Y

Walkie-talkies

Y

Portable phonographs

Y

Power converters

Equivalent Schematic and Connection Diagrams

TLH7847 – 1

Dual-In-Line Package

TLH7847 – 2

Order Number LM389N

See NS Package Number N18A

C1995 National Semiconductor Corporation

RRD-B30M115Printed in U S A