LM4871

1.1W Audio Power Amplifier with Shutdown Mode

General Description

The LM4871 is a bridge-connected audio power amplifier ca-

pable of delivering typically 1.1W of continuous average

power to an 8

Ω load with 0.5% (THD) from a 5V power sup-

ply.

Boomer audio power amplifiers were designed specifically to

provide high quality output power with a minimal amount of

external components. Since the LM4871 does not require

output coupling capacitors, bootstrap capacitors, or snubber

networks, it is optionally suited for low-power portable sys-

tems.

The LM4871 features an externally controlled, low-power

consumption shutdown mode, as well as an internal thermal

shutdown protection mechanism.

The unity-gain stable LM4871 can be configured by external

gain-setting resistors.

Key Specifications

n

THD at 1 kHz at 1W continuous

average output power into 8

Ω

0.5% (max)

n

Output power at 10% THD+N

at 1 kHz into 8

Ω

1.5W (typ)

n

Shutdown Current

0.6 µA (typ)

Features

n

No output coupling capacitors, bootstrap capacitors, or

snubber circuits are necessary

n

Small Outline or DIP packaging

n

Unity-gain stable

n

External gain configuration capability

n

Pin compatible with LM4861

Applications

n

Portable Computers

n

Desktop Computers

n

Low Voltage Audio Systems

Typical Application

Connection Diagram

DS100008-1

FIGURE 1. Typical Audio Amplifier Application Circuit

Small Outline and DIP Package

DS100008-2

Top View

Order Number LM4871M or LM4871N

See NS Package Number M08A or N08E

February 2000

© 2000 National Semiconductor Corporation

DS100008

www.national.com