LM4876

1.1W Audio Power Amplifier with Shutdown Logic Low

General Description

The LM4876 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 LM4876 does not require

output coupling capacitors, bootstrap capacitors, or snubber

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

tems.

The LM4876 features an externally controlled, low-power

consumption shutdown mode, which is achieved by driving

pin 1 with logic low. Additionally, the LM4876 features an in-

ternal thermal shutdown protection mechanism.

The LM4876 is unity-gain stable and 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

0.01 µA (typ)

Features

n

No output coupling capacitors, bootstrap capacitors, or

snubber circuits are necessary

n

Small Outline packaging

n

Unity-gain stable

n

External gain configuration capability

n

Pin compatible with LM4861 and LM4871

Applications

n

Mobile Phones

n

Portable Computers

n

Desktop Computers

n

Low Voltage Audio Systems

Typical Application

Connection Diagram

DS101299-1

FIGURE 1. Typical Audio Amplifier Application Circuit

Small Outline Package

DS101299-2

Top View

Order Number LM4876M

See NS Package Number M08A

February 2000

© 2000 National Semiconductor Corporation

DS101299

www.national.com