LM4861

1.1W Audio Power Amplifier with Shutdown Mode

General Description

The LM4861 is a bridge-connected audio power amplifier

capable of delivering 1.1W of continuous average power to

an 8

Ω load with 1% THD+N using a 5V power supply.

Boomer audio power amplifiers were designed specifically to

provide high quality output power with a minimal amount of

external components using surface mount packaging. Since

the LM4861 does not require output coupling capacitors,

bootstrap capacitors, or snubber networks, it is optimally

suited for low-power portable systems.

The LM4861 features an externally controlled, low-power

consumption shutdown mode, as well as an internal thermal

shutdown protection mechanism.

The unity-gain stable LM4861 can be configured by external

gain-setting resistors for differential gains of up to 10 without

the use of external compensation components. Higher gains

may be achieved with suitable compensation.

Key Specifications

average output power into 8

Ω

1.0% (max)

at 1kHz into 8

Ω

1.5W (typ)

0.6µA (typ)

Features

n

No output coupling capacitors, bootstrap capacitors, or

snubber circuits are necessary

n

Small Outline (SO) packaging

n

Compatible with PC power supplies

n

Thermal shutdown protection circuitry

n

Unity-gain stable

n

External gain configuration capability

Applications

n

Personal computers

n

Portable consumer products

n

Self-powered speakers

n

Toys and games

Connection Diagram

Small Outline Package

01198602

Top View

Order Number LM4861M

See NS Package Number M08A

February 2003

© 2003 National Semiconductor Corporation

DS011986

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