LM4860

Series 1W Audio Power Amplifier with Shutdown Mode

General Description

The LM4860 is a bridge-connected audio power amplifier

capable of delivering 1W of continuous average power to an

8

Ω load with less than 1% THD+N over the audio spectrum

from 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 LM4860 does not require output coupling capacitors,

bootstrap capacitors or snubber networks, it is optimally

suited for low-power portable systems.

The LM4860 features an externally controlled, low-power

consumption shutdown mode, as well as an internal thermal

shutdown protection mechanism. It also includes two head-

phone control inputs and a headphone sense output for

external monitoring.

The unity-gain stable LM4860 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

n

THD+N at 1W continuous average

output power into 8

Ω: 1% (max)

n

Instantaneous peak output power:

n

Shutdown current:

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

n

Two headphone control inputs and headphone sensing

output

Applications

n

Personal computers

n

Portable consumer products

n

Cellular phones

n

Self-powered speakers

n

Toys and games

Typical Application

Connection Diagram

Small Outline Package

01198802

Top View

Order Number LM4860M

See NS Package Number M16A

Patents pending.

01198801

FIGURE 1. Typical Audio Amplifier Application Circuit

August 2000

© 2004 National Semiconductor Corporation

DS011988

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