LM4864

300 mW Audio Power Amplifier with Shutdown Mode

General Description

The LM4864 is a bridged audio power amplifier capable of

delivering 300 mW of continuous average power into an 8

Ω

load with 1% (THD) from a 5V power supply.

to provide high quality output power from a low supply volt-

age while requiring a minimal amount of external compo-

nents. Since the LM4864 does not require output coupling

capacitors, bootstrap capacitors or snubber networks, it is

optimally suited for low-power portable applications.

The LM4864 features an externally controlled, low power

consumption shutdown mode, and thermal shutdown protec-

tion.

The closed loop response of the unity-gain stable LM4864,

can be configured by external gain-setting resistors. The de-

vice is available in multiple package types to suit various ap-

plications.

Key Specifications

n THD at 1 kHz at 300 mW continuous

average output power into 8

Ω

1.0% (max)

n THD at 1 kHz at 300 mW continuous

average output power into 16

Ω

1.0% (max)

n Shutdown current

0.7 µA (typ)

Features

n MSOP, SOP, and DIP packaging

n No output coupling capacitors, bootstrap capacitors, or

snubber circuits are necessary

n Thermal shutdown protection circuitry

n Unity-gain stable

n External gain configuration capability

Applications

n Cellular Phones

n Personal Computers

n General Purpose Audio

Typical Application

Connection Diagram

DS012607-1

FIGURE 1. Typical Audio Amplifier Application Circuit

MSOP, SOP, and DIP Package

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Top View

Order Number LM4864MM,

LM4864M or LM4864N

See NS Package Number MUA08A,

M08A or N08E

September 1999

© 1999 National Semiconductor Corporation

DS012607

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