LM4878

1 Watt Audio Power Amplifier in micro SMD package

with Shutdown Logic Low

General Description

The LM4878 is a bridge-connected audio power amplifier

capable of delivering1Wof continuous average power to an

8

Ω load with less than .2% (THD) 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. Since the LM4878 does not require

output coupling capacitors or bootstrap capacitors. It is op-

timally suited for low-power portable applications.

The LM4878 features an externally controlled, low-power

consumption shutdown mode, as well as an internal thermal

shutdown protection mechanism.

The unity-gain stable LM4878 can be configured by external

gain-setting resistors.

Key Specifications

1 W (typ)

0.01 µA (typ)

Features

n

Internal pulldown resistor on shutdown.

n

micro SMD package (see App. note AN-1112)

n

5V - 2V operation

n

No output coupling capacitors or bootstrap capacitors.

n

Unity-gain stable

n

External gain configuration capability

Applications

n

Cellular Phones

n

Portable Computers

n

Low Voltage Audio Systems

Typical Application

10136001

FIGURE 1. Typical Audio Amplifier Application Circuit

October 2002

© 2002 National Semiconductor Corporation

DS101360

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