LM4876

1.1W Audio Power Amplifier with Logic Low Shutdown

General Description

The LM4876 is a single 5V supply bridge-connected audio

power amplifier capable of delivering 1.1W (typ) of continu-

ous average power to an 8

Ω load with 0.5% THD+N.

Like other audio amplifiers in the Boomer series, the LM4876

is designed specifically to provide high quality output power

with a minimal amount of external components. The LM4876

does not require output coupling capacitors, bootstrap ca-

pacitors, or snubber networks. It is perfectly suited for low-

power portable systems.

The LM4876 features an active low externally controlled,

micro-power shutdown mode. Additionally, the LM4876 fea-

tures an internal thermal shutdown protection mechanism.

For PCB space efficiency, the LM4876 is available in MSOP

and SO surface mount packages.

The unity-gain stable LM4876’s closed loop gain is set using

external resistors.

Key Specifications

average output power into 8

Ω

0.5% (max)

Ω

with 10% THD+N

1.5W (typ)

0.01µA (typ)

2.0V to 5.5V

Features

n

Does not require output coupling capacitors, bootstrap

capacitors, or snubber circuits

n

10-pin MSOP and 8-pin SO packages

n

Unity-gain stable

n

External gain set

Applications

n

Mobile Phones

n

Portable Computers

n

Desktop Computers

n

Low-Voltage Audio Systems

Typical Application

10129901

FIGURE 1. Typical LM4876 Audio Amplifier Application Circuit.

Numbers in ( ) are specific to the 10-pin MSOP package

March 2003

© 2003 National Semiconductor Corporation

DS101299

www.national.com