LM4700

30W Audio Power Amplifier with

Mute and Standby Modes

General Description

The LM4700 is an audio power amplifier capable of deliver-

ing typically 30W of continuous average output power into an

8

Ω load with less than 0.1% (THD + N).

The LM4700 has an independent smooth transition fade-in/

out mute and a power conserving standby mode which can

be controlled by external logic.

The performance of the LM4700, utilizing its Self Peak In-

cuitry, places it in a class above discrete and hybrid amplifi-

ers by providing an inherently, dynamically protected Safe

Operating Area (SOA). SPiKe Protection means that these

parts are completely safeguarded at the output against over-

voltage, undervoltage, overloads, including thermal runaway

and instantaneous temperature peaks.

Key Specifications

n THD+N at 1 kHz at continuous average output power of

25W into 8

Ω:

0.1% (max)

n THD+N from 20 Hz to 20 kHz at 30W of continuous

average output power into 8

Ω:

0.08% (typ)

n Standby current:

2.1 mA (typ)

Features

n SPiKe Protection

n Minimal amount of external components necessary

n Quiet fade-in/out mute function

n Power conserving standby-mode

n Isolated 11-lead TO-220 package

Applications

n Component stereo

n Compact stereo

Typical Application

Connection Diagram

DS012369-1

to the External Components Description section for a component functional

description.

FIGURE 1. Typical Audio Amplifier Application Circuit

Isolated Plastic Package

DS012369-2

Top View

Order Number LM4700TF

See NS Package Number TF11B

March 1998

© 1999 National Semiconductor Corporation

DS012369

www.national.com