High-Performance 68W Audio Power Amplifier w/Mute

General Description

The LM3886 is a high-performance audio power amplifier

capable of delivering 68W of continuous average power to a

4

Ω load and 38W into 8Ω with 0.1% THD+N from

20Hz–20kHz.

The performance of the LM3886, utilizing its Self Peak In-

cuitry, puts it in a class above discrete and hybrid amplifiers

by providing an inherently, dynamically protected Safe Op-

erating Area (SOA). SPiKe protection means that these

parts are completely safeguarded at the output against ov-

ervoltage, undervoltage, overloads, including shorts to the

supplies, thermal runaway, and instantaneous temperature

peaks.

The LM3886 maintains an excellent signal-to-noise ratio of

greater than 92dB with a typical low noise floor of 2.0µV. It

exhibits extremely low THD+N values of 0.03% at the rated

output into the rated load over the audio spectrum, and

provides excellent linearity with an IMD (SMPTE) typical

rating of 0.004%.

Features

n

68W cont. avg. output power into 4

Ω at V

n

38W cont. avg. output power into 8

Ω at V

n

50W cont. avg. output power into 8

Ω at V

n

135W instantaneous peak output power capability

n

Signal-to-Noise Ratio

≥ 92dB

n

An input mute function

n

Output protection from a short to ground or to the

supplies via internal current limiting circuitry

n

Output over-voltage protection against transients from

inductive loads

n

Supply under-voltage protection, not allowing internal

biasing to occur when |V

≤ 12V, thus

eliminating turn-on and turn-off transients

n

11-lead TO-220 package

n

Wide supply range 20V - 94V

Applications

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Component stereo

n

Compact stereo

n

Self-powered speakers

n

Surround-sound amplifiers

n

High-end stereo TVs

Typical Application

01183301

*Optional components dependent upon specific design requirements. Refer to the External Components Description section for a component functional

description.

FIGURE 1. Typical Audio Amplifier Application Circuit

October 2003

© 2003 National Semiconductor Corporation

DS011833

www.national.com