LM4858

Mono 1.5 W / Stereo 300mW Power Amplifier

General Description

The LM4858 is an audio power amplifier capable of deliver-

ing 1.5W (typ) of continuous average power into a mono 4

Ω

bridged-tied load (BTL) with 1% THD+N or 95mW per chan-

nel of continuous average power into stereo 32

Ω single-

ended (SE) loads with 1% THD+N, using a 5V power supply.

The LM4858 can automatically switch between mono BTL

and stereo SE modes utilizing a headphone sense pin. It is

ideal for any system that provides both a monaural speaker

output and a stereo line or headphone output

Boomer audio power amplifiers were designed specifically to

provide high quality output power with a minimal amount of

external components. Since the LM4858 does not require

bootstrap capacitors or snubber networks, it is optimally

suited for low-power portable systems.

The LM4858 features an externally controlled, micropower

consumption shutdown mode and thermal shutdown protec-

tion. The unity-gain stable LM4858’s gain is set by external

gain-setting resistors

Key Specifications

n

Output Power at 1% THD+N, 1kHz:

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LM4858LD 3

Ω BTL

1.9W (typ)

n

LM4858LD 4

Ω BTL

1.7W (typ)

n

LM4858MM 4

Ω BTL

1.5W (typ)

n

LM4858MM,LD 8

Ω BTL

1.1W (typ)

n

LM4858MM,LD 8

Ω SE

300mW (typ)

n

LM4858MM,LD 32

Ω SE

95mW (typ)

n

THD+N at 1kHz, 95mW into 32

Ω SE

1% (typ)

n

Single Supply Operation

2.4 to 5.5V

n

Shutdown Current

18µA (typ)

Features

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Mono 1.5W BTL or stereo 300mW output

n

Logic controlled headphone sense

n

“Click and pop” suppression circuitry

n

No bootstrap capacitors required

n

Thermal shutdown protection

n

Unity-gain stable

n

Available in space-saving MSOP and LLP packaging

Applications

n

Portable computers

n

Desktop computers

n

PDA’s

n

Handheld games

Connection Diagrams

20064729

Top View

10 Lead MSOP

Order Number LM4858MM

See NS Package Number MUB10A

20064728

Top View

14 Lead LLP

Order Number LM4858LD

See NS Package Number LDA14A

May 2003

© 2003 National Semiconductor Corporation

DS200647

www.national.com