LM4857 Datasheet, PDF(1/38 Page) National Semiconductor (TI) – Stereo 1.2W Audio Sub-system with 3D Enhancement

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LM4857 Datasheet, PDF (1/38 Pages) National Semiconductor (TI) – Stereo 1.2W Audio Sub-system with 3D Enhancement

June 2004

LM4857

Stereo 1.2W Audio Sub-system with 3D Enhancement

General Description

The LM4857 is an integrated audio sub-system designed for

stereo cell phone applications. Operating on a 3.3V supply, it

combines a stereo speaker amplifier delivering 495mW per

channel into an 8â¦ load, a stereo headphone amplifier de-

livering 33mW per channel into a 32â¦ load, a mono earpiece

amplifier delivering 43mW into a 32â¦ load, and a line output

for an external powered handsfree speaker. It integrates the

audio amplifiers, volume control, mixer, power management

control, and National 3D enhancement all into a single pack-

age. In addition, the LM4857 routes and mixes the stereo

and mono inputs into 16 distinct output modes. The LM4857

is controlled through an I2C compatible interface. Other fea-

tures include an ultra-low current shutdown mode and ther-

mal shutdown protection.

Boomer audio power amplifiers are designed specifically to

provide high quality output power with a minimal amount of

external components.

The LM4857 is available in a 30-bump ITL package and a

28âlead LLP package.

Key Specifications

j POUT, Stereo Loudspeakers, 4â¦, 5V,

1% THD+N (LM4857SP)

j POUT, Stereo Loudspeakers, 8â¦, 5V,

1% THD+N

j POUT, Stereo Headphones, 32â¦, 5V,

1% THD+N

j POUT, Mono Earpiece, 32â¦, 5V,

1% THD+N

j POUT, Stereo Loudspeakers, 8â¦, 3.3V,

1% THD+N

j POUT, Stereo Headphones, 32â¦, 3.3V,

1% THD+N

j POUT, Mono Earpiece, 32â¦, 3.3V,

1% THD+N

j Shutdown Current

1.6W (typ)

1.2W (typ)

75mW (typ)

100mW (typ)

495mW (typ)

33mW (typ)

43mW (typ)

0.06ÂµA (typ)

Features

n Stereo speaker amplifier

n Stereo headphone amplifier

n Mono earpiece amplifier

n Mono Line Output for external handsfree carkit

n Independent Left, Right, and Mono volume controls

n National 3D enhancement

n I2C compatible interface

n Ultra low shutdown current

n Click and Pop Suppression circuit

n 16 distinct output modes

n Thermal Shutdown Protection

n Available in micro SMD and LLP packages

Applications

n Cell Phones

n PDAs

n Portable Gaming Devices

n Internet Appliances

n Portable DVD/CD/AAC/MP3 players

BoomerÂ® is a registered trademark of National Semiconductor Corporation.

www.national.com

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