LM4857 Datasheet, PDF (1/39 Pages) National Semiconductor (TI) – Stereo 1.2W Audio Sub-system with 3D Enhancement

LM4857
www.ti.com
SNAS229I – OCTOBER 2003 – REVISED APRIL 2013
LM4857
Stereo 1.2W Audio Sub-system with 3D
Enhancement
Check for Samples: LM4857
FEATURES
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•2 Stereo Speaker Amplifier
• Stereo Headphone Amplifier
• Mono Earpiece Amplifier
• Mono Line Output for External Handsfree
Carkit
• Independent Left, Right, and Mono Volume
Controls
• TI 3D Enhancement
• I²C Compatible Interface
• Ultra low Shutdown Current
• Click and Pop Suppression Circuit
• 16 distinct Output Modes
• Thermal Shutdown Protection
• Available in DSBGA and UQFN packages
KEY SPECIFICATIONS
• POUT, Stereo Loudspeakers, 4Ω, 5V, 1%
THD+N (LM4857SP) 1.6W (typ)
• POUT, Stereo Loudspeakers, 8Ω, 5V, 1%
THD+N 1.2W (typ)
• POUT, Stereo Headphones, 32Ω, 5V, 1%
THD+N 75mW (typ)
• POUT, Mono Earpiece, 32Ω, 5V, 1% THD+N
100mW (typ)
• POUT, Stereo Loudspeakers, 8Ω, 3.3V, 1%
THD+N 495mW (typ)
• POUT, Stereo Headphones, 32Ω, 3.3V, 1%
THD+N 33mW (typ)
• POUT, Mono Earpiece, 32Ω, 3.3V, 1% THD+N
43mW (typ)
• Shutdown Current 0.06μA (typ)
APPLICATIONS
• Cell Phones
• PDAs
• Portable Gaming Devices
• Internet Appliances
• Portable DVD/CD/AAC/MP3 players
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 8Ω load, a stereo headphone amplifier delivering
33mW per channel into a 32Ω load, a mono earpiece
amplifier delivering 43mW into a 32Ω load, and a line
output for an external powered handsfree speaker. It
integrates the audio amplifiers, volume control, mixer,
power management control, and TI 3D enhancement
all into a single package. 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 features
include an ultra-low current shutdown mode and
thermal 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 DSBGA
package and a 28–lead UQFN package.
1
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2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2003–2013, Texas Instruments Incorporated