LM4857 - Stereo 1.2W Audio Sub-system with 3D Enhancement

Datasheet	Packaging	Samples & Pricing	Reliability	Knowledge Base

Features

•	Stereo speaker amplifier
•	Stereo headphone amplifier
•	Mono earpiece amplifier
•	Mono Line Output for external handsfree carkit
•	Independent Left, Right, and Mono volume controls
•	National 3D enhancement
•	I²C compatible interface
•	Ultra low shutdown current
•	Click and Pop Suppression circuit
•	16 distinct output modes
•	Thermal Shutdown Protection
•	Available in micro SMD and LLP packages

Key Specification

P_OUT, Stereo Loudspeakers, 4, 5V, 1% THD+N (LM4857SP)	1.6W (typ)
P_OUT, Stereo Loudspeakers, 8, 5V, 1% THD+N	1.2W (typ)
P_OUT, Stereo Headphones, 32, 5V, 1% THD+N	75mW (typ)
P_OUT, Mono Earpiece, 32, 5V, 1% THD+N	100mW (typ)
P_OUT, Stereo Loudspeakers, 8, 3.3V, 1% THD+N	495mW (typ)
P_OUT, Stereo Headphones, 32, 3.3V, 1% THD+N	33mW (typ)
P_OUT, Mono Earpiece, 32, 3.3V, 1% THD+N	43mW (typ)
Shutdown Current	0.06µA (typ)

General Description

The LM4857 is an integrated audio sub-system designed for stereo cell phone applications. More...

Applications

•	Cell Phones
•	PDAs
•	Portable Gaming Devices
•	Internet Appliances
•	Portable DVD/CD/AAC/MP3 players

Typical Application

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Parametric Table expand

Parametric Table collapse

Power@ 4Ohms, 10% THD Undefined Watt

Power@ 4Ohms, 1% THD Undefined Watt

Power@ 8Ohms, 10% THD 1.5 Watt

Power@ 8Ohms, 1% THD 1.2 Watt

THD 0.05 %

PSRR 70 dB

SNR Undefined dB

Channels 6 Channels

THD Conditions Speaker; Po=400mW, 8Ohm BTL

THD Conditions Speaker; Po=400mW, 8Ohm BTL

PSRR Conditions Speaker; Mode 2,3,7,8; Audio inputs terminated

PSRR Conditions Speaker; Mode 2,3,7,8; Audio inputs terminated

Power@ 4Ohms, 10% THD Undefined Watt

Power@ 4Ohms, 1% THD Undefined Watt

Power@ 8Ohms, 10% THD 1.5 Watt

Power@ 8Ohms, 1% THD 1.2 Watt

THD 0.05 %

PSRR 70 dB

SNR Undefined dB

Channels 6 Channels

THD Conditions Speaker; Po=400mW, 8Ohm BTL

PSRR Conditions Speaker; Mode 2,3,7,8; Audio inputs terminated

User Supply 5 Volt

Audio Mux Yes

Capless Headphone No

ClassD Driver No

Interface I2C

Stereo Inputs 1

National 3D Yes

Digital Volume Control Max 6 dB

Digital Volume Control Min -40.5 dB

Output Modes 16

Supply Range +2.7 - +5.5 V

Mono Inputs 1

Temperature Min -40 deg C

Temperature Max 85 deg C

Loudspeaker Type Class AB

Headphone Type Cap Coupled

Loudspeaker Outputs 2

View Using Catalog

Typical Performance

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Connection Diagram

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Datasheet

RoHS Compliance Information	Size in Kbytes	Date
LM4857 Boomer ® Audio Power Amplifier Series Stereo 1.2W Audio Sub-system with 3D Enhancement	1814 Kbytes	8-Jun-05	Download

If you have trouble printing or viewing PDF file(s), see Printing Problems.

Package Availability, Models, Samples & Pricing

Part Number

Package

Factory Lead Time

Models

Samples &
Electronic
Orders

Budgetary Pricing

Std
Pack
Size

Package
Marking
Format

Type

Pins

Spec.

MSL
Rating

Peak
Reflow

RoHS
Report

CAD
Symbols

Weeks

Qty

$US each

LM4857SP

LLP

NOPB

260

RoHS

Download

Full production

N/A

1K+

$2.15

reel
of
1000

NS
UZXYTT
L4857SP

6 weeks

2000

LM4857SPX

N/A

1K+

$2.15

reel
of
4500

NS
UZXYTT
L4857SP

16 weeks

N/A

LM4857ITL

MICRO SMD

NOPB

260

RoHS

Download

Full production

N/A

1K+

$2.00

reel
of
250

XVG
I C2

6 weeks

N/A

LM4857ITLX

MICRO SMD

NOPB

260

RoHS

Download

Full production

N/A

1K+

$2.00

reel
of
3000

XVG
I C2

6 weeks

7500

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM4857GRBD	LM4857ITLBD	NATIONAL SEMICONDUCTOR	16 Nov 2008
LM4857SPX	LM4857ITLX	NATIONAL SEMICONDUCTOR	16 Nov 2008

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 8 load, a stereo headphone amplifier delivering 33mW per channel into a 32 load, a mono earpiece amplifier delivering 43mW into a 32 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 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 ITL package and a 28-lead LLP package.

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM4857ITL	CS065	2	34108	59	0	3862000	1	1095853045
LM4857ITLX	CS065	2	34108	59	0	3862000	1	1095853045
LM4857SP	CS065	2	34108	59	0	3862000	1	1095853045
LM4857SPX	CS065	2	34108	59	0	3862000	1	1095853045

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

For more information on Reliability Metrics, please click here.

[Information as of 3-Jul-2009]