National Semiconductor | High-performance Analog

 

 LM4949   

Stereo Class D Audio Subsystem with OCL Headphone Amplifier
Click link to Download

Features
  • Output Short Circuit Protection
  • Thermal Shutdown
  • Stereo filterless Class D operation
  • Selectable OCL/CC Headphone Drivers
  • RF Suppression
  • I 2C Control Interface
  • 32-step digital volume control
  • Independent Speaker and Headphone Gain Settings
  • Minimum external components
  • Click and Pop suppression
  • Micro-power shutdown
  • Available in space-saving 25 bump µSMD package
  • Description

    The LM4949 is a fully integrated audio subsystem designed for stereo cell phone applications. The LM4949 combines a 2.5W stereo Class D amplifier plus a separate 190mW stereo headphone amplifier, volume control, and input mixer into a single device. The filterless class D amplifiers deliver 1.19W/channel into an 8Ω load with <1% THD+N from a 5V supply. The headphone amplifier features National’s Output Capacitor-less (OCL) architecture that eliminates the output coupling capacitors required by traditional headphone amplifiers. Additionally, the headphone amplifiers can be configured with capacitively coupled (CC)loads, or used to drive an external headphone amplifier. When configured for an external amplifier, the VDD/2 output (VOC) controls the external amplifier’s shutdown input.

    For improved noise immunity, the LM4949 features fully differential left, right and mono inputs. The three inputs can be mixed/multiplexed to either the speaker or headphone amplifiers. The left and right inputs can be used as separate single-ended inputs, mixing multiple stereo audio sources. The mixer, volume control, and device mode select are controlled through an I 2C compatible interface.

    Output short circuit and thermal shutdown protection prevent the device from being damaged during fault conditions. Superior click and pop suppression eliminates audible transients on power-up/down and during shutdown.

    Key Specification
    Efficiency VDD = 3.6V, 400mW into 8Ω 86.5%
    Efficiency VDD = 5V, 1W into 8Ω 87.4%
    Quiescent Power Supply Current @ 3.6V 9.36mA
    Power Output at VDD = 5V  
     Speaker:   RL = 4Ω, THD+N 1%   RL = 8Ω, THD+N 1%   RL = 4Ω, THD+N 10% 2W 1.19W 2.5W
     Headphone:   RL = 16Ω, THD+N 1%   RL = 32Ω, THD+N 1% 153mW 89mW
    Shutdown Current 0.1μA


    Applications

  • Mobile phones
  • PDAs
  • Laptops



  • Typical Application
    click for larger image


    Connection Diagram
    click for larger image



    Typical Performance
    click for larger image


     

    ParametersValues
    Power @ 5V 8Ohms, 1% THD 1.19 Watt
    Speaker THD+N 0.02 %
    HP THD+N 0.01 %
    Speaker PSRR 73 dB
    HP PSRR 75 dB
    Audio Mux Yes
    Audio Mode Control I2C
    Supply Range +2.7 - +5.5 V
    Temperature Min -40 deg C
    Temperature Max 85 deg C
    Mono Analog Inputs 1
    Stereo Analog Inputs 2
    Digital Audio Ports 0
    Loudspeaker Type Class D
    Loudspeaker Outputs 2
    Headphone Type Virtual Ground

    Datasheets
    TitleSizeDateOther
    Language
    LM4949 Stereo Class D Audio Subsystem with OCL Headphone Amplifier984
    Kbytes
    13-Mar-07   


    Application Notes
    TitleSizeDateOther
    Language
    AN-1567: Application Note 1567 LM4949 Demonstration Board3533
    Kbytes
    18-Jul-07 中文

    Part Number(s)
    (NSID)
    Top ViewAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM4949TL/NOPB


    RoHS Status


    MICRO SMD
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide643
    MOUSERWorldwide500
    RS COMPONENTSWorldwide244
    $1.12 each at 1K+ pcsreel
    of
    250
    LM4949TLX/NOPB


    RoHS Status


    MICRO SMD
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $1.12 each at 1K+ pcsreel
    of
    3000

    All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

    Moisture Sensitivity Level Data for LM4949.

    A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

    National's certificate of product compliance for LM4949 is located at RoHS Status.

    Part Number(s)
    (NSID)
    DescriptionAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM4949TLEVAL
    Stereo Class D Audio Subsystem with OCL Headphone AmplifierFull production


     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $325.00 each1

    The LM4949 is an integrated stereo subsystem with filterless stereo Class D speaker amplifiers and selectable output low noise headphone amplifier in a 25-bump micro SMD package. The LM4949 is designed to meet the demands of mobile phones and other portable communication devices. It is capable of delivering 1.19W of average power into stereo 8 ohm loads and 89 milliwatts of average power to a32 ohm load with less than 1% distortion (THD+N) from a 5V DC power supply.

    The LM4949TLEVAL is an evaluation board designed to ease evaluation and effort during the development of a circuit using the LM4949TL. The evaluation board comes with an I2C card and cable. It is an easy-to-use stand-alone board that requires power and GND, an I2C control signal, aninput signal and anoutput load. Software for the product can be downloaded from http://audio.national.com

    Features:

    • Tiny micro SMD
    • Very low iddq (13all outputs on at 5V)
    • High output power (2W into 4ohms at 5V)
    • 73dB PSRR 217Hz for speaker outputs
    • 75dB PSRR 217Hz for headphone outputs
    • 0.02% THD+N at 600mW for speaker outputs
    • 0.02% THD+N at 50mW for OCL headphone outputs

    Applications:

  • Mobile phones
  • Portable devices, such as PMPs, GPS
  • Contents:

    • Fully Assembled LM4949TL Evaluation Board
    • I2C interface card and cable
    • Instructions for where to locate and download the datasheet

    Please note: Go to http://audio.national.com for more information on using the LM4949TL evaluation kit.

    Resources:




    National Semiconductor follows the provisions of the Product Stewardship Guide for Customers (CSP-9-111C1) and Banned Substances and Materials of Interest Specification (CSP-9-111S2) for regulatory environmental compliance. Details may be found at: www.national.com/en/packaging/greennopb.html. Lead free products are RoHS compliant.

    Lead Free product status is available through the search tool located here

    Part Number(s)
    (NSID)
    Weight
    (milligrams)
    TypePinsMSL RatingPeak ReflowRoHS
    Status
    CAD SymbolsModelsPackage
    Marking
    Format
    LM4949TL/NOPB

    8.485
    MICRO SMD251260DetailDownloadN/A
    XYTT
    I GH3
    LM4949TLX/NOPB

    8.485
    MICRO SMD251260DetailDownloadN/A
    XYTT
    I GH3

    All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

    Moisture Sensitivity Level Data for LM4949.

    A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

    National's certificate of product compliance for LM4949 is located at RoHS Status.

    Design Tools
    TitleSizeDate
    Audio Amplifier Digital Control Interface Evaluation Board Software  

    CAD Symbols and Models
    Download LM4949 CAD Symbols
     Models
    N/A


    Reliability Metrics
    Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
    LM4949TLCMOS70213010015840003449464325
    LM4949TLXCMOS70213010015840003449464325

    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.


    All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

    Moisture Sensitivity Level Data for LM4949.

    A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

    National's certificate of product compliance for LM4949 is located at RoHS Status.

    [Information as of 9-Feb-2012]