National Semiconductor | High-performance Analog

 

 LM4675   

Ultra-Low EMI, Filterless, 2.65W, Mono, Class D Audio Power Amplifier with Spread Spectrum from the PowerWise® Family
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Features

  • Spread spectrum architecture reduces EMI
  • Mono Class D Operation
  • No output filter required for inductive loads
  • Externally configurable gain
  • Very fast turn on time: 17μs (typ)
  • Minimum external components
  • "Click and pop" suppression circuitry
  • Micro-power shutdown mode
  • Available in space-saving 0.5mm pitch micro SMD and LLP packages
  • Description

    The LM4675 is a single supply, high efficiency, 2.65W, mono, Class D audio amplifier. A spread spectrum, filterless PWM architecture reduces EMI and eliminates the output filter, reducing external component count, board area consumption, system cost, and simplifying design.

    The LM4675 is designed to meet the demands of mobile phones and other portable communication devices. Operating on a single 5V supply, it is capable of driving a 4Ω speaker load at a continuous average output of 2.2W with less than 1% THD+N. Its flexible power supply requirements allow operation from 2.4V to 5.5V. The wide band spread spectrum architecture of the LM4675 reduces EMI-radiated emissions due to the modulator frequency.

    The LM4675 has high efficiency with speaker loads compared to a typical Class AB amplifier. With a 3.6V supply driving an 8Ω speaker, the IC's efficiency for a 100mW power level is 80%, reaching 89% at 400mW output power.

    The LM4675 features a low-power consumption shutdown mode. Shutdown may be enabled by driving the Shutdown pin to a logic low (GND).

    The gain of the LM4675 is externally configurable which allows independent gain control from multiple sources by summing the signals. Output short circuit and thermal overload protection prevent the device from damage during fault conditions.

    Key Specification
    Efficiency at 3.6V, 400mW into 8Ω speaker 89% (typ)
    Efficiency at 3.6V, 100mW into 8Ω speaker 80% (typ)
    Efficiency at 5V, 1W into 8Ω speaker 89% (typ)
    Quiescent current, 3.6V supply 2.2mA (typ)
    Total shutdown power supply current 0.01µA (typ)
    Single supply range 2.4V to 5.5V
    PSRR, f = 217Hz 82dB


    Applications

  • Mobile phones
  • PDAs
  • Portable electronic devices



  •  

    ParametersValues
    Power@ 4Ohms, 1% THD 2.2 Watt
    Power@ 8Ohms, 1% THD 1.3 Watt
    Power@ 4Ohms, 10% THD 2.7 Watt
    Power@ 8Ohms, 10% THD 1.6 Watt
    THD 0.02 %
    PSRR 82 dB
    SNR 97 dB
    Channels 1 Channels
    THD Conditions Vdd=3.6V, Po=0.1W, f=1kHz
    PSRR Conditions 200mVpp 217Hz, 3.6V, Inputs to AC GND, C1=2uF
    SNR Conditions Vdd=5V, Po=1Wrms
    Shut down Yes
    Mono/Stereo Mono
    Shutdown Type High (Audio); Low (LDO)
    Supply Range +1.4 - +3.6 V
    Temperature Min -40 deg C
    Temperature Max 85 deg C
    Automotive Yes
    PowerWise Yes

    Datasheets
    TitleSizeDateOther
    Language
    LM4675 Ultra-Low EMI, Filterless, 2.65W, Mono, Class D Audio Power Amplifier with Spread Spectrum425
    Kbytes
    2-Jul-08   


    Other Technical Documents
    TitleTypeDate
    Class D Amplifier FAQsExternal Article 2008-11-05
    Reducing EMI in Class D Audio Applications by Spread Spectrum Modulation TechniquesExternal Article 2007-01-01

    Part Number(s)
    (NSID)
    Top ViewAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM4675SD/NOPB


    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide3332
    DIGI-KEYWorldwide4236
    MOUSERWorldwide968
    NEWARKAmericas1003
    RSL MICROAsia Pacific10000
    TAYLORAmericas3332
    $0.85 each at 1K+ pcsreel
    of
    1000
    LM4675SDX/NOPB


    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    AVNET-EMWorldwide4500
    DIGI-KEYWorldwide0
    $0.85 each at 1K+ pcsreel
    of
    4500
    LM4675TL/NOPB


    RoHS Status


    MICRO SMD
    Full production
    Lead Time: 8 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide769
    MOUSERWorldwide500
    $0.85 each at 1K+ pcsreel
    of
    250
    LM4675TLX/NOPB


    RoHS Status


    MICRO SMD
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $0.85 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 LM4675.

    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 LM4675 is located at RoHS Status.

    Part Number(s)
    (NSID)
    DescriptionAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM4675SDBD/NOPB

    Ultra-Low EMI, Filterless, 2.65W, Mono, Class D Audio Power Amplifier (LLP-8)Full production
    Lead Free (RoHS)

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $150.00 each1

    The LM4675 is a class D filterless BOOMER audio amplifier with ultra low EMI. National's new spread spectrum technology has been integrated with the latest BOOMER performance characteristics in a 0.5mm pitch, micro SMD package. The LM4675 is designed for high output, low EMI and space saving applications such as mobile phones and other portable communication devices. This all new BOOMER delivers typically 1.3 Watts of power output in 8 ohm load with less than 1% distortion (THD+N) from a 5V DC power supply.

    The LM4675TLBD and LM4675SDBD are evaluation boards designed for rapid user evaluation and saving customers valuable development expense with faster time to market. The evaluation boards include a measurement filter and are ready-to-use in a stand-alone approach that simply requires power and GND, input signal and an output load.

    Features:

    • Tiny 3.0 x 3.0 mm 0.8 mm pitch 8 pin LLP package
    • Very low IDDq (1.6mA at 2.4V)
    • Ultra low EMI suppression of more than 11dB below FCC standard at 6" cable length
    • PSRR 82dB at 217Hz
    • CMRR 80dB at 217Hz
    • SNR 97dB
    • THD+N 0.02% (Pout = 100mW @ 3.6V)

    Applications:

    • Mobile phones
    • PDAs
    • Portable electronic devices and accessories

    Contents:

    • Fully Assembled LM4675 Evaluation Board
    • Instructions for where to locate and download the datasheet

    Please note: application information and board layout can be found in the LM4675 datasheet


    Part Number(s)
    (NSID)
    DescriptionAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM4675TLBD
    Ultra-Low EMI, Filterless, 2.65W, Mono, Class D Audio Power Amplifier (Micro SMD-9)Full production


     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    MOUSERWorldwide1
    $150.00 each1

    The LM4675 is a class D filterless BOOMER audio amplifier with ultra low EMI. National's new spread spectrum technology has been integrated with the latest BOOMER performance characteristics in a 0.5mm pitch, micro SMD package. The LM4675 is designed for high output, low EMI and space saving applications such as mobile phones and other portable communication devices. This all new BOOMER delivers typically 1.3 Watts of power output in 8 ohm load with less than 1% distortion (THD+N) from a 5V DC power supply.

    The LM4675TLBD and LM4675SDBD are evaluation boards designed for rapid user evaluation and saving customers valuable development expense with faster time to market. The evaluation boards include a measurement filter and are ready-to-use in a stand-alone approach that simply requires power and GND, input signal and an output load.

    Features:

    • Tiny 1.514 x 1.514 mm 0.5mm pitch micro SMD package
    • Very low IDDq (1.6mA at 2.4V)
    • Ultra low EMI suppression of more than 11dB below FCC standard at 6" cable length
    • PSRR 82dB at 217Hz
    • CMRR 80dB at 217Hz
    • SNR 97dB
    • THD+N 0.02% (Pout = 100mW @ 3.6V)

    Applications:

    • Mobile phones
    • PDAs
    • Portable electronic devices and accessories

    Contents:

    • Fully Assembled LM4675 Evaluation Board
    • Instructions for where to locate and download the datasheet

    Please note: application information and board layout can be found in the LM4675 datasheet




    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
    LM4675SD/NOPB

    20.736
    LLP81260DetailDownloadN/A
    ZXYTT
    L4675
    LM4675SDX/NOPB

    20.736
    LLP81260DetailDownloadN/A
    ZXYTT
    L4675
    LM4675TL/NOPB

    2.916
    MICRO SMD91260DetailDownloadN/A
    XVG
    I H8
    LM4675TLX/NOPB

    2.916
    MICRO SMD91260DetailDownloadN/A
    XVG
    I H8

    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 LM4675.

    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 LM4675 is located at RoHS Status.

    CAD Symbols and Models
    Download LM4675 CAD Symbols
     Models
    N/A


    Reliability Metrics
    Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
    LM4675SDCMOS70213010015840003449464325
    LM4675SDXCMOS70213010015840003449464325
    LM4675TLCMOS70213010015840003449464325
    LM4675TLXCMOS70213010015840003449464325

    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 LM4675.

    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 LM4675 is located at RoHS Status.

    [Information as of 9-Feb-2012]