National Semiconductor | High-performance Analog

 

 LM5008A   

100V, 350 mA Constant On-Time Buck Switching Regulator
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Features

  • Operating input voltage range: 6V to 95V
  • Integrated 100V, N-Channel buck switch
  • Internal start-up regulator
  • No loop compensation required
  • Ultra-Fast transient response
  • On time varies inversely with input voltage
  • Operating frequency remains constant with varying line voltage and load current
  • Adjustable output voltage from 2.5V
  • Highly efficient operation
  • Precision internal reference
  • Low bias current
  • Intelligent current limit
  • Thermal shutdown
  • Description

    The LM5008A is a functional variant of the LM5008 COT Buck Switching Regulator. The functional differences of the LM5008A are: The minimum input operating voltage is 6 volts, the on-time equation is slightly different, and the requirement for a minimum load current is removed.

    The LM5008A Step Down Switching Regulator features all of the functions needed to implement a low cost, efficient, Buck bias regulator. This high voltage regulator contains an 100 V N-Channel Buck Switch. The device is easy to implement and is provided in the MSOP-8 and the thermally enhanced LLP-8 packages. The regulator is based on a control scheme using an ON time inversely proportional to VIN. This feature allows the operating frequency to remain relatively constant. The control scheme requires no loop compensation. An intelligent current limit is implemented with forced OFF time, which is inversely proportional to Vout. This scheme ensures short circuit control while providing minimum foldback. Other features include: Thermal Shutdown, VCC under-voltage lockout, Gate drive under-voltage lockout, Max Duty Cycle limiter, and a pre-charge switch.

    Also Recommended
    LM5007500mA Output Current, 9-75V Input Range Step-down Switching Regulator
    LM5010A1A Ouput Current; 6-75V Input Range Step-down Switching Regulator



    Typical Application
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    Block Diagram
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    Typical Performance
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    Parameters / ValuesLM5008A LM5007 LM5010A
    Output Current350 mA 500 mA 1000 mA
    Input Min Voltage6 Volt 9 Volt 6 Volt
    Input Max Voltage95 Volt 75 Volt 75 Volt
    Output Min2.5 Volt 2.5 Volt 2.5 Volt
    Output Max75 Volt 73 Volt 70 Volt
    Frequency Min50 kHz 50 kHz 50 kHz
    Frequency Max600 kHz 800 kHz 1000 kHz
    Efficiency (peak)92 % 93 % 95 %
    On/Off PinYes Yes Yes
    PowerGood / Error FlagNo No No
    SoftStartNo No Yes
    Sync PinNo No No
    InvertingYes Yes Yes
    FlybackNo No No
    RegTypeSwitching Regulator Switching Regulator Switching Regulator
    Temperature Min-40 deg C -40 deg C -40 deg C
    Temperature Max125 deg C 125 deg C 150 deg C
    Adjustable OutputYes Yes Yes
    Adj Switch FrequencyYes Yes Yes
    PWM ModeConstant On-Time Constant on-time Constant on-time
    TopologyBuck Buck Buck
    Special FeaturesInternal Startup regulator Internal startup regulator for Vin>9V, internal 80V/0.7A N-FET, Pull Ron pin to ground for shutdown No compensation required, ultra-fast transient response
    Step-DownYes Yes Yes
    Multiple Output CapabilityNo No No
    Output Range2.5V to 75V 2.5V to 73V 2.5V to 70V
    Switching Frequency600 kHz 800 kHz 1000 kHz
    Feedback Voltage2.5 Volt 2.5 Volt 2.5 Volt
    Synchronous RectificationNo No No
    Quiescent Current0.55 mA

    Datasheets
    TitleSizeDateOther
    Language
    LM5008A 100V, 350 mA Constant On-Time Buck Switching Regulator400
    Kbytes
    21-Apr-11   


    Application Notes
    TitleSizeDateOther
    Language
    AN-1925: Application Note 1925 LM5008A Evaluation Board439
    Kbytes
    25-Mar-10 

    Part Number(s)
    (NSID)
    Top ViewAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM5008AMM/NOPB


    RoHS Status


    MINI SOIC
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide1000
    AVNET-EMWorldwide824
    DIGI-KEYWorldwide2671
    FARNELLEurope and Asia131
    MOUSERWorldwide866
    NEWARKAmericas131
    TAYLORAmericas1000
    $1.45 each at 1K+ pcsreel
    of
    1000
    LM5008AMMX/NOPB


    RoHS Status


    MINI SOIC
    Full production
    Lead Time: 16 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $1.45 each at 1K+ pcsreel
    of
    3500
    LM5008ASD/NOPB


    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    AVNET-EMWorldwide343
    DIGI-KEYWorldwide11641
    FARNELLEurope and Asia837
    NEWARKAmericas837
    $1.45 each at 1K+ pcsreel
    of
    1000
    LM5008ASDX/NOPB


    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $1.45 each at 1K+ pcsreel
    of
    4500

    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 LM5008A.

    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 LM5008A is located at RoHS Status.

    Part Number(s)
    (NSID)
    DescriptionAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM5008AEVAL/NOPB

    Evaluation Board for the LM5008AFull production
    Lead Free (RoHS)

     
    DistributorRegionQty
    AVNET-EMWorldwide3
    DIGI-KEYWorldwide5
    MOUSERWorldwide1
    $52.00 each1

    Description:

    The LM5008AEVAL evaluation board provides the design engineer with a fully functional buck regulator, employing the constant on-time (COT) operating principle. This evaluation board provides a 5V output over an input range of 8V to 75V. The circuit delivers load currents to 300 mA, with current limit set at a nominal 440 mA.

    Contents:




    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
    LM5008AMM/NOPB

    29.851
    MINI SOIC81260DetailDownloadN/A
    ZXTT
    SAYA
    LM5008AMMX/NOPB

    29.851
    MINI SOIC81260DetailDownloadN/A
    ZXTT
    SAYA
    LM5008ASD/NOPB

    37.567
    LLP81260DetailDownloadN/A
    NS
    UZXYTT
    L00070A
    LM5008ASDX/NOPB

    37.567
    LLP81260DetailDownloadN/A
    NS
    UZXYTT
    L00070A

    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 LM5008A.

    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 LM5008A is located at RoHS Status.

    Design Tools
    TitleSizeDate
    LM5008A Quick Start Calculator  

    CAD Symbols and Models
    Download LM5008A CAD Symbols
     Models
    N/A


    Reliability Metrics
    Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
    LM5008AMMABCD150XV2036010011554964327875145
    LM5008AMMXABCD150XV2036010011554964327875145
    LM5008ASDABCD150XV2036010011554964327875145
    LM5008ASDXABCD150XV2036010011554964327875145

    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 LM5008A.

    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 LM5008A is located at RoHS Status.

    [Information as of 9-Feb-2012]