National Semiconductor | High-performance Analog

 

 LM25011   

42V, 2A Constant On-Time Switching Regulator with Adjustable Current Limit
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Features

  • LM25011Q is an Automotive Grade product that is AEC-Q100 grade 1 qualified (-40°C to +125°C operating junction temperature)
  • LM25011A allows low dropout operation at high switching frequency
  • Input operating voltage range: 6V to 42V
  • Absolute maximum input rating: 45V
  • Integrated 2A N-Channel Buck Switch
  • Adjustable current limit allows for smaller inductor
  • Adjustable output voltage from 2.51V
  • Minimum ripple voltage at VOUT
  • Power Good output
  • Switching frequency adjustable to 2 MHz
  • COT topology features:

  • -Switching frequency remains nearly constant with load current and input voltage variations

  • -Ultra-fast transient response

  • -No loop compensation required

  • -Stable operation with ceramic output capacitors

  • -Allows for smaller output capacitor and current sense resistor
  • Adjustable Soft-Start timing
  • Thermal shutdown
  • Precision 2% feedback reference
  • Description

    The LM25011 Constant On-time Step-Down Switching Regulator features all the functions needed to implement a low cost, efficient, buck bias regulator capable of supplying up to 2A of load current. This high voltage regulator contains an N-Channel Buck switch, a startup regulator, current limit detection, and internal ripple control. The constant on-time regulation principle requires no loop compensation, results in fast load transient response, and simplifies circuit implementation. The operating frequency remains constant with line and load. The adjustable valley current limit detection results in a smooth transition from constant voltage to constant current mode when current limit is reached, without the use of current limit foldback. The PGD output indicates the output voltage has increased to within 5% of the expected regulation value. Additional features include: Low output ripple, VIN under-voltage lock-out, adjustable soft-start timing, thermal shutdown, gate drive pre-charge, gate drive under-voltage lock-out, and maximum duty cycle limit.

    The LM25011A has a shorter minimum off-time than the LM25011, which allows for higher frequency operation at low input voltages.

    WEBENCH® LM25011
        Min   Max   Range  
      VIN V    6.00 – 42.00V  
      VOUT V    2.51 – 40.00V  
      IOUT A    ≤ 2.00A  
      Ambient Temp °C    ≤ 100°C  
    Footprint BOM Cost Efficiency
    What are WEBENCH® tools?


    Also Recommended
    LM50052.5A, 7-75V Step-down Regulator



    Typical Application
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    Block Diagram
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    Typical Performance
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    Parameters / ValuesLM25011 LM5005
    Output Current2000 mA 2500 mA
    Input Min Voltage6 Volt 7 Volt
    Input Max Voltage42 Volt 75 Volt
    Output Min2.51 Volt 1.23 Volt
    Output Max40 Volt 70 Volt
    Frequency Max2000 kHz 500 kHz
    On/Off PinNo Yes
    PowerGood / Error FlagYes No
    SoftStartYes Yes
    Sync PinNo Yes
    InvertingYes Yes
    FlybackNo No
    RegTypeSwitching Regulator Switching Regulator
    Temperature Min-40 deg C -40 deg C
    Temperature Max125 deg C 125 deg C
    Adjustable OutputYes Yes
    Adj Switch FrequencyYes Yes
    PWM ModeConstant On-Time Current
    TopologyBuck Buck
    Special FeaturesNo compensation req'd, ultra fast transient response, PGD output 1.5% feedback voltage accuracy, emulated current mode
    Step-DownYes Yes
    Multiple Output CapabilityNo No
    Output Range2.51V to 40V 1.23V to 70V
    Feedback Voltage2.51 Volt Undefined Volt
    Regulator FamilySIMPLE SWITCHER
    Synchronous RectificationNo No
    Quiescent Current1.2 mA

    Datasheets
    TitleSizeDateOther
    Language
    LM25011 42V, 2A Constant On-Time Switching Regulator with Adjustable Current Limit458
    Kbytes
    27-Jan-11日本語  


    Application Notes
    TitleSizeDateOther
    Language
    AN-1965: Application Note 1965 LM25011 Evaluation Board378
    Kbytes
    30-May-09 

    Part Number(s)
    (NSID)
    Top ViewAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM25011AQ1MY/NOPB


    RoHS Status


    MINI SOIC EXP PAD
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide1501
    MOUSERWorldwide1000
    $1.55 each at 1K+ pcsreel
    of
    1000
    LM25011AQ1MYX/NOPB


    RoHS Status


    MINI SOIC EXP PAD
    Full production
    Lead Time: 16 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $1.55 each at 1K+ pcsreel
    of
    3500
    LM25011MY/NOPB


    RoHS Status


    MINI SOIC EXP PAD
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    AVNET-EMWorldwide1342
    CEACAsia Pacific3000
    DIGI-KEYWorldwide0
    FARNELLEurope and Asia936
    MOUSERWorldwide1096
    NEWARKAmericas932
    $1.35 each at 1K+ pcsreel
    of
    1000
    LM25011MYX/NOPB


    RoHS Status


    MINI SOIC EXP PAD
    Full production
    Lead Time: 8 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $1.35 each at 1K+ pcsreel
    of
    3500
    LM25011Q1MY/NOPB

    Auto Grade 1
    RoHS Status


    MINI SOIC EXP PAD
    Full production
    Lead Time: 16 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide1272
    MOUSERWorldwide874
    $1.55 each at 1K+ pcsreel
    of
    1000
    LM25011Q1MYX/NOPB

    Auto Grade 1
    RoHS Status


    MINI SOIC EXP PAD
    Full production
    Lead Time: 12 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $1.55 each at 1K+ pcsreel
    of
    3500

    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 LM25011.

    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 LM25011 is located at RoHS Status.

    Part Number(s)
    (NSID)
    DescriptionAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM25011MY-EVAL/NOPB

    Evaluation Board for the LM25011Full production
    Lead Free (RoHS)

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    TAYLORAmericas4
    $30.00 each1

    Description:

    The LM25011EVAL 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 42V. The circuit features an adjustable load current in excess of 2A.

    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
    LM25011AQ1MY/NOPB

    MINI SOIC EXP PAD103260DetailDownloadN/A
    ZXTT
    SZZA
    LM25011AQ1MYX/NOPB

    MINI SOIC EXP PAD103260DetailDownloadN/A
    ZXTT
    SZZA
    LM25011MY/NOPB

    30.155
    MINI SOIC EXP PAD103260DetailDownloadN/A
    ZXTT
    SVUB
    LM25011MYX/NOPB

    30.155
    MINI SOIC EXP PAD103260DetailDownloadN/A
    ZXTT
    SVUB
    LM25011Q1MY/NOPB

    30.155
    MINI SOIC EXP PAD103260DetailDownloadN/A
    ZXTT
    SZFB
    LM25011Q1MYX/NOPB

    30.155
    MINI SOIC EXP PAD103260DetailDownloadN/A
    ZXTT
    SZFB

    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 LM25011.

    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 LM25011 is located at RoHS Status.

    Design Tools
    TitleSizeDate
    LM25011 Quick Start Calculator  

    CAD Symbols and Models
    Download LM25011 CAD Symbols
     Models
    N/A


    Reliability Metrics
    Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
    LM25011AQ1MYABCD5053640016269843461661152
    LM25011AQ1MYXABCD5053640016269843461661152
    LM25011MYABCD5053640016269843461661152
    LM25011MYXABCD5053640016269843461661152
    LM25011Q1MYABCD5053640016269843461661152
    LM25011Q1MYXABCD5053640016269843461661152

    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 LM25011.

    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 LM25011 is located at RoHS Status.

    [Information as of 8-Feb-2012]