National Semiconductor | High-performance Analog

 

 LM3481   

High Efficiency Low-Side N-Channel Controller for Switching Regulators
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Features

  • LM3481QMM in the MSOP-10 package are Automotive Grade products that are AEC-Q100 grade 1 qualified (-40°C to +125°C operating junction temperature)
  • 10-lead MSOP package
  • Internal push-pull driver with 1A peak current capability
  • Current limit and thermal shutdown
  • Frequency compensation optimized with a capacitor and a resistor
  • Internal softstart
  • Current Mode Operation
  • Adjustable Undervoltage Lockout with Hysteresis
  • Pulse Skipping at Light Loads
  • Description

    The LM3481 is a versatile Low-Side N-FET high performance controller for switching regulators. It is suitable for use in topologies requiring a low-side FET, such as boost, flyback, SEPIC, etc. The LM3481 can be operated at extremely high switching frequencies in order to reduce the overall solution size. The switching frequency of the LM3481 can be adjusted to any value between 100 kHz and 1 MHz by using a single external resistor or by synchronizing it to an external clock. Current mode control provides superior bandwidth and transient response in addition to cycle-by-cycle current limiting. Current limit can be programmed with a single external resistor.

    The LM3481 has built in protection features such as thermal shutdown, short-circuit protection and over voltage protection. Power saving shutdown mode reduces the total supply current to 5µA and allows power supply sequencing. Internal soft-start limits the inrush current at start-up.

    Key Specification

  • Wide supply voltage range of 2.97V to 48V
  • 100 kHz to 1 MHz Adjustable and Synchronizable clock frequency
  • ±1.5% (over temperature) internal reference
  • 10 µA shutdown current (over temperature)

  • Applications

  • Distributed Power Systems
  • Notebook, PDA, Digital Camera, and other Portable Applications
  • Offline Power Supplies
  • Set-Top Boxes
  • WEBENCH® LM3481
        Min   Max   Range  
      VIN V    2.97 – 48.00V  
      VOUT V    1.26 – 300.00V  
      IOUT A    ≤ 10.00A  
      Ambient Temp °C    ≤ 100°C  
    Footprint BOM Cost Efficiency
    What are WEBENCH® tools?





    Typical Application
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    Block Diagram
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    Typical Performance
    *click for larger image


     

    ParametersValues
    Input Min Voltage 2.97 Volt
    Input Max Voltage 48 Volt
    Adjustable Output Yes
    Feedback Voltage 1.275 Volt
    Output Range 1.275V min
    Frequency Min 100 kHz
    Frequency Max 1000 kHz
    Adj Switch Frequency Yes
    Sync Pin Yes
    On/Off Pin Yes
    SoftStart Yes
    PowerGood / Error Flag No
    Special Features Adjustable UVLO
    Topology Boost, SEPIC, Flyback
    Step-Down No
    Step-Up Yes
    Inverting No
    Flyback Yes
    RegType Switching Controller
    Multiple Output Capability Yes
    Temperature Min -40 deg C
    Temperature Max 125 deg C
    Automotive Yes

    Datasheets
    TitleSizeDateOther
    Language
    LM3481 High Efficiency Low-Side N-Channel Controller for Switching Regulators477
    Kbytes
    15-Mar-11日本語  


    Application Notes
    TitleSizeDateOther
    Language
    AN-1756: Application Note 1756 LM3481 Evaluation Board505
    Kbytes
    30-Apr-08日本語
    AN-2094: Application Note 2094 LM3481 SEPIC Evaluation Board891
    Kbytes
    14-Sep-11 

    Part Number(s)
    (NSID)
    Top ViewAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM3481MM/NOPB


    RoHS Status


    MINI SOIC
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide1000
    AVNET-EMWorldwide843
    DIGI-KEYWorldwide340
    FARNELLEurope and Asia556
    MOUSERWorldwide822
    NEWARKAmericas360
    TAYLORAmericas1000
    $0.95 each at 1K+ pcsreel
    of
    1000
    LM3481MMX/NOPB


    RoHS Status


    MINI SOIC
    Full production
    Lead Time: 8 weeks

     
    DistributorRegionQty
    AVNET-EMWorldwide3500
    DIGI-KEYWorldwide0
    $0.95 each at 1K+ pcsreel
    of
    3500
    LM3481QMM/NOPB


    RoHS Status


    MINI SOIC
    Full production
    Lead Time: 8 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide2241
    MOUSERWorldwide1000
    $1.15 each at 1K+ pcsreel
    of
    1000
    LM3481QMMX/NOPB


    RoHS Status


    MINI SOIC
    Full production
    Lead Time: 8 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $1.15 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 LM3481.

    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 LM3481 is located at RoHS Status.

    Part Number(s)
    (NSID)
    DescriptionAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM3481EVAL/NOPB

    High Efficiency Boost Switching Controller Eval Board with 12 Volt OutputFull production
    Lead Free (RoHS)

     
    DistributorRegionQty
    AVNET-EMWorldwide2
    DIGI-KEYWorldwide0
    MOUSERWorldwide4
    $85.00 each1

    Description:

    The LM3481 is a current mode, low side N channel FET controller. It can be utilized in numerous configurations including a Boost, Flyback or SEPIC (Single Ended Primary Inductor Converter). This evaluation board demonstrates the flexibility of the LM3481 in a boost topology providing 12 volt output at 1.5 amps.

    Contents:


    Part Number(s)
    (NSID)
    DescriptionAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM3481SEPICEVAL
    evaluation boardFull production


     

    Contact your distributor
    CALLN/A



    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
    LM3481MM/NOPB

    29.841
    MINI SOIC101260DetailDownloadN/A
    ZXTT
    SJPB
    LM3481MMX/NOPB

    29.841
    MINI SOIC101260DetailDownloadN/A
    ZXTT
    SJPB
    LM3481QMM/NOPB

    MINI SOIC101260DetailDownloadN/A
    ZXTT
    SUAB
    LM3481QMMX/NOPB

    MINI SOIC101260DetailDownloadN/A
    ZXTT
    SUAB

    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 LM3481.

    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 LM3481 is located at RoHS Status.

    Reliability Metrics
    Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
    LM3481MMABCD5053640016269843461661152
    LM3481MMXABCD5053640016269843461661152
    LM3481QMMABCD5053640016269843461661152
    LM3481QMMXABCD5053640016269843461661152

    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 LM3481.

    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 LM3481 is located at RoHS Status.

    SEPIC Converter Circuit Basics
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    SEPIC Converter Circuit Basics
    Date: 2010-03-02
    Length: 0:07:01
    [Information as of 8-Feb-2012]