National Semiconductor | High-performance Analog

 

 LM2842   

600 mA up to 42V Input Step-Down DC/DC Regulator in Thin SOT-23
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Features

  • LM2840Q, LM2841Q and LM2842Q are Automotive Grade products that are AEC-Q100 grade 1 qualified (-40°C to +125°C operating junction temperature)
  • Input voltage range of 4.5V to 42V
  • Output current options of 100 mA, 300 mA and 600 mA
  • Feedback pin voltage of 0.765V
  • 550 kHz (X) or 1.25 MHz (Y) switching frequency
  • Low shutdown IQ, 16 µA typical
  • Short circuit protected
  • Internally compensated
  • Soft-start circuitry
  • Small overall solution size (TSOT-6L package)
  • Description

    The LM2840, LM2841 and LM2842 are PWM DC/DC buck (step-down) regulators. With a wide input range from 4.5V-42V, they are suitable for a wide range of applications such as power conditioning from unregulated sources. They feature a low RDSON (0.9Ω typical) internal switch for maximum efficiency (85% typical). Operating frequency is fixed at 550 kHz (X version) and 1.25 MHz (Y version) allowing the use of small external components while still being able to have low output voltage ripple. Soft-start can be implemented using the shutdown pin with an external RC circuit allowing the user to tailor the soft-start time to a specific application.

    The LM2840 is optimized for up to 100 mA, the LM2841 for 300 mA and the LM2842 is optimized for up to 600 mA load currents. They all have a 0.765V nominal feedback voltage.

    Additional features include: thermal shutdown, VIN under-voltage lockout, and gate drive under-voltage lockout. The LM2840, LM2841 and LM2842 are available in a low profile TSOT-6L package.


    Applications

  • Battery powered equipment
  • Industrial distributed power applications
  • Portable media players
  • Portable hand held instruments
  • WEBENCH® LM2842X
        Min   Max   Range  
      Vin V    4.50 – 42.00V  
      Vout V    0.77 – 40.00V  
      Iout A    ≤ 0.60A  
      Ambient Temp °C    ≤ 100°C  
    Footprint BOM Cost Efficiency
     
     
     
     
    What are WEBENCH® tools?



    front page schematic, no component values

     

    ParametersValues
    Output Current 600 mA
    Input Min Voltage 4.5 Volt
    Input Max Voltage 42 Volt
    Output Min 0.765 Volt
    Output Max 34 Volt
    Frequency Min 550 kHz
    Frequency Max 1250 kHz
    Efficiency (peak) 85 %
    On/Off Pin Yes
    PowerGood / Error Flag No
    SoftStart Yes
    Sync Pin No
    Inverting No
    Flyback No
    RegType Switching Regulator
    Temperature Min -40 deg C
    Temperature Max 125 deg C
    Adjustable Output Yes
    Adj Switch Frequency No
    PWM Mode current-mode
    Topology buck
    Special Features internal compensation
    Step-Down Yes
    Multiple Output Capability No
    Quiescent Current .016 mA

    Datasheets
    TitleSizeDateOther
    Language
    LM2842 600 mA up to 42V Input Step-Down DC/DC Regulator in Thin SOT-23326
    Kbytes
    23-Aug-11   


    Application Notes
    TitleSizeDateOther
    Language
    AN-1908: Application Note 1908 LM2842 Evaluation Board427
    Kbytes
    2-Sep-09 
    AN-1982: Application Note 1982 Small, Wide Input Voltage Range LM2842 Keeps LEDs Cool63
    Kbytes
    15-Jul-09 

    Part Number(s)
    (NSID)
    Top ViewAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM2842XMK-ADJL/NOPB


    RoHS Status


    TSOT
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide1494
    AVNET-EMWorldwide1819
    DIGI-KEYWorldwide3764
    FARNELLEurope and Asia158
    MOUSERWorldwide448
    NEWARKAmericas148
    RSL MICROAsia Pacific4000
    TAYLORAmericas1494
    $1.44 each at 1K+ pcsreel
    of
    1000
    LM2842XMKX-ADJL/NOPB


    RoHS Status


    TSOT
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $1.44 each at 1K+ pcsreel
    of
    3000
    LM2842XQMK/NOPB


    RoHS Status


    TSOT
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide1864
    MOUSERWorldwide845
    $1.64 each at 1K+ pcsreel
    of
    1000
    LM2842XQMKX/NOPB


    RoHS Status


    TSOT
    Full production
    Lead Time: 8 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $1.64 each at 1K+ pcsreel
    of
    3000
    LM2842YMK-ADJL/NOPB


    RoHS Status


    TSOT
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide27000
    AVNET-EMWorldwide1027
    DIGI-KEYWorldwide3842
    FARNELLEurope and Asia984
    MOUSERWorldwide543
    NEWARKAmericas992
    TAYLORAmericas27000
    $1.49 each at 1K+ pcsreel
    of
    1000
    LM2842YMKX-ADJL/NOPB


    RoHS Status


    TSOT
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $1.49 each at 1K+ pcsreel
    of
    3000
    LM2842YQMK/NOPB


    RoHS Status


    TSOT
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide1598
    MOUSERWorldwide995
    $1.64 each at 1K+ pcsreel
    of
    1000
    LM2842YQMKX/NOPB


    RoHS Status


    TSOT
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $1.64 each at 1K+ pcsreel
    of
    3000

    Obsolete Versions
    Obsolete PartAlternate Part or SupplierSourceLast Time Buy Date
    LM2842XMK-ADJ
    NONE
    NONE
    30 Nov 2009
    LM2842XMKX-ADJ
    NONE
    NONE
    30 Nov 2009

    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 LM2842.

    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 LM2842 is located at RoHS Status.

    Part Number(s)
    (NSID)
    DescriptionAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM2842XMK-ADJEV/NOPB

    Evaluation Board for the LM2842Full production
    Lead Free (RoHS)

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    FARNELLEurope and Asia1
    MOUSERWorldwide2
    NEWARKAmericas1
    $55.60 each1

    Description:

    The LM2842 evaluation board is designed to provide the design engineer with a fully functional power converter based on the buck topology to evaluate the LM2842 series of buck regulators. The evaluation board comes populated with the LM2842XMK-ADJL but can easily be modified to accommodate any of the LM2842 regulator ICs.

    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
    LM2842XMK-ADJL/NOPB

    13.726
    13.851
    TSOT61260DetailDownloadN/A
    STVB
    XTT
    LM2842XMKX-ADJL/NOPB

    13.726
    13.851
    TSOT61260DetailDownloadN/A
    STVB
    XTT
    LM2842XQMK/NOPB

    TSOT61260DetailDownloadN/A
    SB3B
    XTT
    LM2842XQMKX/NOPB

    TSOT61260DetailDownloadN/A
    SB3B
    XTT
    LM2842YMK-ADJL/NOPB

    13.726
    13.851
    TSOT61260DetailDownloadN/A
    STXB
    XTT
    LM2842YMKX-ADJL/NOPB

    13.726
    13.851
    TSOT61260DetailDownloadN/A
    STXB
    XTT
    LM2842YQMK/NOPB

    TSOT61260DetailDownloadN/A
    SB4B
    XTT
    LM2842YQMKX/NOPB

    TSOT61260DetailDownloadN/A
    SB4B
    XTT

    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 LM2842.

    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 LM2842 is located at RoHS Status.

    Reliability Metrics
    Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
    LM2842XMK-ADJLABCD5053640016269843461661152
    LM2842XMKX-ADJLABCD5053640016269843461661152
    LM2842XQMKABCD5053640016269843461661152
    LM2842XQMKXABCD5053640016269843461661152
    LM2842YMK-ADJLABCD5053640016269843461661152
    LM2842YMKX-ADJLABCD5053640016269843461661152
    LM2842YQMKABCD5053640016269843461661152
    LM2842YQMKXABCD5053640016269843461661152

    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 LM2842.

    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 LM2842 is located at RoHS Status.

    Obsolete Versions
    Obsolete PartAlternate Part or SupplierSourceLast Time Buy Date
    LM2842XMK-ADJ
    NONE
    NONE
    30 Nov 2009
    LM2842XMKX-ADJ
    NONE
    NONE
    30 Nov 2009

    Power for Space-Constrained Applications
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    Power for Space-Constrained Applications
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    LED Bulb Replacement Using National LED Drivers & Nuventix SynJet® Coolers
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    Power for Space-Constrained Applications
    Date: 2009-04-22
    Length: 0:03:35
    Power for Space-Constrained Applications
    Date: 2009-04-22
    Length: 00:45:00
    LED Bulb Replacement Using National LED Drivers & Nuventix SynJet® Coolers
    Date: 2009-06-18
    Length: 0:18:34
    [Information as of 3-Feb-2012]