National Semiconductor | High-performance Analog

 

 LM20146   

6A, Adjustable Frequency Synchronous Buck Regulator from the PowerWise® Family
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Features

  • Input voltage range 2.95V to 5.5V
  • Accurate current limit minimizes inductor size
  • 97% peak efficiency
  • Adjustable switching frequency (250 kHz to 750 kHz)
  • 16mΩ and 20mΩ integrated FET switches
  • Starts up into pre-biased loads
  • Output voltage tracking
  • Peak current mode control
  • Adjustable output voltage down to 0.8V
  • Adjustable Soft-Start with external capacitor
  • Precision enable pin with hysteresis
  • Integrated OVP, UVLO, power good and thermal shutdown
  • eTSSOP-16 exposed pad package
  • Description

    The LM20146 is a full featured adjustable frequency synchronous buck regulator capable of delivering up to 6A of continuous output current. The current mode control loop can be compensated to be stable with virtually any type of output capacitor. For most cases, compensating the device only requires two external components, providing maximum flexibility and ease of use. The device is optimized to work over the input voltage range of 2.95V to 5.5V making it suitable for a wide variety of low voltage systems.

    The device features internal over voltage protection (OVP) and over current protection (OCP) circuits for increased system reliability. A precision enable pin and integrated UVLO allows the turn-on of the device to be tightly controlled and sequenced. Start-up inrush currents are limited by both an internally fixed and externally adjustable Soft-Start circuit. Fault detection and supply sequencing are possible with the integrated power good circuit.

    The LM20146 is designed to work well in multi-rail power supply architectures. The output voltage of the device can be configured to track a higher voltage rail using the SS/TRK pin. If the output of the LM20146 is pre-biased at startup it will not pull the ouput low.

    The frequency of this device can be adjusted from 250 kHz to 750 kHz by connecting an external resistor from the RT pin to ground.

    The LM20146 is offered in a 16-pin eTSSOP package with an exposed pad that can be soldered to the PCB, eliminating the need for bulky heatsinks.


    Applications

  • Simple to design, high efficiency point of load regulation from a 5V or 3.3V bus
  • High Performance DSPs, FPGAs, ASICs and microprocessors
  • Broadband, Networking and Optical Communications Infrastructure
  • WEBENCH® LM20146
        Min   Max   Range  
      VIN V    2.95 – 5.50V  
      VOUT V    0.80 – 4.00V  
      IOUT A    ≤ 6.00A  
      Ambient Temp °C    ≤ 100°C  
    Footprint BOM Cost Efficiency
    What are WEBENCH® tools?


    Also Recommended
    LM201233A, 1.5 MHz Switching Frequency
    LM201244A, 1 MHz Switching Frequency
    LM201255A, 500 KHz Switching Frequency
    LM201333A, Input Synchronization (500 KHz - 1.5 MHz)
    LM201344A, Input Synchronization (500 KHz - 1.5 MHz)
    LM201366A, Input Synchronization (500 KHz - 1.5 MHz)
    LM201433A, Adjustable Frequency (500 KHz - 1.5 MHz)
    LM201444A, Adjustable Frequency (500 KHz - 1.5 MHz)
    LM201455A, Adjustable Frequency (250 KHz - 750 KHz)
    LM201544A, SYNCOUT



    Parameters / ValuesLM20146 LM20123 LM20124 LM20125 LM20133 LM20134 LM20136 LM20143 LM20144 LM20145 LM20154
    Output Current6000 mA 3000 mA 4000 mA 5000 mA 3000 mA 4000 mA 6000 mA 3000 mA 4000 mA 5000 mA 4000 mA
    Input Min Voltage2.95 Volt 2.95 Volt 2.95 Volt 2.95 Volt 2.95 Volt 2.95 Volt 2.95 Volt 2.95 Volt 2.95 Volt 2.95 Volt 2.95 Volt
    Input Max Voltage5.5 Volt 5.5 Volt 5.5 Volt 5.5 Volt 5.5 Volt 5.5 Volt 5.5 Volt 5.50 Volt 5.5 Volt 5.5 Volt 5.5 Volt
    Output Min0.8 Volt 0.8 Volt 0.8 Volt 0.8 Volt 0.8 Volt 0.8 Volt 0.8 Volt 0.80 Volt 0.8 Volt 0.8 Volt 0.8 Volt
    Output Max5 Volt 5 Volt 5 Volt 5 Volt 5 Volt 5 Volt 5 Volt 5.00 Volt 5 Volt 5 Volt 5 Volt
    Frequency Min250 kHz Undefined kHz Undefined kHz Undefined kHz 460 kHz 460 kHz 500 kHz 510 kHz 500 kHz 250 kHz Undefined kHz
    Frequency Max750 kHz Undefined kHz Undefined kHz Undefined kHz 1500 kHz 1500 kHz 1500 kHz 1500 kHz 1000 kHz 750 kHz Undefined kHz
    Efficiency (peak)97 % 96 % 96 % 96 % 96 % 96 % 97 % 96 % 96 % 97 % 96 %
    Integrated InductorNo No No No No No No No No No No
    PowerGood / Error FlagYes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
    SoftStartYes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
    Sync PinNo No No No Yes Yes Yes No No No No
    InvertingUndefined Undefined Undefined Undefined Undefined Undefined Undefined Undefined Undefined Undefined
    FlybackUndefined Undefined Undefined Undefined Undefined Undefined Undefined Undefined Undefined Undefined
    RegTypeSwitching Regulator Switching Regulator Switching Regulator Switching Regulator Switching Regulator Switching Regulator Switching Regulator Switching Regulator Switching Regulator Switching Regulator Switching Regulator
    Temperature Min-40 deg C -40 deg C -40 deg C -40 deg C -40 deg C -40 deg C -40 deg C -40 deg C -40 deg C -40 deg C -40 deg C
    Temperature Max125 deg C 125 deg C 125 deg C 125 deg C 125 deg C 125 deg C 125 deg C 125 deg C 125 deg C 125 deg C 125 deg C
    Adjustable OutputYes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
    Adj Switch FrequencyYes No No No Yes Yes Yes Yes Yes Yes No
    PWM ModeCurrent Mode Control Current Mode Control Current Mode Control Current Mode Control Current Mode Control Current Mode Control Current Mode Control Current Mode Control Current Mode Control Current Mode Control Current Mode Control
    TopologySynchronous Buck Synchronous Buck Synchronous Buck Synchronous Buck Synchronous Buck Synchronous Buck Synchronous Buck Synchronous Buck Synchronous Buck Synchronous Buck Synchronous Buck
    Special FeaturesDiscontinuous Conduction Mode Undefined Undefined Undefined Undefined Undefined Discontinuous Conduction Mode Undefined Undefined Undefined Sync Output
    Step-DownYes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
    Multiple Output CapabilityNo No No No No No No No No No No
    Output PowerUndefined Watt Undefined Watt Undefined Watt Undefined Watt Undefined Watt Undefined Watt Undefined Watt Undefined Watt Undefined Watt Undefined Watt Undefined Watt
    Output VoltageUndefined Volt Undefined Volt Undefined Volt Undefined Volt Undefined Volt Undefined Volt Undefined Volt Undefined Volt Undefined Volt Undefined Volt Undefined Volt
    Output Range0.8 to 5.0 0.8V to 5.0V 0.8V to 5.0V 0.8V to 5.0V 0.8V to 5.0V 0.8V to 5.0V 0.8V to 5.5V 0.80V to 5.00V 0.8V to 5.0V 0.8V to 5.0V 0.8V to 5.0V
    Switching FrequencyUndefined kHz 1500 kHz 1000 kHz 500 kHz 410 kHz 410 kHz Undefined kHz Undefined kHz Undefined kHz Undefined kHz 1000 kHz
    Feedback Voltage0.8 Volt 0.8 Volt 0.8 Volt 0.8 Volt 0.8 Volt 0.8 Volt 0.8 Volt 0.8 Volt 0.8 Volt 0.8 Volt 0.8 Volt
    On/Off PinYes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
    Regulator FamilyLM20k LM20k LM20k LM20k LM20k LM20k LM20k LM20k LM20k LM20k LM20k
    AEC Q-100 Automotive GradeUndefined Undefined Undefined Undefined Undefined Undefined Undefined 1, 0 1 1 Undefined
    PowerWiseYes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
    Synchronous RectificationYes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
    Quiescent Current3.5 mA 3.5 mA

    Datasheets
    TitleSizeDateOther
    Language
    LM20146 6A, Adjustable Frequency Synchronous Buck Regulator509
    Kbytes
    12-Feb-09日本語  


    Application Notes
    TitleSizeDateOther
    Language
    AN-1902: Application Note 1902 LM20146 Evaluation Board1685
    Kbytes
    19-Jan-09 

    Part Number(s)
    (NSID)
    Top ViewAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM20146MH/NOPB


    RoHS Status


    TSSOP EXP PAD
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide80
    FARNELLEurope and Asia232
    MOUSERWorldwide276
    $1.68 each at 1K+ pcsrail
    of
    92
    LM20146MHE/NOPB


    RoHS Status


    TSSOP EXP PAD
    Full production
    Lead Time: 8 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $1.68 each at 1K+ pcsreel
    of
    250
    LM20146MHX/NOPB


    RoHS Status


    TSSOP EXP PAD
    Full production
    Lead Time: 8 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $1.68 each at 1K+ pcsreel
    of
    2500

    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 LM20146.

    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 LM20146 is located at RoHS Status.

    Part Number(s)
    (NSID)
    DescriptionAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM20146MHEVAL
    6A, Adjustable Frequency Synchronous Buck RegulatorFull production


     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    MOUSERWorldwide1
    $50.00 each1

    Description:

    The LM20146 is a full-featured synchronous buck switching regulator capable of driving up to 6A of load current. The ability to adjust the operating frequency from 250 kHz to 750 kHz gives the designer flexibility in component selection. The LM20146 is capable of converting an input voltage between 2.95V and 5.5V down to an output voltage as low as 0.8V. Fault protection features include cycle-by-cycle current limit, output power good, and output over-voltage protection. The dual function soft-start/tracking pin can be used to control the startup response of the LM20146, and the precision enable pin can be used to easily sequence the LM20146 in sequence-critical applications. The LM20146 is available in an eTSSOP-16 package with an exposed pad for enhanced thermal performance.

    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
    LM20146MH/NOPB

    56.396
    TSSOP EXP PAD161260DetailDownloadN/A
    NSUZXYTT
    L20146
    MH
    LM20146MHE/NOPB

    56.396
    TSSOP EXP PAD161260DetailDownloadN/A
    NSUZXYTT
    L20146
    MH
    LM20146MHX/NOPB

    56.396
    TSSOP EXP PAD161260DetailDownloadN/A
    NSUZXYTT
    L20146
    MH

    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 LM20146.

    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 LM20146 is located at RoHS Status.

    Design Tools
    TitleSizeDate
    Download LM20146 Design Spreadsheet  

    CAD Symbols and Models
    Download LM20146 CAD Symbols
     Models
    N/A


    Reliability Metrics
    Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
    LM20146MHCMOS70213010015840003449464325
    LM20146MHECMOS70213010015840003449464325
    LM20146MHXCMOS70213010015840003449464325

    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 LM20146.

    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 LM20146 is located at RoHS Status.

    What's New in Power -- March 2009
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    LM21212/15 15A Adjustable Current Buck Regulator Overview
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    What's New in Power -- March 2009
    Date: 2009-03-04
    Length: 0:04:07
    LM21212/15 15A Adjustable Current Buck Regulator Overview
    Date: 2011-02-16
    Length: 00:04:50
    [Information as of 9-Feb-2012]