National Semiconductor | High-performance Analog

 

 LM22679   

5A SIMPLE SWITCHER®, Step-Down Voltage Regulator with Adjustable Soft-Start and Current Limit
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Features

  • Wide input voltage range: 4.5V to 42V
  • Internally compensated voltage mode control
  • Stable with low ESR ceramic capacitors
  • 100 mΩ N-channel MOSFET
  • Output voltage options:

  •  -ADJ (outputs as low as 1.285V)

  •  -5.0 (output fixed to 5V)
  • ±1.5% feedback reference accuracy
  • Switching frequency of 500kHz
  • -40°C to 125°C operating junction temperature range
  • Adjustable soft-start
  • Adjustable current limit
  • Integrated boot diode
  • Fully WEBENCH ® enabled
  • Step-down and inverting buck-boost applications
  • Description

    The LM22679 series of regulators are monolithic integrated circuits which provide all of the active functions for a step-down (buck) switching regulator capable of driving up to 5A loads with excellent line and load regulation characteristics. High efficiency (>90%) is obtained through the use of a low ON-resistance N-channel MOSFET. The series consists of a fixed 5V output and an adjustable version.

    The SIMPLE SWITCHER ® concept provides for an easy to use complete design using a minimum number of external components and National’s WEBENCH ® design tool. National’s WEBENCH ® tool includes features such as external component calculation, electrical simulation, thermal simulation, and Build-It boards for easy design-in. The switching clock frequency is provided by an internal fixed frequency oscillator which operates at 500 kHz. The LM22679 series also has built in thermal shutdown and current limiting. The current limit threshold can be adjusted using an external resistor. An adjustable soft-start feature is provided by selecting an appropriate external soft-start capacitor.


    Applications

  • Industrial Control
  • Telecom and Datacom Systems
  • Embedded Systems
  • Automotive Telematics and Body Electronics
  • Conversions from Standard 24V, 12V and 5V Input Rails
  • WEBENCH® LM22679
        Min   Max   Range  
      VIN V    4.50 – 42.00V  
      VOUT V    1.28 – 37.00V  
      IOUT A    ≤ 5.00A  
      Ambient Temp °C    ≤ 100°C  
    Footprint BOM Cost Efficiency
    What are WEBENCH® tools?


    Also Recommended
    LM226710.5A Version
    LM226721A Version
    LM226733A Version
    LM22677Features Adjustable Switching Frequency And Frequency Sync Up 1MHz And Precision Enable
    LM22678Features Precision Enable
    LM226802A Version
    LM3150Synchronous Simple Switcher Controller For Higher Efficiency



    Typical Application
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    Connection Diagram
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    Typical Performance
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    Parameters / ValuesLM22679 LM22671 LM22672 LM22673 LM22677 LM22678 LM22680 LM3150
    Output Current5000 mA 500 mA 1000 mA 3000 mA 5000 mA 5000 mA 2000 mA 12000 mA
    Input Min Voltage4.5 Volt 4.5 Volt 4.5 Volt 4.5 Volt 4.5 Volt 4.5 Volt 4.5 Volt 6 Volt
    Input Max Voltage42 Volt 42 Volt 42 Volt 42 Volt 42 Volt 42 Volt 42 Volt 42 Volt
    Output Min1.285 Volt 1.285 Volt 1.285 Volt 1.285 Volt 1.285 Volt 1.285 Volt 1.285 Volt
    Efficiency (peak)92 % 91 % 92 % 92 % 92 % 92 % 89 % 95 %
    On/Off PinNo Yes Yes No Yes Yes Yes Yes
    PowerGood / Error FlagNo No No No No No No No
    SoftStartYes Yes Yes Yes No No Yes Yes
    Sync PinNo Yes Yes No Yes No Yes No
    InvertingYes Yes Yes Yes Yes Yes No
    FlybackNo No No No No No No No
    RegTypeSwitching Regulator Switching Regulator Switching Regulator Switching Regulator Switching Regulator Switching Regulator Switching Regulator Switching Controller
    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
    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
    Adjustable OutputYes Yes Yes Yes Yes Yes Yes Yes
    Adj Switch FrequencyNo Yes Yes No Yes No Yes Yes
    PWM ModeVoltage Mode Control Voltage Mode Control Voltage Mode Control Voltage Mode Control Voltage Mode Control Voltage Mode Control Voltage Mode Control
    TopologyBuck Buck Buck Buck Buck Buck Buck Step-Down/Buck
    Special FeaturesAdjustable Current Limit 500 kHz Default Switching Fequency 500 kHz Default Switching Frequency Adjustable Current Limit 500 kHz Default Switching Frequency 500 kHz Switching Frequency
    Step-DownYes Yes Yes Yes Yes Yes Yes Yes
    Multiple Output CapabilityNo No No No No No No No
    Switching Frequency500 kHz 500 kHz 500 kHz 500 kHz 500 kHz 500 kHz 500 kHz
    Feedback Voltage1.285 Volt 1.285 Volt 1.285 Volt 1.285 Volt 1.285 Volt 1.285 Volt 1.285 Volt 0.6 Volt
    Regulator FamilySIMPLE SWITCHER SIMPLE SWITCHER SIMPLE SWITCHER SIMPLE SWITCHER SIMPLE SWITCHER SIMPLE SWITCHER SIMPLE SWITCHER SIMPLE SWITCHER
    AutomotiveNo No No No No No
    PowerWiseNo No No No No No No Yes
    Synchronous RectificationNo No No No No No No Yes

    Datasheets
    TitleSizeDateOther
    Language
    LM22679 5A SIMPLE SWITCHER®, Step-Down Voltage Regulator with Adjustable Soft-Start and Current Limit375
    Kbytes
    22-Oct-10日本語
    中文


    Application Notes
    TitleSizeDateOther
    Language
    AN-1889: Application Note 1889 How to Measure the Loop Transfer Function of Power Supplies612
    Kbytes
    14-Oct-08 
    AN-1930: Application Note 1930 SIMPLE SWITCHER® Regulators Take Over Automotive Applications85
    Kbytes
    7-Jan-09 
    AN-1891: Application Note 1891 LM22679 Evaluation Board183
    Kbytes
    12-Mar-10 


    Other Technical Documents
    TitleTypeDate
    SIMPLE SWITCHER® Design GuideDesign Guide 2011-04-11

    Part Number(s)
    (NSID)
    Top ViewAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM22679TJ-5.0/NOPB


    RoHS Status


    TO-263 THIN
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    AVNET-EMWorldwide1000
    DIGI-KEYWorldwide0
    MOUSERWorldwide1000
    $3.38 each at 1K+ pcsreel
    of
    1000
    LM22679TJ-ADJ/NOPB


    RoHS Status


    TO-263 THIN
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    FARNELLEurope and Asia429
    MOUSERWorldwide1890
    $3.38 each at 1K+ pcsreel
    of
    1000
    LM22679TJE-5.0/NOPB


    RoHS Status


    TO-263 THIN
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    AVNET-EMWorldwide250
    DIGI-KEYWorldwide524
    MOUSERWorldwide150
    NEWARKAmericas18
    $3.38 each at 1K+ pcsreel
    of
    250
    LM22679TJE-ADJ/NOPB


    RoHS Status


    TO-263 THIN
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide200
    AVNET-EMWorldwide250
    DIGI-KEYWorldwide2624
    FARNELLEurope and Asia168
    MOUSERWorldwide149
    NEWARKAmericas736
    TAYLORAmericas200
    $3.38 each at 1K+ pcsreel
    of
    250

    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 LM22679.

    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 LM22679 is located at RoHS Status.

    Part Number(s)
    (NSID)
    DescriptionAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM22679EVAL/NOPB

    Evaluation Board for LM22679, 5A Adjustable Output Voltage Evaluation Board Features: Adjustable Soft-Start, and Adjustable Switching FrequencyFull production
    Lead Free (RoHS)

     
    DistributorRegionQty
    ARROWWorldwide14
    DIGI-KEYWorldwide11
    TAYLORAmericas19
    $24.00 each1

    Description:

    The LM22679 evaluation board is designed to demonstrate the capabilities of the LM22679 switching regulator. The LM22679 evaluation board is configured to provide an output voltage of 3.3V up to 5A load current with an input voltage range of 4.5V to 42V. Due to the low RDS(ON) of the integrated N-channel MOSFET and maximum duty-cycle limitations, the minimum input voltage of 4.5V will only provide a 3.3V output voltage for load currents up to 500 mA. At 5.5V input voltage 3A of output current is possible while maintaining 3.3V of output voltage. For load currents higher than 3A, in input voltage of 6.5V or higher is required. The typical operating frequency is 500 kHz. The evaluation board is designed to operate at ambient temperatures up to 30 °C.

    Features:

    • Input Range: 4.5V to 42V
    • Output Voltage: 3.3V
    • Output Current Range: 0A to 5A
    • Frequency of Operation: 500 kHz
    • Board Size: 2 X 2 inches
    • Package: TO-263 THIN

    At low input voltages between 4.5V and 6V, a minimum load of approximately 5 mA may be required to reach a regulated 3.3V output voltage. To aid in the design and evaluation of DC/DC buck converter solutions based on the LM22679 switching regulator, the evaluation board can be re-configured for different output voltages.

    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
    LM22679TJ-5.0/NOPB

    790.208
    TO-263 THIN71260DetailDownloadN/A
    NSUZXYTTE#
    LM22679
    TJ-5.0
    LM22679TJ-ADJ/NOPB

    790.208
    TO-263 THIN71260DetailDownloadN/A
    NSUZXYTTE#
    LM22679
    TJ-ADJ
    LM22679TJE-5.0/NOPB

    790.208
    TO-263 THIN71260DetailDownloadN/A
    NSUZXYTTE#
    LM22679
    TJ-5.0
    LM22679TJE-ADJ/NOPB

    790.208
    TO-263 THIN71260DetailDownloadN/A
    NSUZXYTTE#
    LM22679
    TJ-ADJ

    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 LM22679.

    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 LM22679 is located at RoHS Status.

    Reliability Metrics
    Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
    LM22679TJ-5.0ABCD5053640016269843461661152
    LM22679TJ-ADJABCD5053640016269843461661152
    LM22679TJE-5.0ABCD5053640016269843461661152
    LM22679TJE-ADJABCD5053640016269843461661152

    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 LM22679.

    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 LM22679 is located at RoHS Status.

    5th Generation SIMPLE SWITCHER® Regulator Family Technical Overview
    Click image to play video in new window


    5th Generation SIMPLE SWITCHER® Regulator Family Technical Overview
    Date: 2009-03-11
    Length: 0:21:05
    [Information as of 7-Feb-2012]