National Semiconductor | High-performance Analog

 

 LM3676   

2MHz, 600mA Step-Down DC-DC Converter with Mode Control
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Features
  • 16 µA typical quiescent current
  • 600 mA maximum load capability
  • 2 MHz PWM fixed switching frequency (typ)
  • Automatic PFM/PWM mode switching or Forced PWM mode
  • Available in fixed output voltages and adjustable version
  • 8-Lead non-pullback LLP package
  • Internal synchronous rectification for high efficiency
  • Internal soft start
  • 0.01 µA typical shutdown current
  • Operates from a single Li-Ion cell battery
  • Only three tiny surface-mount external components required (one inductor, two ceramic capacitors)
  • Current overload and Thermal shutdown protection
  • Description

    The LM3676 step-down DC-DC converter is optimized for powering low voltage circuits from a single Li-Ion cell battery and input voltage rails from 2.9V to 5.5V. It provides up to 600mA load current, over the entire input voltage range. There are several different fixed voltage output options available as well as an adjustable output voltage version.

    The LM3676 has a mode-control pin that allows the user to select continuous Forced PWM mode over the complete load range or an intelligent PFM-PWM mode that changes modes depending on the load. PWM mode offers superior efficiency under high load conditions (>100mA) and the lowest output noise performance. In Auto mode, PFM-PWM, hysteretic PFM extends the battery life through reduction of the quiescent current to 16µA (typ.) during light loads and system standby.

    The LM3676 is available in a 8-lead non-pullback LLP package in leaded (PB) and lead-free (NO PB) versions. A high switching frequency of 2 MHz (typ) allows use of tiny surface-mount components, an inductor and two ceramic capacitors.


    Applications

  • Mobile phones
  • PDAs
  • MP3 players
  • W-LAN
  • Portable instruments
  • Digital still cameras
  • Portable Hard disk drives



  • Typical Application
    click for larger image


    Block Diagram
    click for larger image



    Typical Performance
    click for larger image


     

    ParametersValues
    Output Current 600 mA
    Input Min Voltage 2.9 Volt
    Input Max Voltage 5.5 Volt
    Output Min 1.1 Volt
    Output Max 3.3 Volt
    Frequency Min 2000 kHz
    Frequency Max 2000 kHz
    Efficiency (peak) 93 %
    Integrated Inductor No
    PowerGood / Error Flag No
    SoftStart Yes
    Sync Pin No
    Inverting No
    Flyback No
    RegType Switching Regulator
    Temperature Min -30 deg C
    Temperature Max 85 deg C
    Adjustable Output Yes
    Adj Switch Frequency No
    PWM Mode Voltage with input feedforward
    Topology Synchronous Buck
    Special Features Pin-selectable PWM/PFM modes, Iq=15uA, 100% duty cycle, internal compensation, ceramic-cap stable, only 3 external components
    Step-Down Yes
    Multiple Output Capability No
    Output Range 1.1V to 3.3V
    Switching Frequency 2000 kHz
    Feedback Voltage Undefined Volt
    On/Off Pin Yes
    Regulator Family Undefined
    AEC Q-100 Automotive Grade Undefined
    Synchronous Rectification Yes

    Datasheets
    TitleSizeDateOther
    Language
    LM3676 2MHz, 600mA Step-Down DC-DC Converter with Mode Control5213
    Kbytes
    11-Mar-07   


    Application Notes
    TitleSizeDateOther
    Language
    AN-1536: Application Note 1536 LM3676 Evaluation Board417
    Kbytes
    14-Oct-08 中文

    Part Number(s)
    (NSID)
    Top ViewAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM3676SD-1.5/NOPB

    LM3676SD-1.5

    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $0.72 each at 1K+ pcsreel
    of
    1000
    LM3676SD-1.8/NOPB

    LM3676SD-1.8

    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide1540
    MOUSERWorldwide970
    $0.72 each at 1K+ pcsreel
    of
    1000
    LM3676SD-3.3/NOPB

    LM3676SD-3.3

    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide1248
    MOUSERWorldwide970
    $0.72 each at 1K+ pcsreel
    of
    1000
    LM3676SD-ADJ/NOPB

    LM3676SD-ADJ

    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide1000
    AVNET-EMWorldwide1000
    DIGI-KEYWorldwide1699
    MOUSERWorldwide970
    TAYLORAmericas1000
    $0.72 each at 1K+ pcsreel
    of
    1000
    LM3676SDX-1.5/NOPB

    LM3676SDX-1.5

    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $0.72 each at 1K+ pcsreel
    of
    4500
    LM3676SDX-1.8/NOPB

    LM3676SDX-1.8

    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $0.72 each at 1K+ pcsreel
    of
    4500
    LM3676SDX-3.3/NOPB

    LM3676SDX-3.3

    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $0.72 each at 1K+ pcsreel
    of
    4500
    LM3676SDX-ADJ/NOPB

    LM3676SDX-ADJ

    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $0.72 each at 1K+ pcsreel
    of
    4500

    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 LM3676.

    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 LM3676 is located at RoHS Status.

    Part Number(s)
    (NSID)
    DescriptionAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM3676SD-ADJEV
    2MHz, 600mA Step-Down DC-DC Converter with Mode ControlFull production


     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    MOUSERWorldwide2
    $53.00 each1

    Description:

    The LM3676 step-down DC-DC converter is optimized for powering low voltage circuits from a single Li-Ion cell battery and input voltage rails from 2.9V to 5.5V. It provides up to 600mA load current, over the entire input voltage range. There are several different fixed voltage output options available as well as an adjustable output voltage version.

    The LM3676 has a mode-control pin that allows the user to select continuous Forced PWM mode over the complete load range or an intelligent PFM-PWM mode that changes modes depending on the load. PWM mode offers superior efficiency under high load conditions (>100mA) and the lowest output noise performance. In Auto mode, PFM-PWM, hysteretic PFM extends the battery life through reduction of the quiescent current to 16 µA (typ.) during light loads and system standby.

    The LM3676 evaluation board is a working demonstration of a step down DC-DC converter. The application note contains information about the evaluation board. For further information on buck converter topology, device electrical characteristics, and component selection please refer to the LM3676 data sheet.

    Features:

    • 16 µA typical quiescent current
    • 600 mA maximum load capability
    • 2MHz PWM fixed switching frequency (typ)
    • Automatic PFM/PWM mode switching or Forced PWM mode
    • Available in fixed output voltages and adjustable version
    • 8-Lead non-pullback LLP package
    • Internal synchronous rectification for high efficiency
    • Internal soft start
    • 0.01 µA typical shutdown current
    • Operates from a single Li-Ion cell battery
    • Only three tiny surface-mount external components required (one inductor, two ceramic capacitors)
    • Current overload and Thermal shutdown protection

    Applications:

    • Mobile Phones
    • PDAs
    • MP3 players
    • W-LAN
    • Portable Instruments
    • Digital still cameras
    • Portable Hard disk drives



    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
    LM3676SD-1.5/NOPB

    LM3676SD-1.5
    20.736
    20.803
    LLP81
    1
    260
    260
    DetailDownloadN/A
    ZXYTT
    S007B
    LM3676SD-1.8/NOPB

    LM3676SD-1.8
    20.736
    20.803
    LLP81
    1
    260
    260
    DetailDownloadN/A
    ZXYTT
    S009B
    LM3676SD-3.3/NOPB

    LM3676SD-3.3
    20.736
    20.803
    LLP81
    1
    260
    260
    DetailDownloadN/A
    ZXYTT
    S010B
    LM3676SD-ADJ/NOPB

    LM3676SD-ADJ
    20.736
    20.803
    LLP81
    1
    260
    260
    DetailDownloadN/A
    ZXYTT
    S008B
    LM3676SDX-1.5/NOPB

    LM3676SDX-1.5
    20.736
    20.803
    LLP81
    1
    260
    260
    DetailDownloadN/A
    ZXYTT
    S007B
    LM3676SDX-1.8/NOPB

    LM3676SDX-1.8
    20.736
    20.803
    LLP81
    1
    260
    260
    DetailDownloadN/A
    ZXYTT
    S009B
    LM3676SDX-3.3/NOPB

    LM3676SDX-3.3
    20.736
    20.803
    LLP81
    1
    260
    260
    DetailDownloadN/A
    ZXYTT
    S010B
    LM3676SDX-ADJ/NOPB

    LM3676SDX-ADJ
    20.736
    20.803
    LLP81
    1
    260
    260
    DetailDownloadN/A
    ZXYTT
    S008B

    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 LM3676.

    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 LM3676 is located at RoHS Status.

    CAD Symbols and Models
    Download LM3676 CAD Symbols
     Models
    N/A


    Reliability Metrics
    Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
    LM3676SD-1.5CMOS70213010015840003449464325
    LM3676SD-1.8CMOS70213010015840003449464325
    LM3676SD-3.3CMOS70213010015840003449464325
    LM3676SD-ADJCMOS70213010015840003449464325
    LM3676SDX-1.5CMOS70213010015840003449464325
    LM3676SDX-1.8CMOS70213010015840003449464325
    LM3676SDX-3.3CMOS70213010015840003449464325
    LM3676SDX-ADJCMOS70213010015840003449464325

    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 LM3676.

    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 LM3676 is located at RoHS Status.

    [Information as of 8-Feb-2012]