National Semiconductor | High-performance Analog

 

 LM2676   

SIMPLE SWITCHER High Efficiency 3A Step-Down Voltage Regulator
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Features

  • Efficiency up to 94%
  • Simple and easy to design with (using off-the-shelf external components)
  • 150 mΩ DMOS output switch
  • 3.3V, 5V and 12V fixed output and adjustable (1.2V to 37V ) versions
  • 50μA standby current when switched OFF
  • ±2%maximum output tolerance over full line and load conditions
  • Wide input voltage range: 8V to 40V
  • 260 KHz fixed frequency internal oscillator
  • −40 to +125°C operating junction temperature range
  • Description

    The LM2676 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 3A loads with excellent line and load regulation characteristics. High efficiency (>90%) is obtained through the use of a low ON-resistance DMOS power switch. The series consists of fixed output voltages of 3.3V, 5V and 12V and an adjustable output version.

    The SIMPLE SWITCHER concept provides for a complete design using a minimum number of external components. A high fixed frequency oscillator (260KHz) allows the use of physically smaller sized components. A family of standard inductors for use with the LM2676 are available from several manufacturers to greatly simplify the design process.

    The LM2676 series also has built in thermal shutdown, current limiting and an ON/OFF control input that can power down the regulator to a low 50μA quiescent current standby condition. The output voltage is guaranteed to a ±2% tolerance. The clock frequency is controlled to within a ±11% tolerance.


    Applications

  • Simple to design, high efficiency (>90%) step-down switching regulators
  • Efficient system pre-regulator for linear voltage regulators
  • Battery chargers
  • See Layout Guidelines

    WEBENCH® LM2676
        Min   Max   Range  
      VIN V    8.00 – 40.00V  
      VOUT V    1.21 – 40.00V  
      IOUT A    ≤ 3.00A  
      Ambient Temp °C    ≤ 100°C  
    Footprint BOM Cost Efficiency
    What are WEBENCH® tools?


    Also Recommended
    LM22676Wider Input Voltage Range (6 To 42V), Fixed 500kHz
    LM25576Fast-Transient Response And Higher Switching Frequency (Up To 1MHz)
    LM557675V Vin 3A Regulator



    Typical Application
    click for larger image


    Block Diagram
    click for larger image



    Typical Performance
    *click for larger image


    Parameters / ValuesLM2676 LM22676 LM25576 LM5576
    Output Current3000 mA 3000 mA 3000 mA 3000 mA
    Input Min Voltage15, 8 Volt 4.5 Volt 6 Volt 6 Volt
    Input Max Voltage40 Volt 42 Volt 42 Volt 75 Volt
    Output Min3.3, 1.23, 12, 5 Volt 1.285 Volt 1.23 Volt 1.23 Volt
    Output Max3.3, 12, 37, 5 Volt 40 Volt 70 Volt
    Frequency Min260 kHz 50 kHz 50 kHz
    Frequency Max260 kHz 1000 kHz 500 kHz
    Efficiency (peak)94, 88, 86 % 92 % 91 % 88 %
    On/Off PinYes Yes Yes Yes
    PowerGood / Error FlagNo No No No
    SoftStartNo No Yes Yes
    Sync PinNo No Yes Yes
    FlybackNo No No No
    RegTypeSwitching Regulator Switching Regulator Switching Regulator Switching Regulator
    Temperature Min-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
    Adjustable OutputYes, No Yes Yes Yes
    Adj Switch FrequencyNo No Yes Yes
    PWM ModeVoltage with Vin Feedforward Voltage Mode Control Current Current
    TopologyBuck Buck Buck Buck
    Special FeaturesInternal Type 3 compensation, 2% output voltage accuracy, SIMPLE SWITCHER regulator 500 kHz Switching Frequency 1.5% feedback voltage accuracy, emulated current mode 1.5% feedback voltage accuracy, emulated current mode
    Step-DownYes Yes Yes Yes
    Multiple Output CapabilityNo No No No
    Output PowerUndefined Watt Undefined Watt Undefined Watt
    Output Voltage3.3, 12, Undefined, 5 Volt Undefined Volt Undefined Volt
    Output Range12V, 1.23V to 37V, 3.3V, 5V 1.23V to 37V 1.23V to 70V
    Switching Frequency260 kHz 500 kHz 1000 kHz 500 kHz
    Regulator FamilySIMPLE SWITCHER SIMPLE SWITCHER SIMPLE SWITCHER SIMPLE SWITCHER
    Synchronous RectificationNo No No No

    Datasheets
    TitleSizeDateOther
    Language
    LM2676 SIMPLE SWITCHER High Efficiency 3A Step-Down Voltage Regulator671
    Kbytes
    29-Feb-08日本語  


    Application Notes
    TitleSizeDateOther
    Language
    AN-1135: Application Note 1135 LM267X 3A, 5A Evaluation Boards2433
    Kbytes
    4-Mar-11 


    Other Technical Documents
    TitleTypeDate
    How to supply, load, and test power-management circuits Part 1External Article 2008-04-09

    Part Number(s)
    (NSID)
    Top ViewAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM2676S-12/NOPB

    LM2676S-12

    RoHS Status


    TO-263
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide213
    AVNET-EMWorldwide1250
    BRITESTONESouth Korea4
    DIGI-KEYWorldwide1272
    FARNELLEurope and Asia760
    MOUSERWorldwide74
    NEWARKAmericas562
    RS COMPONENTSWorldwide50
    TAYLORAmericas440
    $1.92 each at 1K+ pcsrail
    of
    45
    LM2676S-3.3/NOPB

    LM2676S-3.3

    RoHS Status


    TO-263
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide551
    AVNET-EMWorldwide2549
    BRITESTONESouth Korea133
    DIGI-KEYWorldwide667
    MOUSERWorldwide169
    NEWARKAmericas5
    RS COMPONENTSWorldwide119
    TAYLORAmericas2775
    $1.92 each at 1K+ pcsrail
    of
    45
    LM2676S-5.0/NOPB

    LM2676S-5.0

    RoHS Status


    TO-263
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide715
    AVNET-EMWorldwide3640
    BRITESTONESouth Korea104
    CEACAsia Pacific630
    DIGI-KEYWorldwide1882
    MOUSERWorldwide230
    NEWARKAmericas1313
    RS COMPONENTSWorldwide222
    TAYLORAmericas6849
    $1.92 each at 1K+ pcsrail
    of
    45
    LM2676S-ADJ/NOPB

    LM2676S-ADJ

    RoHS Status


    TO-263
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide1195
    AVNET-EMWorldwide72
    BRITESTONESouth Korea8
    DIGI-KEYWorldwide11298
    FARNELLEurope and Asia4636
    MOUSERWorldwide395
    NEWARKAmericas6923
    RS COMPONENTSWorldwide100
    RSL MICROAsia Pacific6300
    TAYLORAmericas4377
    TECHMOSAAsia Pacific765
    $1.92 each at 1K+ pcsrail
    of
    45
    LM2676SD-12/NOPB

    LM2676SD-12

    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide250
    AVNET-EMWorldwide250
    DIGI-KEYWorldwide759
    MOUSERWorldwide150
    TAYLORAmericas250
    $1.92 each at 1K+ pcsreel
    of
    250
    LM2676SD-3.3/NOPB

    LM2676SD-3.3

    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide392
    AVNET-EMWorldwide250
    DIGI-KEYWorldwide414
    MOUSERWorldwide50
    TAYLORAmericas392
    $1.92 each at 1K+ pcsreel
    of
    250
    LM2676SD-5.0/NOPB

    LM2676SD-5.0

    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide250
    AVNET-EMWorldwide250
    DIGI-KEYWorldwide668
    MOUSERWorldwide150
    NEWARKAmericas254
    TAYLORAmericas1250
    $1.92 each at 1K+ pcsreel
    of
    250
    LM2676SD-ADJ/NOPB

    LM2676SD-ADJ

    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide485
    AVNET-EMWorldwide250
    DIGI-KEYWorldwide936
    MOUSERWorldwide150
    NEWARKAmericas178
    RS COMPONENTSWorldwide250
    TAYLORAmericas719
    $1.92 each at 1K+ pcsreel
    of
    250
    LM2676SDX-12/NOPB

    LM2676SDX-12

    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $1.92 each at 1K+ pcsreel
    of
    2500
    LM2676SDX-3.3/NOPB


    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $1.92 each at 1K+ pcsreel
    of
    2500
    LM2676SDX-5.0/NOPB

    LM2676SDX-5.0

    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $1.92 each at 1K+ pcsreel
    of
    2500
    LM2676SDX-ADJ/NOPB

    LM2676SDX-ADJ

    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    ARROWWorldwide5000
    DIGI-KEYWorldwide0
    TAYLORAmericas5000
    $1.92 each at 1K+ pcsreel
    of
    2500
    LM2676SX-12/NOPB

    LM2676SX-12

    RoHS Status


    TO-263
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    ARROWWorldwide2450
    BRITESTONESouth Korea2000
    DIGI-KEYWorldwide0
    MOUSERWorldwide400
    RSL MICROAsia Pacific1500
    TAYLORAmericas2450
    $1.92 each at 1K+ pcsreel
    of
    500
    LM2676SX-3.3/NOPB

    LM2676SX-3.3

    RoHS Status


    TO-263
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    ARROWWorldwide500
    AVNET-EMWorldwide1940
    DIGI-KEYWorldwide0
    MOUSERWorldwide500
    NEWARKAmericas203
    TAYLORAmericas1897
    $1.92 each at 1K+ pcsreel
    of
    500
    LM2676SX-5.0/NOPB

    LM2676SX-5.0

    RoHS Status


    TO-263
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    ARROWWorldwide500
    AVNET-EMWorldwide4000
    DIGI-KEYWorldwide0
    MOUSERWorldwide423
    NEWARKAmericas72
    RSL MICROAsia Pacific7500
    TAYLORAmericas14326
    $1.92 each at 1K+ pcsreel
    of
    500
    LM2676SX-ADJ/NOPB

    LM2676SX-ADJ

    RoHS Status


    TO-263
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    ARROWWorldwide1000
    AVNET-EMWorldwide4000
    BRITESTONESouth Korea2
    DIGI-KEYWorldwide0
    MOUSERWorldwide490
    TAYLORAmericas2221
    TECHMOSAAsia Pacific500
    $1.92 each at 1K+ pcsreel
    of
    500
    LM2676T-12/NOPB

    LM2676T-12

    RoHS Status


    TO-220
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    AVNET-EMWorldwide375
    DIGI-KEYWorldwide134
    FARNELLEurope and Asia180
    MOUSERWorldwide46
    NEWARKAmericas39
    RS COMPONENTSWorldwide28
    $1.92 each at 1K+ pcsrail
    of
    45
    LM2676T-3.3/NOPB

    LM2676T-3.3

    RoHS Status


    TO-220
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide45
    AVNET-EMWorldwide170
    DIGI-KEYWorldwide348
    MOUSERWorldwide176
    RS COMPONENTSWorldwide16
    TAYLORAmericas45
    $1.92 each at 1K+ pcsrail
    of
    45
    LM2676T-5.0/NOPB

    LM2676T-5.0

    RoHS Status


    TO-220
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide275
    AVNET-EMWorldwide194
    BRITESTONESouth Korea8
    DIGI-KEYWorldwide1251
    MOUSERWorldwide178
    NEWARKAmericas11
    RS COMPONENTSWorldwide49
    TAYLORAmericas275
    $1.92 each at 1K+ pcsrail
    of
    45
    LM2676T-ADJ/NOPB

    LM2676T-ADJ

    RoHS Status


    TO-220
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide3465
    AVNET-EMWorldwide85
    DIGI-KEYWorldwide3303
    FARNELLEurope and Asia1790
    MOUSERWorldwide165
    NEWARKAmericas29
    RS COMPONENTSWorldwide60
    RSL MICROAsia Pacific4860
    TAYLORAmericas3465
    $1.92 each at 1K+ pcsrail
    of
    45

    Obsolete Versions
    Obsolete PartAlternate Part or SupplierSourceLast Time Buy Date
    LM2676D-12
    NONE
    NONE
    30 Jan 2004
    LM2676LD-3.3
    NONE
    NONE
    30 Jan 2004
    LM2676LD-5.0
    NONE
    NONE
    30 Jan 2004
    LM2676LD-ADJ
    NONE
    NONE
    30 Jan 2004
    LM2676LDX-12
    NONE
    NONE
    30 Jan 2004
    LM2676LDX-3.3
    NONE
    NONE
    30 Jan 2004
    LM2676LDX-5.0
    NONE
    NONE
    30 Jan 2004
    LM2676LDX-ADJ
    NONE
    NONE
    30 Jan 2004
    LM2676S-5.0EP
    NONE
    NATIONAL SEMICONDUCTOR
    16 Nov 2008

    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 LM2676.

    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 LM2676 is located at RoHS Status.

    Part Number(s)
    (NSID)
    Weight
    (milligrams)
    TypePinsMSL RatingPeak ReflowRoHS
    Status
    CAD SymbolsModelsPackage
    Marking
    Format
    LM2676S-12/NOPB

    LM2676S-12
    1608.332
    1609.822
    TO-26373
    3
    245
    235
    DetailDownloadN/A
    NSUZXYTTE#
    LM2676
    S-12
    LM2676S-3.3/NOPB

    LM2676S-3.3
    1608.332
    1609.822
    TO-26373
    3
    245
    235
    DetailDownloadN/A
    NSUZXYTTE#
    LM2676
    S-3.3
    LM2676S-5.0/NOPB

    LM2676S-5.0
    1608.332
    1609.822
    TO-26373
    3
    245
    235
    DetailDownloadN/A
    NSUZXYTTE#
    LM2676
    S-5.0
    LM2676S-ADJ/NOPB

    LM2676S-ADJ
    1608.332
    1609.822
    TO-26373
    3
    245
    235
    DetailDownloadN/A
    NSUZXYTTE#
    LM2676
    S-ADJ
    LM2676SD-12/NOPB

    LM2676SD-12
    94.439
    94.76
    LLP141
    1
    260
    260
    DetailDownloadN/A
    NS
    UZXYTT
    S0003LB
    LM2676SD-3.3/NOPB

    LM2676SD-3.3
    94.439
    94.76
    LLP141
    1
    260
    260
    DetailDownloadN/A
    NS
    UZXYTT
    S0003NB
    LM2676SD-5.0/NOPB

    LM2676SD-5.0
    94.439
    94.76
    LLP141
    1
    260
    260
    DetailDownloadN/A
    NS
    UZXYTT
    S0003PB
    LM2676SD-ADJ/NOPB

    LM2676SD-ADJ
    94.439
    94.76
    LLP141
    1
    260
    260
    DetailDownloadN/A
    NS
    UZXYTT
    S0003RB
    LM2676SDX-12/NOPB

    LM2676SDX-12
    94.439
    94.76
    LLP141
    1
    260
    260
    DetailDownloadN/A
    NS
    UZXYTT
    S0003LB
    LM2676SDX-3.3/NOPB

    94.439
    LLP141260DetailDownloadN/A
    NS
    UZXYTT
    S0003NB
    LM2676SDX-5.0/NOPB

    LM2676SDX-5.0
    94.439
    94.76
    LLP141
    1
    260
    260
    DetailDownloadN/A
    NS
    UZXYTT
    S0003PB
    LM2676SDX-ADJ/NOPB

    LM2676SDX-ADJ
    94.439
    94.76
    LLP141
    1
    260
    260
    DetailDownloadN/A
    NS
    UZXYTT
    S0003RB
    LM2676SX-12/NOPB

    LM2676SX-12
    1608.332
    1609.822
    TO-26373
    3
    245
    235
    DetailDownloadN/A
    NSUZXYTTE#
    LM2676
    S-12
    LM2676SX-3.3/NOPB

    LM2676SX-3.3
    1608.332
    1609.822
    TO-26373
    3
    245
    235
    DetailDownloadN/A
    NSUZXYTTE#
    LM2676
    S-3.3
    LM2676SX-5.0/NOPB

    LM2676SX-5.0
    1608.332
    1609.822
    TO-26373
    3
    245
    235
    DetailDownloadN/A
    NSUZXYTTE#
    LM2676
    S-5.0
    LM2676SX-ADJ/NOPB

    LM2676SX-ADJ
    1608.332
    1609.822
    TO-26373
    3
    245
    235
    DetailDownloadN/A
    NSUZXYTTE#
    LM2676
    S-ADJ
    LM2676T-12/NOPB

    LM2676T-12
    1846.782
    1858.793
    TO-22071
    1
    NA
    NA
    DetailDownloadN/A
    NSUZXYTTE#
    LM2676
    T-12
    LM2676T-3.3/NOPB

    LM2676T-3.3
    1846.782
    1858.793
    TO-22071
    1
    NA
    NA
    DetailDownloadN/A
    NSUZXYTTE#
    LM2676
    T-3.3
    LM2676T-5.0/NOPB

    LM2676T-5.0
    1846.782
    1858.793
    TO-22071
    1
    NA
    NA
    DetailDownloadN/A
    NSUZXYTTE#
    LM2676
    T-5.0
    LM2676T-ADJ/NOPB

    LM2676T-ADJ
    1846.782
    1858.793
    TO-22071
    1
    NA
    NA
    DetailDownloadN/A
    NSUZXYTTE#
    LM2676
    T-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 LM2676.

    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 LM2676 is located at RoHS Status.

    Reliability Metrics
    Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
    LM2676S-12LMDMOS0182950026500002751944735
    LM2676S-3.3LMDMOS0182950026500002751944735
    LM2676S-5.0LMDMOS0182950026500002751944735
    LM2676S-ADJLMDMOS0182950026500002751944735
    LM2676SD-12LMDMOS0182950026500002751944735
    LM2676SD-3.3LMDMOS0182950026500002751944735
    LM2676SD-5.0LMDMOS0182950026500002751944735
    LM2676SD-ADJLMDMOS0182950026500002751944735
    LM2676SDX-12LMDMOS0182950026500002751944735
    LM2676SDX-3.3LMDMOS0182950026500002751944735
    LM2676SDX-5.0LMDMOS0182950026500002751944735
    LM2676SDX-ADJLMDMOS0182950026500002751944735
    LM2676SX-12LMDMOS0182950026500002751944735
    LM2676SX-3.3LMDMOS0182950026500002751944735
    LM2676SX-5.0LMDMOS0182950026500002751944735
    LM2676SX-ADJLMDMOS0182950026500002751944735
    LM2676T-12LMDMOS0182950026500002751944735
    LM2676T-3.3LMDMOS0182950026500002751944735
    LM2676T-5.0LMDMOS0182950026500002751944735
    LM2676T-ADJLMDMOS0182950026500002751944735

    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 LM2676.

    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 LM2676 is located at RoHS Status.

    Obsolete Versions
    Obsolete PartAlternate Part or SupplierSourceLast Time Buy Date
    LM2676D-12
    NONE
    NONE
    30 Jan 2004
    LM2676LD-3.3
    NONE
    NONE
    30 Jan 2004
    LM2676LD-5.0
    NONE
    NONE
    30 Jan 2004
    LM2676LD-ADJ
    NONE
    NONE
    30 Jan 2004
    LM2676LDX-12
    NONE
    NONE
    30 Jan 2004
    LM2676LDX-3.3
    NONE
    NONE
    30 Jan 2004
    LM2676LDX-5.0
    NONE
    NONE
    30 Jan 2004
    LM2676LDX-ADJ
    NONE
    NONE
    30 Jan 2004
    LM2676S-5.0EP
    NONE
    NATIONAL SEMICONDUCTOR
    16 Nov 2008

    [Information as of 8-Feb-2012]