National Semiconductor | High-performance Analog

 

 LM2677   
SIMPLE SWITCHER High Efficiency 5A Step-Down Voltage Regulator with Sync 		Click link to Download

Features

  • Efficiency up to 92%
  • Simple and easy to design with (using off-the-shelf external components)
  • 100 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
  • External Sync clock capability (280KHz to 400KHz)
  • 260 KHz fixed frequency internal oscillator
  • −40 to +125°C operating junction temperature range

    • Description

    The LM2677 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 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. The switching clock frequency can be provided by an internal fixed frequency oscillator (260KHz) or from an externally provided clock in the range of 280KHz to 400Khz which allows the use of physically smaller sized components. A family of standard inductors for use with the LM2677 are available from several manufacturers to greatly simplify the design process. The external Sync clock provides direct and precise control of the output ripple frequency for consistent filtering or frequency spectrum positioning.

    The LM2677 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.


    Applications

  • Simple to design, high efficiency (>90%) step-down switching regulators
  • Efficient system pre-regulator for linear voltage regulators
  • Battery chargers
  • Communications and radio equipment regulator with synchronized clock frequency

    • See Layout Guidelines

    WEBENCH® LM2677
        Min   Max   Range  
      VIN – V    8.00 – 40.00V  
      VOUT V    1.21 – 40.00V  
      IOUT A    ≤ 5.00A  
      Ambient Temp °C    ≤ 100°C  
    Footprint BOM Cost Efficiency
    What are WEBENCH® tools?


    Also Recommended
    LM22677▲Fixed 500kHz, And Adjustable Switching Frequency Up To 1MHz



    Typical Application
    click for larger image


    		Block Diagram
    click for larger image



    Typical Performance
    *click for larger image


    Parameters / ValuesLM2677 LM22677
    Output Current5000 mA 5000 mA
    Input Min Voltage15, 8 Volt 4.5 Volt
    Input Max Voltage40 Volt 42 Volt
    Output Min3.3, 1.23, 12, 5 Volt 1.285 Volt
    Output Max3.3, 12, 37, 5 Volt
    Frequency Min260 kHz 200 kHz
    Frequency Max260 kHz 1000 kHz
    Efficiency (peak)84, 92, 82 % 92 %
    On/Off PinYes Yes
    PowerGood / Error FlagNo No
    SoftStartNo No
    Sync PinYes Yes
    FlybackNo No
    RegTypeSwitching Regulator Switching Regulator
    Temperature Min-40 deg C -40 deg C
    Temperature Max125 deg C 125 deg C
    Adjustable OutputYes, No Yes
    Adj Switch FrequencyNo Yes
    PWM ModeVoltage with Vin Feedforward Voltage Mode Control
    TopologyBuck Buck
    Special FeaturesInternal Type 3 compensation, 2% output voltage accuracy, SIMPLE SWITCHER regulator 500 kHz Default Switching Frequency
    Step-DownYes Yes
    Multiple Output CapabilityNo No
    Output PowerUndefined Watt
    Output Voltage3.3, 12, Undefined, 5 Volt
    Output Range12V, 1.23V to 37V, 3.3V, 5V
    Switching Frequency260 kHz 500 kHz
    Regulator FamilySIMPLE SWITCHER SIMPLE SWITCHER
    Synchronous RectificationNo No

    Datasheets
    TitleSizeDateOther
    Language
    LM2677 SIMPLE SWITCHER High Efficiency 5A Step-Down Voltage Regulator with Sync677
    Kbytes    		21-Feb-08   


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

    Part Number(s)
    (NSID)    		Top ViewAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM2677S-12/NOPB

    LM2677S-12

    RoHS Status

    TO-263    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    AVNET-EMWorldwide85
    DIGI-KEYWorldwide435
    FARNELLEurope and Asia17
    MOUSERWorldwide112
    NEWARKAmericas21
    		$3.38 each at 1K+ pcsrail
    of
    45
    LM2677S-3.3/NOPB

    LM2677S-3.3

    RoHS Status

    TO-263    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide117
    AVNET-EMWorldwide35
    DIGI-KEYWorldwide147
    MOUSERWorldwide35
    NEWARKAmericas86
    TAYLORAmericas117
    		$3.38 each at 1K+ pcsrail
    of
    45
    LM2677S-5.0/NOPB

    LM2677S-5.0

    RoHS Status

    TO-263    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    AVNET-EMWorldwide60
    DIGI-KEYWorldwide264
    MOUSERWorldwide130
    RS COMPONENTSWorldwide13
    		$3.38 each at 1K+ pcsrail
    of
    45
    LM2677S-ADJ/NOPB

    LM2677S-ADJ

    RoHS Status

    TO-263    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide314
    AVNET-EMWorldwide394
    DIGI-KEYWorldwide331
    FARNELLEurope and Asia164
    MOUSERWorldwide135
    NEWARKAmericas352
    RS COMPONENTSWorldwide13
    TAYLORAmericas654
    		$3.38 each at 1K+ pcsrail
    of
    45
    LM2677SD-12/NOPB

    LM2677SD-12

    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$3.38 each at 1K+ pcsreel
    of
    250
    LM2677SD-3.3/NOPB


    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$3.38 each at 1K+ pcsreel
    of
    250
    LM2677SD-5.0/NOPB

    LM2677SD-5.0

    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    AVNET-EMWorldwide250
    DIGI-KEYWorldwide314
    MOUSERWorldwide145
    		$3.38 each at 1K+ pcsreel
    of
    250
    LM2677SD-ADJ/NOPB

    LM2677SD-ADJ

    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide113
    FARNELLEurope and Asia527
    MOUSERWorldwide250
    NEWARKAmericas306
    		$3.38 each at 1K+ pcsreel
    of
    250
    LM2677SDX-12

    RoHS Status

    LLP    		Full production
    Lead Time: 16 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$3.38 each at 1K+ pcsreel
    of
    2500
    LM2677SDX-3.3

    RoHS Status

    LLP    		Full production
    Lead Time: 16 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$3.38 each at 1K+ pcsreel
    of
    2500
    LM2677SDX-5.0

    RoHS Status

    LLP    		Full production
    Lead Time: 16 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$3.38 each at 1K+ pcsreel
    of
    2500
    LM2677SDX-ADJ/NOPB

    LM2677SDX-ADJ

    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$3.38 each at 1K+ pcsreel
    of
    2500
    LM2677SX-12/NOPB

    LM2677SX-12

    RoHS Status

    TO-263    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    ARROWWorldwide4000
    AVNET-EMWorldwide1000
    DIGI-KEYWorldwide0
    MOUSERWorldwide470
    TAYLORAmericas4000
    		$3.38 each at 1K+ pcsreel
    of
    500
    LM2677SX-3.3/NOPB

    LM2677SX-3.3

    RoHS Status

    TO-263    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$3.38 each at 1K+ pcsreel
    of
    500
    LM2677SX-5.0/NOPB

    LM2677SX-5.0

    RoHS Status

    TO-263    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$3.38 each at 1K+ pcsreel
    of
    500
    LM2677SX-ADJ/NOPB

    LM2677SX-ADJ

    RoHS Status

    TO-263    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    ARROWWorldwide3490
    DIGI-KEYWorldwide0
    MOUSERWorldwide500
    TAYLORAmericas3490
    		$3.38 each at 1K+ pcsreel
    of
    500
    LM2677T-12/NOPB

    LM2677T-12

    RoHS Status

    TO-220    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    ARROWWorldwide19
    DIGI-KEYWorldwide373
    MOUSERWorldwide135
    TAYLORAmericas19
    		$3.38 each at 1K+ pcsrail
    of
    45
    LM2677T-3.3/NOPB

    LM2677T-3.3

    RoHS Status

    TO-220    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide75
    MOUSERWorldwide135
    		$3.38 each at 1K+ pcsrail
    of
    45
    LM2677T-5.0/NOPB

    LM2677T-5.0

    RoHS Status

    TO-220    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    AVNET-EMWorldwide125
    DIGI-KEYWorldwide174
    MOUSERWorldwide129
    NEWARKAmericas115
    		$3.38 each at 1K+ pcsrail
    of
    45
    LM2677T-ADJ/NOPB

    LM2677T-ADJ

    RoHS Status

    TO-220    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide135
    AVNET-EMWorldwide135
    DIGI-KEYWorldwide25
    FARNELLEurope and Asia227
    NEWARKAmericas75
    RS COMPONENTSWorldwide15
    TAYLORAmericas135
    		$3.38 each at 1K+ pcsrail
    of
    45

    Obsolete Versions
    Obsolete PartAlternate Part or SupplierSourceLast Time Buy Date
    LM2677LD-12
    		NONE
    		NONE
    		30 Jan 2004
    LM2677LD-3.3
    		NONE
    		NONE
    		30 Jan 2004
    LM2677LD-5.0
    		NONE
    		NONE
    		30 Jan 2004
    LM2677LD-ADJ
    		NONE
    		NONE
    		30 Jan 2004
    LM2677LDX-12
    		NONE
    		NONE
    		30 Jan 2004
    LM2677LDX-3.3
    		NONE
    		NONE
    		30 Jan 2004
    LM2677LDX-5.0
    		NONE
    		NONE
    		30 Jan 2004
    LM2677LDX-ADJ
    		NONE
    		NONE
    		30 Jan 2004

    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 LM2677.

    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 LM2677 is located at RoHS Status.

    Part Number(s)
    (NSID)    		Weight
    (milligrams)    		TypePinsMSL RatingPeak ReflowRoHS
    Status    		CAD SymbolsModelsPackage
    Marking
    Format
    LM2677S-12/NOPB

    LM2677S-12
    		1608.332
    1609.822
    		TO-26373
    3    		245
    235    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2677S
    -12
    LM2677S-3.3/NOPB

    LM2677S-3.3
    		1608.332
    1609.822
    		TO-26373
    3    		245
    235    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2677S
    -3.3
    LM2677S-5.0/NOPB

    LM2677S-5.0
    		1608.332
    1609.822
    		TO-26373
    3    		245
    235    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2677S
    -5.0
    LM2677S-ADJ/NOPB

    LM2677S-ADJ
    		1608.332
    1609.822
    		TO-26373
    3    		245
    235    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2677S
    -ADJ
    LM2677SD-12/NOPB

    LM2677SD-12
    		94.439
    94.76
    		LLP141
    1    		260
    260    		DetailDownloadN/A
    		NS
    UZXYTT
    S0002XB
    LM2677SD-3.3/NOPB

    		94.439
    		LLP141260DetailDownloadN/A
    		NS
    UZXYTT
    S0002YB
    LM2677SD-5.0/NOPB

    LM2677SD-5.0
    		94.439
    94.76
    		LLP141
    1    		260
    260    		DetailDownloadN/A
    		NS
    UZXYTT
    S0002ZB
    LM2677SD-ADJ/NOPB

    LM2677SD-ADJ
    		94.439
    94.76
    		LLP141
    1    		260
    260    		DetailDownloadN/A
    		NS
    UZXYTT
    S0003AB
    LM2677SDX-12
    		94.76
    		LLP141260DetailDownloadN/A
    		NS
    UZXYTT
    S0002XB
    LM2677SDX-3.3
    		94.76
    		LLP141260DetailDownloadN/A
    		NS
    UZXYTT
    S0002YB
    LM2677SDX-5.0
    		94.76
    		LLP141260DetailDownloadN/A
    		NS
    UZXYTT
    S0002ZB
    LM2677SDX-ADJ/NOPB

    LM2677SDX-ADJ
    		94.439
    94.76
    		LLP141
    1    		260
    260    		DetailDownloadN/A
    		NS
    UZXYTT
    S0003AB
    LM2677SX-12/NOPB

    LM2677SX-12
    		1608.332
    1609.822
    		TO-26373
    3    		245
    235    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2677S
    -12
    LM2677SX-3.3/NOPB

    LM2677SX-3.3
    		1608.332
    1609.822
    		TO-26373
    3    		245
    235    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2677S
    -3.3
    LM2677SX-5.0/NOPB

    LM2677SX-5.0
    		1608.332
    1609.822
    		TO-26373
    3    		245
    235    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2677S
    -5.0
    LM2677SX-ADJ/NOPB

    LM2677SX-ADJ
    		1608.332
    1609.822
    		TO-26373
    3    		245
    235    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2677S
    -ADJ
    LM2677T-12/NOPB

    LM2677T-12
    		1846.782
    1858.793
    		TO-22071
    1    		NA
    NA    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2677T
    -12
    LM2677T-3.3/NOPB

    LM2677T-3.3
    		1846.782
    1858.793
    		TO-22071
    1    		NA
    NA    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2677T
    -3.3
    LM2677T-5.0/NOPB

    LM2677T-5.0
    		1846.782
    1858.793
    		TO-22071
    1    		NA
    NA    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2677T
    -5.0
    LM2677T-ADJ/NOPB

    LM2677T-ADJ
    		1846.782
    1858.793
    		TO-22071
    1    		NA
    NA    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2677T
    -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 LM2677.

    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 LM2677 is located at RoHS Status.

    CAD Symbols and Models
    Download LM2677 CAD Symbols
    		 Models
    N/A


    Reliability Metrics
    Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
    LM2677S-12LMDMOS0182950026500002751944735
    LM2677S-3.3LMDMOS0182950026500002751944735
    LM2677S-5.0LMDMOS0182950026500002751944735
    LM2677S-ADJLMDMOS0182950026500002751944735
    LM2677SD-12LMDMOS0182950026500002751944735
    LM2677SD-3.3LMDMOS0182950026500002751944735
    LM2677SD-5.0LMDMOS0182950026500002751944735
    LM2677SD-ADJLMDMOS0182950026500002751944735
    LM2677SDX-12LMDMOS0182950026500002751944735
    LM2677SDX-3.3LMDMOS0182950026500002751944735
    LM2677SDX-5.0LMDMOS0182950026500002751944735
    LM2677SDX-ADJLMDMOS0182950026500002751944735
    LM2677SX-12LMDMOS0182950026500002751944735
    LM2677SX-3.3LMDMOS0182950026500002751944735
    LM2677SX-5.0LMDMOS0182950026500002751944735
    LM2677SX-ADJLMDMOS0182950026500002751944735
    LM2677T-12LMDMOS0182950026500002751944735
    LM2677T-3.3LMDMOS0182950026500002751944735
    LM2677T-5.0LMDMOS0182950026500002751944735
    LM2677T-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 LM2677.

    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 LM2677 is located at RoHS Status.

    Obsolete Versions
    Obsolete PartAlternate Part or SupplierSourceLast Time Buy Date
    LM2677LD-12
    		NONE
    		NONE
    		30 Jan 2004
    LM2677LD-3.3
    		NONE
    		NONE
    		30 Jan 2004
    LM2677LD-5.0
    		NONE
    		NONE
    		30 Jan 2004
    LM2677LD-ADJ
    		NONE
    		NONE
    		30 Jan 2004
    LM2677LDX-12
    		NONE
    		NONE
    		30 Jan 2004
    LM2677LDX-3.3
    		NONE
    		NONE
    		30 Jan 2004
    LM2677LDX-5.0
    		NONE
    		NONE
    		30 Jan 2004
    LM2677LDX-ADJ
    		NONE
    		NONE
    		30 Jan 2004

    [Information as of 8-Feb-2012]
    Copyright © 2011 National Semiconductor Corporation