National Semiconductor | High-performance Analog

 

 LM2670   
SIMPLE SWITCHER High Efficiency 3A Step-Down Voltage Regulator with Sync 		Click link to Download

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
  • External Sync clock capability (280KHz to 400KHz)
  • 260 KHz fixed frequency internal oscillator
  • −40 to +125°C operating junction temperature range

    • Description

    The LM2670 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. 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 LM2670 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 LM2670 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® LM2670
        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
    LM22670▲Wider Input Voltage Range (4.5V To 42V), Adjustable Switching Frequency Up To 1MHz
    LM25576▲For Ultra-Fast Transient Response
    LM5576▲Wider Input Voltage Range (6 To 75V) And Higher Switching Frequency (Up To 500kHz)



    Typical Application
    click for larger image


    		Block Diagram
    click for larger image



    Typical Performance
    *click for larger image


    Parameters / ValuesLM2670 LM22670 LM25576 LM5576
    Output Current3000 mA 3000 mA 3000 mA 3000 mA
    Input Min Voltage8 Volt 4.5 Volt 6 Volt 6 Volt
    Input Max Voltage40 Volt 42 Volt 42 Volt 75 Volt
    Output Min1.23 Volt 1.285 Volt 1.23 Volt 1.23 Volt
    Output Max37 Volt 40 Volt 70 Volt
    Frequency Min260 kHz 200 kHz 50 kHz 50 kHz
    Frequency Max260 kHz 1000 kHz 1000 kHz 500 kHz
    Efficiency (peak)94 % 92 % 91 % 88 %
    On/Off PinYes Yes Yes Yes
    PowerGood / Error FlagNo No No No
    SoftStartNo No Yes Yes
    Sync PinYes Yes 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 OutputNo Yes Yes Yes
    Adj Switch FrequencyNo Yes 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 Default 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 Voltage12 Volt Undefined Volt Undefined Volt
    Output Range12V 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
    LM2670 SIMPLE SWITCHER High Efficiency 3A Step-Down Voltage Regulator with Sync669
    Kbytes    		1-May-08日本語  


    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
    LM2670S-12/NOPB

    LM2670S-12

    RoHS Status

    TO-263    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide116
    AVNET-EMWorldwide74
    DIGI-KEYWorldwide315
    MOUSERWorldwide180
    NEWARKAmericas276
    TAYLORAmericas116
    		$1.98 each at 1K+ pcsrail
    of
    45
    LM2670S-3.3/NOPB

    LM2670S-3.3

    RoHS Status

    TO-263    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    AVNET-EMWorldwide739
    DIGI-KEYWorldwide258
    MOUSERWorldwide120
    NEWARKAmericas19
    		$1.98 each at 1K+ pcsrail
    of
    45
    LM2670S-5.0/NOPB

    LM2670S-5.0

    RoHS Status

    TO-263    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide123
    AVNET-EMWorldwide113
    DIGI-KEYWorldwide444
    MOUSERWorldwide143
    NEWARKAmericas129
    RS COMPONENTSWorldwide40
    TAYLORAmericas1158
    		$1.98 each at 1K+ pcsrail
    of
    45
    LM2670S-ADJ/NOPB

    LM2670S-ADJ

    RoHS Status

    TO-263    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide33
    AVNET-EMWorldwide229
    DIGI-KEYWorldwide313
    MOUSERWorldwide88
    NEWARKAmericas266
    RS COMPONENTSWorldwide67
    TAYLORAmericas174
    		$1.98 each at 1K+ pcsrail
    of
    45
    LM2670SD-12/NOPB

    LM2670SD-12

    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide563
    MOUSERWorldwide250
    		$1.98 each at 1K+ pcsreel
    of
    250
    LM2670SD-3.3/NOPB

    LM2670SD-3.3

    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide803
    MOUSERWorldwide250
    		$1.98 each at 1K+ pcsreel
    of
    250
    LM2670SD-5.0/NOPB

    LM2670SD-5.0

    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    ARROWWorldwide250
    DIGI-KEYWorldwide775
    MOUSERWorldwide248
    RSL MICROAsia Pacific1500
    TAYLORAmericas250
    		$1.98 each at 1K+ pcsreel
    of
    250
    LM2670SD-ADJ/NOPB

    LM2670SD-ADJ

    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide250
    DIGI-KEYWorldwide1437
    FARNELLEurope and Asia797
    MOUSERWorldwide225
    NEWARKAmericas182
    TAYLORAmericas250
    		$1.98 each at 1K+ pcsreel
    of
    250
    LM2670SDX-12

    RoHS Status

    LLP    		Full production
    Lead Time: 16 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.98 each at 1K+ pcsreel
    of
    2500
    LM2670SDX-3.3/NOPB


    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.98 each at 1K+ pcsreel
    of
    2500
    LM2670SDX-5.0/NOPB


    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.98 each at 1K+ pcsreel
    of
    2500
    LM2670SDX-ADJ/NOPB

    LM2670SDX-ADJ

    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.98 each at 1K+ pcsreel
    of
    2500
    LM2670SX-12/NOPB

    LM2670SX-12

    RoHS Status

    TO-263    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.98 each at 1K+ pcsreel
    of
    500
    LM2670SX-3.3/NOPB

    LM2670SX-3.3

    RoHS Status

    TO-263    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.98 each at 1K+ pcsreel
    of
    500
    LM2670SX-5.0/NOPB

    LM2670SX-5.0

    RoHS Status

    TO-263    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    MOUSERWorldwide500
    		$1.98 each at 1K+ pcsreel
    of
    500
    LM2670SX-ADJ/NOPB

    LM2670SX-ADJ

    RoHS Status

    TO-263    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    ARROWWorldwide4000
    AVNET-EMWorldwide685
    DIGI-KEYWorldwide0
    MOUSERWorldwide500
    TAYLORAmericas4000
    		$1.98 each at 1K+ pcsreel
    of
    500
    LM2670T-12/NOPB


    RoHS Status

    TO-220    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    MOUSERWorldwide180
    		$1.98 each at 1K+ pcsrail
    of
    45
    LM2670T-3.3/NOPB

    LM2670T-3.3

    RoHS Status

    TO-220    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide328
    MOUSERWorldwide180
    		$1.98 each at 1K+ pcsrail
    of
    45
    LM2670T-5.0/NOPB

    LM2670T-5.0

    RoHS Status

    TO-220    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide184
    DIGI-KEYWorldwide120
    MOUSERWorldwide180
    TAYLORAmericas184
    		$1.98 each at 1K+ pcsrail
    of
    45
    LM2670T-ADJ/NOPB

    LM2670T-ADJ

    RoHS Status

    TO-220    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide35
    AVNET-EMWorldwide137
    DIGI-KEYWorldwide471
    FARNELLEurope and Asia85
    MOUSERWorldwide180
    NEWARKAmericas58
    RS COMPONENTSWorldwide30
    TAYLORAmericas35
    		$1.98 each at 1K+ pcsrail
    of
    45

    Obsolete Versions
    Obsolete PartAlternate Part or SupplierSourceLast Time Buy Date
    LM2670LD-12
    		NONE
    		NONE
    		30 Jan 2004
    LM2670LD-3.3
    		NONE
    		NONE
    		30 Jan 2004
    LM2670LD-5.0
    		NONE
    		NONE
    		30 Jan 2004
    LM2670LD-ADJ
    		NONE
    		NONE
    		30 Jan 2004
    LM2670LDX-12
    		NONE
    		NONE
    		30 Jan 2004
    LM2670LDX-3.3
    		NONE
    		NONE
    		30 Jan 2004
    LM2670LDX-5.0
    		NONE
    		NONE
    		30 Jan 2004
    LM2670LDX-ADJ
    		NONE
    		NONE
    		30 Jan 2004
    LM2670SX-ADJEP
    		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 LM2670.

    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 LM2670 is located at RoHS Status.

    Part Number(s)
    (NSID)    		Weight
    (milligrams)    		TypePinsMSL RatingPeak ReflowRoHS
    Status    		CAD SymbolsModelsPackage
    Marking
    Format
    LM2670S-12/NOPB

    LM2670S-12
    		1608.332
    1609.822
    		TO-26373
    3    		245
    235    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2670
    S-12
    LM2670S-3.3/NOPB

    LM2670S-3.3
    		1608.332
    1609.822
    		TO-26373
    3    		245
    235    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2670
    S-3.3
    LM2670S-5.0/NOPB

    LM2670S-5.0
    		1608.332
    1609.822
    		TO-26373
    3    		245
    235    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2670
    S-5.0
    LM2670S-ADJ/NOPB

    LM2670S-ADJ
    		1608.332
    1609.822
    		TO-26373
    3    		245
    235    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2670
    S-ADJ
    LM2670SD-12/NOPB

    LM2670SD-12
    		94.439
    94.76
    		LLP141
    1    		260
    260    		DetailDownloadN/A
    		NS
    UZXYTT
    S0002LB
    LM2670SD-3.3/NOPB

    LM2670SD-3.3
    		94.439
    94.76
    		LLP141
    1    		260
    260    		DetailDownloadN/A
    		NS
    UZXYTT
    S0002NB
    LM2670SD-5.0/NOPB

    LM2670SD-5.0
    		94.439
    94.76
    		LLP141
    1    		260
    260    		DetailDownloadN/A
    		NS
    UZXYTT
    S0002PB
    LM2670SD-ADJ/NOPB

    LM2670SD-ADJ
    		94.439
    94.76
    		LLP141
    1    		260
    260    		DetailDownloadN/A
    		NS
    UZXYTT
    S0002RB
    LM2670SDX-12
    		94.76
    		LLP141260DetailDownloadN/A
    		NS
    UZXYTT
    S0002LB
    LM2670SDX-3.3/NOPB

    		94.439
    		LLP141260DetailDownloadN/A
    		NS
    UZXYTT
    S0002NB
    LM2670SDX-5.0/NOPB

    		94.439
    		LLP141260DetailDownloadN/A
    		NS
    UZXYTT
    S0002PB
    LM2670SDX-ADJ/NOPB

    LM2670SDX-ADJ
    		94.439
    94.76
    		LLP141
    1    		260
    260    		DetailDownloadN/A
    		NS
    UZXYTT
    S0002RB
    LM2670SX-12/NOPB

    LM2670SX-12
    		1608.332
    1609.822
    		TO-26373
    3    		245
    235    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2670
    S-12
    LM2670SX-3.3/NOPB

    LM2670SX-3.3
    		1608.332
    1609.822
    		TO-26373
    3    		245
    235    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2670
    S-3.3
    LM2670SX-5.0/NOPB

    LM2670SX-5.0
    		1608.332
    1609.822
    		TO-26373
    3    		245
    235    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2670
    S-5.0
    LM2670SX-ADJ/NOPB

    LM2670SX-ADJ
    		1608.332
    1609.822
    		TO-26373
    3    		245
    235    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2670
    S-ADJ
    LM2670T-12/NOPB

    		1846.782
    		TO-22071NADetailDownloadN/A
    		NSUZXYTTE#
    LM2670
    T-12
    LM2670T-3.3/NOPB

    LM2670T-3.3
    		1846.782
    1858.793
    		TO-22071
    1    		NA
    NA    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2670
    T-3.3
    LM2670T-5.0/NOPB

    LM2670T-5.0
    		1846.782
    1858.793
    		TO-22071
    1    		NA
    NA    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2670
    T-5.0
    LM2670T-ADJ/NOPB

    LM2670T-ADJ
    		1846.782
    1858.793
    		TO-22071
    1    		NA
    NA    		DetailDownloadN/A
    		NSUZXYTTE#
    LM2670
    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 LM2670.

    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 LM2670 is located at RoHS Status.

    Reliability Metrics
    Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
    LM2670S-12LMDMOS0182950026500002751944735
    LM2670S-3.3LMDMOS0182950026500002751944735
    LM2670S-5.0LMDMOS0182950026500002751944735
    LM2670S-ADJLMDMOS0182950026500002751944735
    LM2670SD-12LMDMOS0182950026500002751944735
    LM2670SD-3.3LMDMOS0182950026500002751944735
    LM2670SD-5.0LMDMOS0182950026500002751944735
    LM2670SD-ADJLMDMOS0182950026500002751944735
    LM2670SDX-12LMDMOS0182950026500002751944735
    LM2670SDX-3.3LMDMOS0182950026500002751944735
    LM2670SDX-5.0LMDMOS0182950026500002751944735
    LM2670SDX-ADJLMDMOS0182950026500002751944735
    LM2670SX-12LMDMOS0182950026500002751944735
    LM2670SX-3.3LMDMOS0182950026500002751944735
    LM2670SX-5.0LMDMOS0182950026500002751944735
    LM2670SX-ADJLMDMOS0182950026500002751944735
    LM2670T-12LMDMOS0182950026500002751944735
    LM2670T-3.3LMDMOS0182950026500002751944735
    LM2670T-5.0LMDMOS0182950026500002751944735
    LM2670T-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 LM2670.

    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 LM2670 is located at RoHS Status.

    Obsolete Versions
    Obsolete PartAlternate Part or SupplierSourceLast Time Buy Date
    LM2670LD-12
    		NONE
    		NONE
    		30 Jan 2004
    LM2670LD-3.3
    		NONE
    		NONE
    		30 Jan 2004
    LM2670LD-5.0
    		NONE
    		NONE
    		30 Jan 2004
    LM2670LD-ADJ
    		NONE
    		NONE
    		30 Jan 2004
    LM2670LDX-12
    		NONE
    		NONE
    		30 Jan 2004
    LM2670LDX-3.3
    		NONE
    		NONE
    		30 Jan 2004
    LM2670LDX-5.0
    		NONE
    		NONE
    		30 Jan 2004
    LM2670LDX-ADJ
    		NONE
    		NONE
    		30 Jan 2004
    LM2670SX-ADJEP
    		NONE
    		NATIONAL SEMICONDUCTOR
    		16 Nov 2008

    [Information as of 9-Feb-2012]
    Copyright © 2011 National Semiconductor Corporation