National Semiconductor | High-performance Analog

 

 LM2574   
SIMPLE SWITCHER 0.5A Step-Down Voltage Regulator 		Click link to Download

Features
  • 3.3V, 5V, 12V, 15V, and adjustable output versions
  • Adjustable version output voltage range, 1.23V to 37V (57V for HV version) ±4% max over line and load conditions
  • Guaranteed 0.5A output current
  • Wide input voltage range, 40V, up to 60V for HV version
  • Requires only 4 external components
  • 52 kHz fixed frequency internal oscillator
  • TTL shutdown capability, low power standby mode
  • High efficiency
  • Uses readily available standard inductors
  • Thermal shutdown and current limit protection

    • Description

    The LM2574 series of regulators are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching regulator, capable of driving a 0.5A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5V, 12V, 15V, and an adjustable output version.

    Requiring a minimum number of external components, these regulators are simple to use and include internal frequency compensation and a fixed-frequency oscillator.

    The LM2574 series offers a high-efficiency replacement for popular three-terminal linear regulators. Because of its high efficiency, the copper traces on the printed circuit board are normally the only heat sinking needed.

    A standard series of inductors optimized for use with the LM2574 are available from several different manufacturers. This feature greatly simplifies the design of switch-mode power supplies.

    Other features include a guaranteed ±4% tolerance on output voltage within specified input voltages and output load conditions, and ±10% on the oscillator frequency. External shutdown is included, featuring 50 µA (typical) standby current. The output switch includes cycle-by-cycle current limiting, as well as thermal shutdown for full protection under fault conditions.


    Applications

  • Simple high-efficiency step-down (buck) regulator
  • Efficient pre-regulator for linear regulators
  • On-card switching regulators
  • Positive to negative converter (Buck-Boost)

    • Also Recommended
    LM25007▲Better Transient Response , Wider Switching Frequency Range
    LM25574▲42V Vin, .5A Iout, Selectable Switching Frequency
    LM2671▲260 - 400 Khz, Sync Frequency
    LM2694▲Better Transient Response , Wider Switching Frequency Range
    LM2736▲750mA, SOT23, 500Khz - 3Mhz FSW
    LM5007▲0.5A, 80V Vin, 50Khz - 800Khz FSW
    LM2594▲150Khz, Smaller Inductor



    Typical Application
    click for larger image


    		Block Diagram
    click for larger image



    Typical Performance
    *click for larger image


    Parameters / ValuesLM2574 LM25007 LM25574 LM2671 LM2694 LM2736 LM5007 LM2594
    Output Current500 mA 500 mA 500 mA 500 mA 600 mA 750 mA 500 mA 500 mA
    Input Min Voltage4 Volt 9 Volt 6 Volt 6.5 Volt 8 Volt 3 Volt 9 Volt 4.5, 7, 4.75, 15 Volt
    Input Max Voltage40 Volt 42 Volt 42 Volt 40 Volt 30 Volt 18 Volt 75 Volt 40 Volt
    Output Min3.3, 1.23, 12, 5 Volt 2.5 Volt 1.23 Volt 1.23 Volt 2.5 Volt 1.25 Volt 2.5 Volt 3.3, 1.23, 12, 5 Volt
    Output Max3.3, 37, 12, 5 Volt 37 Volt 40 Volt 37 Volt 24 Volt 16 Volt 73 Volt 3.3, 37, 12, 5 Volt
    Frequency Min52 kHz 50 kHz 50 kHz 260 kHz 50 kHz 1600, 550 kHz 50 kHz 150 kHz
    Frequency Max52 kHz 800 kHz 1000 kHz 260 kHz 1000 kHz 1600, 550 kHz 800 kHz 150 kHz
    Efficiency (peak)77, 88, 72 % 93 % 91 % 90 % 93 % 90 % 93 % 88, 80, 82 %
    On/Off PinYes Yes Yes Yes Yes Yes Yes Yes
    PowerGood / Error FlagNo No No No No No No No
    SoftStartNo No Yes Yes Yes Yes No No
    Sync PinNo No Yes Yes No No No No
    InvertingYes Yes Yes Yes No Yes Yes
    FlybackNo No No No No No No No
    RegTypeSwitching Regulator Switching Regulator Switching Regulator Switching Regulator Switching Regulator Switching Regulator Switching Regulator Switching Regulator
    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, No Yes Yes Yes Yes Yes Yes Yes, No
    Adj Switch FrequencyNo Yes Yes No Yes No Yes No
    PWM ModeVoltage Constant on-time Current Voltage with Vin Feedforward Constant on-time Current Constant on-time Voltage
    TopologyBuck Buck Buck Buck Buck Buck Buck Buck
    Special FeaturesSIMPLE SWITCHER regulator Internal startup regulator for Vin>9V, internal 42V/07A N-FET, Pull Ron pin to ground for shutdown 1.5% feedback voltage accuracy, emulated current mode Internal Type 3 compensation, 1.5% output voltage accuracy, SIMPLE SWITCHER regulator No compensation required, ultra-fast transient response OVP, internal compensation Internal startup regulator for Vin>9V, internal 80V/0.7A N-FET, Pull Ron pin to ground for shutdown SIMPLE SWITCHER regulator
    Step-DownYes Yes Yes Yes Yes Yes Yes Yes
    Multiple Output CapabilityNo No No No No No No No
    Output PowerUndefined Watt Undefined Watt Undefined Watt Undefined Watt Undefined Watt Undefined Watt Undefined Watt
    Output Voltage3.3, Undefined, 12, 5 Volt Undefined Volt Undefined Volt Undefined Volt Undefined Volt Undefined Volt Undefined Volt 3.3, Undefined, 12, 5 Volt
    Output Range5V, 12V, 1.23V to 37V, 3.3V 2.5V to 37V 1.23V to 37V 1.23V to 37V 2.5V to 24V 1.25V to 13V 2.5V to 73V 5V, 12V, 1.23V to 37V, 3.3V
    Switching Frequency52 kHz 800 kHz 1000 kHz 260 kHz 1000 kHz 1600, 550 kHz 800 kHz 150 kHz
    Regulator FamilySIMPLE SWITCHER Undefined SIMPLE SWITCHER SIMPLE SWITCHER Undefined Undefined Undefined SIMPLE SWITCHER
    Synchronous RectificationNo No No No No No No No

    Datasheets
    TitleSizeDateOther
    Language
    LM2574 SIMPLE SWITCHER 0.5A Step-Down Voltage Regulator639
    Kbytes    		30-Jun-99日本語  


    Other Technical Documents
    TitleTypeDate
    Buck Converters Provide a Battery Charger and System PowerApp Note 2007-03-21

    Part Number(s)
    (NSID)    		Top ViewAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM2574M-12/NOPB

    LM2574M-12

    RoHS Status

    SOIC WIDE    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide673
    FARNELLEurope and Asia908
    MOUSERWorldwide400
    NEWARKAmericas85
    		$0.84 each at 1K+ pcsrail
    of
    50
    LM2574M-3.3/NOPB

    LM2574M-3.3

    RoHS Status

    SOIC WIDE    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide391
    AVNET-EMWorldwide438
    DIGI-KEYWorldwide2377
    MOUSERWorldwide431
    NEWARKAmericas148
    TAYLORAmericas391
    		$0.84 each at 1K+ pcsrail
    of
    50
    LM2574M-5.0/NOPB

    LM2574M-5.0

    RoHS Status

    SOIC WIDE    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide2169
    AVNET-EMWorldwide3210
    DIGI-KEYWorldwide2011
    MOUSERWorldwide173
    NEWARKAmericas438
    RS COMPONENTSWorldwide224
    TAYLORAmericas2169
    		$0.84 each at 1K+ pcsrail
    of
    50
    LM2574M-ADJ/NOPB

    LM2574M-ADJ

    RoHS Status

    SOIC WIDE    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide1
    DIGI-KEYWorldwide0
    FARNELLEurope and Asia785
    MOUSERWorldwide900
    NEWARKAmericas309
    TAYLORAmericas1
    		$0.84 each at 1K+ pcsrail
    of
    50
    LM2574MX-12/NOPB

    LM2574MX-12

    RoHS Status

    SOIC WIDE    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    MOUSERWorldwide1000
    		$0.84 each at 1K+ pcsreel
    of
    1000
    LM2574MX-3.3/NOPB

    LM2574MX-3.3

    RoHS Status

    SOIC WIDE    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    AVNET-EMWorldwide1000
    DIGI-KEYWorldwide0
    MOUSERWorldwide1000
    TECHMOSAAsia Pacific5000
    		$0.84 each at 1K+ pcsreel
    of
    1000
    LM2574MX-5.0/NOPB

    LM2574MX-5.0

    RoHS Status

    SOIC WIDE    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    ARROWWorldwide3357
    AVNET-EMWorldwide5000
    DIGI-KEYWorldwide0
    MOUSERWorldwide913
    RSL MICROAsia Pacific2000
    TAYLORAmericas3357
    		$0.84 each at 1K+ pcsreel
    of
    1000
    LM2574MX-ADJ/NOPB

    LM2574MX-ADJ

    RoHS Status

    SOIC WIDE    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    ARROWWorldwide1275
    DIGI-KEYWorldwide1000
    MOUSERWorldwide840
    RSL MICROAsia Pacific6000
    TAYLORAmericas1275
    		$0.84 each at 1K+ pcsreel
    of
    1000
    LM2574N-12/NOPB

    LM2574N-12

    RoHS Status

    MDIP    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide454
    AVNET-EMWorldwide402
    DIGI-KEYWorldwide102
    FARNELLEurope and Asia423
    MOUSERWorldwide75
    NEWARKAmericas109
    RS COMPONENTSWorldwide287
    TAYLORAmericas1184
    		$0.80 each at 1K+ pcsrail
    of
    40
    LM2574N-3.3/NOPB

    LM2574N-3.3

    RoHS Status

    MDIP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    MOUSERWorldwide478
    		$0.80 each at 1K+ pcsrail
    of
    40
    LM2574N-5.0/NOPB

    LM2574N-5.0

    RoHS Status

    MDIP    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide240
    AVNET-EMWorldwide473
    DIGI-KEYWorldwide1020
    MOUSERWorldwide365
    NEWARKAmericas349
    RS COMPONENTSWorldwide556
    RSL MICROAsia Pacific10000
    TAYLORAmericas240
    		$0.80 each at 1K+ pcsrail
    of
    40
    LM2574N-ADJ/NOPB

    LM2574N-ADJ

    RoHS Status

    MDIP    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide68
    DIGI-KEYWorldwide1338
    FARNELLEurope and Asia2004
    MOUSERWorldwide468
    NEWARKAmericas36
    RS COMPONENTSWorldwide348
    RSL MICROAsia Pacific5000
    TAYLORAmericas2903
    		$0.80 each at 1K+ pcsrail
    of
    40

    Obsolete Versions
    Obsolete PartAlternate Part or SupplierSourceLast Time Buy Date
    LM2574-5.0 MDA
    		NONE
    		NATIONAL SEMICONDUCTOR
    		03 Dec 2008
    LM2574-5.0 MWA
    		LM5574 MWC
    		NATIONAL SEMICONDUCTOR
    		03 Dec 2008
    LM2574HV-12 MWC
    		LM5574 MWC
    		NAITONAL SEMICONDUCTOR
    		03 Dec 2008
    LM2574HV-15 MWC
    		LM5574 MWC
    		NATIONAL SEMICONDUCTOR
    		03 Dec 2008
    LM2574HV-5 MDC
    		LM5574 MDC
    		NATIONAL SEMICONDUCTOR
    		03 Dec 2008
    LM2574HV-5 MWC
    		LM5574 MWC
    		NATIONAL SEMICONDUCTOR
    		03 Dec 2008
    LM2574HV3.3 MDC
    		LM5574 MDC
    		NATIONAL SEMICONDUCTOR
    		03 Dec 2008
    LM2574HV3.3 MWC
    		LM5574 MWC
    		NATIONAL SEMICONDUCTOR
    		03 Dec 2008
    LM2574HVN-3.3
    		LM2574HVN-5.0
    		NATIONAL SEMICONDUCTOR
    		01 Dec 2009
    LM2574M-15
    		LM2574M-ADJ
    		NATIONAL SEMICONDUCTOR
    		16 Nov 2008
    LM2574MX-15
    		LM2574M-ADJ
    		NATIONAL SEMICONDUCTOR
    		16 Nov 2008
    LM2574N-15
    		LM2574N-ADJ
    		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 LM2574.

    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 LM2574 is located at RoHS Status.

    Part Number(s)
    (NSID)    		Weight
    (milligrams)    		TypePinsMSL RatingPeak ReflowRoHS
    Status    		CAD SymbolsModelsPackage
    Marking
    Format
    LM2574M-12/NOPB

    LM2574M-12
    		359.279
    359.999
    		SOIC WIDE143
    2A    		260
    220    		DetailN/AN/A
    		NSUZXYTTE#
    LM2574M
    -12 P+
    LM2574M-3.3/NOPB

    LM2574M-3.3
    		359.279
    359.999
    		SOIC WIDE143
    2A    		260
    220    		DetailN/AN/A
    		NSUZXYTTE#
    LM2574M
    -3.3 P+
    LM2574M-5.0/NOPB

    LM2574M-5.0
    		359.279
    359.999
    		SOIC WIDE143
    2A    		260
    220    		DetailN/AN/A
    		NSUZXYTTE#
    LM2574M
    -5.0 P+
    LM2574M-ADJ/NOPB

    LM2574M-ADJ
    		359.279
    359.999
    		SOIC WIDE143
    2A    		260
    220    		DetailN/AN/A
    		NSUZXYTTE#
    LM2574M
    -ADJ P+
    LM2574MX-12/NOPB

    LM2574MX-12
    		359.279
    359.999
    		SOIC WIDE143
    2A    		260
    220    		DetailN/AN/A
    		NSUZXYTTE#
    LM2574M
    -12 P+
    LM2574MX-3.3/NOPB

    LM2574MX-3.3
    		359.279
    359.999
    		SOIC WIDE144
    2A    		260
    220    		DetailN/AN/A
    		NSUZXYTTE#
    LM2574M
    -3.3 P+
    LM2574MX-5.0/NOPB

    LM2574MX-5.0
    		359.279
    359.999
    		SOIC WIDE143
    2A    		260
    220    		DetailN/AN/A
    		NSUZXYTTE#
    LM2574M
    -5.0 P+
    LM2574MX-ADJ/NOPB

    LM2574MX-ADJ
    		359.279
    359.999
    		SOIC WIDE143
    2A    		260
    220    		DetailN/AN/A
    		NSUZXYTTE#
    LM2574M
    -ADJ P+
    LM2574N-12/NOPB

    LM2574N-12
    		508.252
    510.002
    		MDIP81
    1    		NA
    NA    		DetailN/AN/A
    		NSUZXYTTE#
    LM2574N
    -12 P+
    LM2574N-3.3/NOPB

    LM2574N-3.3
    		508.252
    510.002
    		MDIP81
    1    		NA
    NA    		DetailN/AN/A
    		NSUZXYTTE#
    LM2574N
    -3.3 P+
    LM2574N-5.0/NOPB

    LM2574N-5.0
    		508.252
    510.002
    		MDIP81
    1    		NA
    NA    		DetailN/AN/A
    		NSUZXYTTE#
    LM2574N
    -5.0 P+
    LM2574N-ADJ/NOPB

    LM2574N-ADJ
    		508.252
    510.002
    		MDIP81
    1    		NA
    NA    		DetailN/AN/A
    		NSUZXYTTE#
    LM2574N
    -ADJ P+

    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 LM2574.

    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 LM2574 is located at RoHS Status.

    Design Tools
    TitleSizeDate
    SimpleSwitcher® DC-DC Converters Design Software  

    CAD Symbols and Models
    N/A
    		 Models
    N/A


    Reliability Metrics
    Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
    LM2574M-12SLM04404600353250011002356520
    LM2574M-3.3SLM04404600353250011002356520
    LM2574M-5.0SLM04404600353250011002356520
    LM2574M-ADJSLM04404600353250011002356520
    LM2574MX-12SLM04404600353250011002356520
    LM2574MX-3.3SLM04404600353250011002356520
    LM2574MX-5.0SLM04404600353250011002356520
    LM2574MX-ADJSLM04404600353250011002356520
    LM2574N-12SLM04404600353250011002356520
    LM2574N-3.3SLM04404600353250011002356520
    LM2574N-5.0SLM04404600353250011002356520
    LM2574N-ADJSLM04404600353250011002356520

    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 LM2574.

    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 LM2574 is located at RoHS Status.

    Obsolete Versions
    Obsolete PartAlternate Part or SupplierSourceLast Time Buy Date
    LM2574-5.0 MDA
    		NONE
    		NATIONAL SEMICONDUCTOR
    		03 Dec 2008
    LM2574-5.0 MWA
    		LM5574 MWC
    		NATIONAL SEMICONDUCTOR
    		03 Dec 2008
    LM2574HV-12 MWC
    		LM5574 MWC
    		NAITONAL SEMICONDUCTOR
    		03 Dec 2008
    LM2574HV-15 MWC
    		LM5574 MWC
    		NATIONAL SEMICONDUCTOR
    		03 Dec 2008
    LM2574HV-5 MDC
    		LM5574 MDC
    		NATIONAL SEMICONDUCTOR
    		03 Dec 2008
    LM2574HV-5 MWC
    		LM5574 MWC
    		NATIONAL SEMICONDUCTOR
    		03 Dec 2008
    LM2574HV3.3 MDC
    		LM5574 MDC
    		NATIONAL SEMICONDUCTOR
    		03 Dec 2008
    LM2574HV3.3 MWC
    		LM5574 MWC
    		NATIONAL SEMICONDUCTOR
    		03 Dec 2008
    LM2574HVN-3.3
    		LM2574HVN-5.0
    		NATIONAL SEMICONDUCTOR
    		01 Dec 2009
    LM2574M-15
    		LM2574M-ADJ
    		NATIONAL SEMICONDUCTOR
    		16 Nov 2008
    LM2574MX-15
    		LM2574M-ADJ
    		NATIONAL SEMICONDUCTOR
    		16 Nov 2008
    LM2574N-15
    		LM2574N-ADJ
    		NATIONAL SEMICONDUCTOR
    		16 Nov 2008

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