National Semiconductor | High-performance Analog

 

 LM5085   
75V Constant On-Time PFET Buck Switching Controller from the PowerWise® Family		 Click link to Download

Features

  • LM5085Q is an Automotive Grade product that is AEC-Q100 grade 1 qualified (-40°C to 125°C operating junction temperature)
  • Wide 4.5V to 75V input voltage range
  • Adjustable current limit using RDS(ON) or a current sense resistor
  • Programmable switching frequency to 1MHz
  • No loop compensation required
  • Ultra-Fast transient response
  • Nearly constant operating frequency with line and load variations
  • Adjustable output voltage from 1.25V
  • Precision ±2% feedback reference
  • Capable of 100% duty cycle operation
  • Internal soft-start timer
  • Integrated high voltage bias regulator
  • Thermal shutdown

    • Description

    The LM5085 is a high efficiency PFET switching regulator controller that can be used to quickly and easily develop a small, efficient buck regulator for a wide range of applications. This high voltage controller contains a PFET gate driver and a high voltage bias regulator which operates over a wide 4.5V to 75V input range. The constant on-time regulation principle requires no loop compensation, simplifies circuit implementation, and results in ultra-fast load transient response. The operating frequency remains nearly constant with line and load variations due to the inverse relationship between the input voltage and the on-time. The PFET architecture allows 100% duty cycle operation for a low dropout voltage. Either the RDS(ON) of the PFET or an external sense resistor can be used to sense current for over-current detection.

    WEBENCH® LM5085
        Min   Max   Range  
      VIN – V    4.50 – 75.00V  
      VOUT V    1.25 – 75.00V  
      IOUT A    ≤ 10.00A  
      Ambient Temp °C    ≤ 100°C  
    Footprint BOM Cost Efficiency
    What are WEBENCH® tools?


    Also Recommended
    LM25085▲VIN 4.5V To 42V
    LM25085A▲VIN 4.5V To 42V And Lower 0.9V Reference Voltage



    Typical Application
    click for larger image


    		Block Diagram
    click for larger image



    Typical Performance
    *click for larger image


    Parameters / ValuesLM5085 LM25085 LM25085A
    Input Min Voltage4.5 Volt 4.5 Volt 4.5 Volt
    Input Max Voltage75 Volt 42 Volt 42 Volt
    Output Range1.25V to VIN 1.25V to VIN 0.9V to VIN
    Frequency Max1000 kHz 1000 kHz 1000 kHz
    Feedback Voltage1.25 Volt 1.25 Volt 0.9 Volt
    Feedback Tolerance2 % 2 % 2 %
    Efficiency (peak)95 % 95 %
    Adj Switch FrequencyYes Yes Yes
    Adjustable OutputYes Yes Yes
    Synchronous RectificationNo No No
    On/Off PinYes Yes Yes
    PowerGood / Error FlagNo No No
    SoftStartYes Yes Yes
    Sync PinNo No No
    InvertingYes Yes Yes
    FlybackNo No No
    RegTypeSwitching Controller Switching Controller Switching Controller
    Temperature Min-40 deg C -40 deg C -40 deg C
    Temperature Max125 deg C 125 deg C 125 deg C
    Channels1 Channels 1 Channels
    Special FeaturesNear constant switching frequency, PFET for 100% duty cycle Near constant switching frequency, PFET for 100% duty cycle Near constant switching frequency, PFET for 100% duty cycle
    TopologyBuck Buck Buck
    PWM ModeConstant On-Time (COT) Constant On-Time (COT) Constant On-Time (COT)
    Step-DownYes Yes Yes
    Step-UpNo No
    AEC Q-100 Automotive Grade1 1
    AutomotiveYes No No
    PowerWiseYes Yes No

    Datasheets
    TitleSizeDateOther
    Language
    LM5085 75V Constant On-Time PFET Buck Switching Controller489
    Kbytes    		17-Dec-09   


    Application Notes
    TitleSizeDateOther
    Language
    AN-1878: Application Note 1878 LM5085 Evaluation Board359
    Kbytes    		13-Nov-08 
    AN-2157: Application Note 2157 Constant Current Constant Voltage Buck Converter with LM25085, or, Implementing Accurate Current Limit with LM25085447
    Kbytes    		21-Jun-11 


    Other Technical Documents
    TitleTypeDate
    Designing Non-Inverting Buck-Boost (Zeta) Converters with a Buck P-FET ControllerPower Designer 2011-04-22

    Part Number(s)
    (NSID)    		Top ViewAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM5085MM/NOPB


    RoHS Status

    MINI SOIC    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    AVNET-EMWorldwide1000
    DIGI-KEYWorldwide0
    		$1.00 each at 1K+ pcsreel
    of
    1000
    LM5085MME/NOPB


    RoHS Status

    MINI SOIC    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide500
    AVNET-EMWorldwide250
    DIGI-KEYWorldwide1345
    FARNELLEurope and Asia688
    MOUSERWorldwide418
    NEWARKAmericas94
    TAYLORAmericas500
    		$1.00 each at 1K+ pcsreel
    of
    250
    LM5085MMX/NOPB


    RoHS Status

    MINI SOIC    		Full production
    Lead Time: 8 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.00 each at 1K+ pcsreel
    of
    3500
    LM5085MY/NOPB


    RoHS Status

    MINI SOIC EXP PAD    		Full production
    Lead Time: 12 weeks

     
    DistributorRegionQty
    ARROWWorldwide5000
    DIGI-KEYWorldwide0
    MOUSERWorldwide865
    TAYLORAmericas5000
    		$1.00 each at 1K+ pcsreel
    of
    1000
    LM5085MYE/NOPB


    RoHS Status

    MINI SOIC EXP PAD    		Full production
    Lead Time: 12 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide500
    AVNET-EMWorldwide250
    DIGI-KEYWorldwide533
    FARNELLEurope and Asia1010
    MOUSERWorldwide135
    TAYLORAmericas582
    		$1.00 each at 1K+ pcsreel
    of
    250
    LM5085MYX/NOPB


    RoHS Status

    MINI SOIC EXP PAD    		Full production
    Lead Time: 12 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.00 each at 1K+ pcsreel
    of
    3500
    LM5085QMY/NOPB

    Auto Grade 1
    RoHS Status

    MINI SOIC EXP PAD    		Full production
    Lead Time: 8 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.15 each at 1K+ pcsreel
    of
    1000
    LM5085QMYE/NOPB

    Auto Grade 1
    RoHS Status

    MINI SOIC EXP PAD    		Full production
    Lead Time: 8 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide500
    AVNET-EMWorldwide250
    DIGI-KEYWorldwide617
    FARNELLEurope and Asia36
    MOUSERWorldwide68
    NEWARKAmericas36
    TAYLORAmericas500
    		$1.15 each at 1K+ pcsreel
    of
    250
    LM5085QMYX/NOPB

    Auto Grade 1
    RoHS Status

    MINI SOIC EXP PAD    		Full production
    Lead Time: 12 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.15 each at 1K+ pcsreel
    of
    3500
    LM5085SD/NOPB


    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.00 each at 1K+ pcsreel
    of
    1000
    LM5085SDE/NOPB


    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    AVNET-EMWorldwide2750
    DIGI-KEYWorldwide552
    FARNELLEurope and Asia355
    MOUSERWorldwide320
    NEWARKAmericas355
    		$1.00 each at 1K+ pcsreel
    of
    250
    LM5085SDX/NOPB


    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.00 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 LM5085.

    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 LM5085 is located at RoHS Status.

    Part Number(s)
    (NSID)    		DescriptionAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM5085EVAL/NOPB

    		LM5085 - 75V Constant On-Time PFET Buck Switching ControllerFull production
    Lead Free (RoHS)

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$70.00 each1

    Description:

    The LM5085 evaluation board provides the design engineer with a fully functional buck regulator, employing the LM5085 PFET switching controller which uses the constant on-time (COT) operating principle. The evaluation board provides a 5V output over an input range of 5.5V to 55V. The circuit delivers load currents to 4.5A, with current limit set at ≅7.6A. The board is populated with all components except C5.

    Features:

    • Input Voltage: 5.5V to 55V, 60V maximum
    • Output Voltage: 5V
    • Maximum load current: 4.5A for VIN >8V
    • Minimum load current: 0A
    • Current Limit Threshold: ≅7.6A
    • Measured Efficiency: 97.2% (VIN 5.5V, IOUT = 0.6Amps)
    • Nominal Switching Frequency: 300 kHz
    • Size: 3.1 in. x 1.5 in. x 0.78 in

    Contents:




    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
    LM5085MM/NOPB

    		29.851
    30.002
    		MINI SOIC81260DetailDownloadN/A
    		ZXTT
    SSTB
    LM5085MME/NOPB

    		29.851
    		MINI SOIC81260DetailDownloadN/A
    		ZXTT
    SSTB
    LM5085MMX/NOPB

    		29.851
    30.002
    		MINI SOIC81260DetailDownloadN/A
    		ZXTT
    SSTB
    LM5085MY/NOPB

    		29.851
    30.002
    		MINI SOIC EXP PAD81260DetailDownloadN/A
    		ZXTT
    SSSB
    LM5085MYE/NOPB

    		29.851
    		MINI SOIC EXP PAD81260DetailDownloadN/A
    		ZXTT
    SSSB
    LM5085MYX/NOPB

    		29.851
    30.002
    		MINI SOIC EXP PAD81260DetailDownloadN/A
    		ZXTT
    SSSB
    LM5085QMY/NOPB

    		29.851
    		MINI SOIC EXP PAD81260DetailDownloadN/A
    		ZXTT
    SYCB
    LM5085QMYE/NOPB

    		29.851
    		MINI SOIC EXP PAD81260DetailDownloadN/A
    		ZXTT
    SYCB
    LM5085QMYX/NOPB

    		29.851
    		MINI SOIC EXP PAD81260DetailDownloadN/A
    		ZXTT
    SYCB
    LM5085SD/NOPB

    		20.736
    		LLP81260DetailDownloadN/A
    		ZXYTT
    L245B
    LM5085SDE/NOPB

    		20.736
    		LLP81260DetailDownloadN/A
    		ZXYTT
    L245B
    LM5085SDX/NOPB

    		20.736
    		LLP81260DetailDownloadN/A
    		ZXYTT
    L245B

    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 LM5085.

    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 LM5085 is located at RoHS Status.

    Design Tools
    TitleSizeDate
    LM(2)5085 Quick Start Calculator  

    CAD Symbols and Models
    Download LM5085 CAD Symbols
    		 Models
    N/A


    Reliability Metrics
    Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
    LM5085MMABCD150XV1038680025950002736338335
    LM5085MMEABCD150XV1038680025950002736338335
    LM5085MMXABCD150XV1038680025950002736338335
    LM5085MYABCD150XV1038680025950002736338335
    LM5085MYEABCD150XV1038680025950002736338335
    LM5085MYXABCD150XV1038680025950002736338335
    LM5085QMYABCD150XV1038680025950002736338335
    LM5085QMYEABCD150XV1038680025950002736338335
    LM5085QMYXABCD150XV1038680025950002736338335
    LM5085SDABCD150XV1038680025950002736338335
    LM5085SDEABCD150XV1038680025950002736338335
    LM5085SDXABCD150XV1038680025950002736338335

    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 LM5085.

    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 LM5085 is located at RoHS Status.

    What's New in Power -- January 2009
    Loading video...


    What's New in Power Management -- October 09
    Loading video...


    LM25085/5085 Implementing Accurate Current Limit Demo
    Loading video...


    What's New in Power -- January 2009
    Date: 2009-01-19
    Length: 0:04:57
    What's New in Power Management -- October 09
    Date: 2009-10-30
    Length: 0:04:02
    LM25085/5085 Implementing Accurate Current Limit Demo
    Date: 2011-07-29
    Length: 00:03:24
    [Information as of 8-Feb-2012]
    Copyright © 2011 National Semiconductor Corporation