National Semiconductor | High-performance Analog

 

 LM25085   
42V Constant On-Time PFET Buck Switching Controller from the PowerWise® Family		 Click link to Download

Features

  • LM25085Q is an Automotive Grade product that is AEC-Q100 grade 1 qualified (-40°C to 125°C operating junction temperature)
  • Wide 4.5V to 42V 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 LM25085 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 42V 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® LM25085
        Min   Max   Range  
      VIN – V    4.50 – 42.00V  
      VOUT V    1.25 – 42.00V  
      IOUT A    ≤ 10.00A  
      Ambient Temp °C    ≤ 100°C  
    Footprint BOM Cost Efficiency
    What are WEBENCH® tools?


    Also Recommended
    LM25085A▲Lower 0.9V Reference Voltage
    LM5085▲Higher VIN Up To 75V



    Typical Application
    click for larger image


    		Block Diagram
    click for larger image



    Typical Performance
    *click for larger image


    Parameters / ValuesLM25085 LM25085A LM5085
    Input Min Voltage4.5 Volt 4.5 Volt 4.5 Volt
    Input Max Voltage42 Volt 42 Volt 75 Volt
    Output Range1.25V to VIN 0.9V to VIN 1.25V to VIN
    Frequency Max1000 kHz 1000 kHz 1000 kHz
    Feedback Voltage1.25 Volt 0.9 Volt 1.25 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
    Lossless Current SenseNo 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
    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
    Output Min1.25 Volt 0.9 Volt
    AEC Q-100 Automotive Grade1 1
    AutomotiveNo No Yes
    PowerWiseYes No Yes
    Part Number(s)
    (NSID)    		Top ViewAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM25085MM/NOPB


    RoHS Status

    MINI SOIC    		Full production
    Lead Time: 12 weeks

     
    DistributorRegionQty
    AVNET-EMWorldwide1000
    DIGI-KEYWorldwide3410
    MOUSERWorldwide945
    		$0.79 each at 1K+ pcsreel
    of
    1000
    LM25085MME/NOPB


    RoHS Status

    MINI SOIC    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide475
    FARNELLEurope and Asia492
    MOUSERWorldwide400
    NEWARKAmericas168
    		$0.79 each at 1K+ pcsreel
    of
    250
    LM25085MMX/NOPB


    RoHS Status

    MINI SOIC    		Full production
    Lead Time: 8 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$0.79 each at 1K+ pcsreel
    of
    3500
    LM25085MY/NOPB


    RoHS Status

    MINI SOIC EXP PAD    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    CEACAsia Pacific4000
    DIGI-KEYWorldwide0
    MOUSERWorldwide878
    		$0.79 each at 1K+ pcsreel
    of
    1000
    LM25085MYE/NOPB


    RoHS Status

    MINI SOIC EXP PAD    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide128
    AVNET-EMWorldwide250
    DIGI-KEYWorldwide439
    FARNELLEurope and Asia48
    MOUSERWorldwide485
    NEWARKAmericas38
    TAYLORAmericas128
    		$0.79 each at 1K+ pcsreel
    of
    250
    LM25085MYX/NOPB


    RoHS Status

    MINI SOIC EXP PAD    		Full production
    Lead Time: 8 weeks

     
    DistributorRegionQty
    AVNET-EMWorldwide3500
    DIGI-KEYWorldwide0
    		$0.79 each at 1K+ pcsreel
    of
    3500
    LM25085QMY/NOPB

    Auto Grade 1
    RoHS Status

    MINI SOIC EXP PAD    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$0.91 each at 1K+ pcsreel
    of
    1000
    LM25085QMYE/NOPB

    Auto Grade 1
    RoHS Status

    MINI SOIC EXP PAD    		Full production
    Lead Time: 12 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide782
    MOUSERWorldwide500
    		$0.91 each at 1K+ pcsreel
    of
    250
    LM25085QMYX/NOPB

    Auto Grade 1
    RoHS Status

    MINI SOIC EXP PAD    		Full production
    Lead Time: 12 weeks

     
    DistributorRegionQty
    ARROWWorldwide3500
    DIGI-KEYWorldwide0
    MOUSERWorldwide3500
    TAYLORAmericas3500
    		$0.91 each at 1K+ pcsreel
    of
    3500
    LM25085SD/NOPB


    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$0.79 each at 1K+ pcsreel
    of
    1000
    LM25085SDE/NOPB


    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide359
    MOUSERWorldwide500
    		$0.79 each at 1K+ pcsreel
    of
    250
    LM25085SDX/NOPB


    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$0.79 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 LM25085.

    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 LM25085 is located at RoHS Status.

    Part Number(s)
    (NSID)    		DescriptionAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM25085MYEVAL/NOPB

    		Evaluation Board for LM25085 - 42V Constant On-Time PFET Buck Switching ControllerFull production
    Lead Free (RoHS)

     
    DistributorRegionQty
    AVNET-EMWorldwide2
    DIGI-KEYWorldwide0
    MOUSERWorldwide2
    		$70.00 each1

    Description:

    The LM25085 evaluation board provides the design engineer with a fully functional buck regulator, employing the LM25085 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 42V. The circuit delivers load currents to 5A, with current limit set at ≅8.2A. The board is populated with all components except C5.

    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
    LM25085MM/NOPB

    		29.851
    		MINI SOIC81260DetailDownloadN/A
    		ZXTT
    SVZB
    LM25085MME/NOPB

    		29.851
    		MINI SOIC81260DetailDownloadN/A
    		ZXTT
    SVZB
    LM25085MMX/NOPB

    		29.851
    		MINI SOIC81260DetailDownloadN/A
    		ZXTT
    SVZB
    LM25085MY/NOPB

    		29.851
    		MINI SOIC EXP PAD81260DetailDownloadN/A
    		ZXTT
    SVYB
    LM25085MYE/NOPB

    		29.851
    		MINI SOIC EXP PAD81260DetailDownloadN/A
    		ZXTT
    SVYB
    LM25085MYX/NOPB

    		29.851
    		MINI SOIC EXP PAD81260DetailDownloadN/A
    		ZXTT
    SVYB
    LM25085QMY/NOPB

    		29.851
    		MINI SOIC EXP PAD81260DetailDownloadN/A
    		ZXTT
    SYLB
    LM25085QMYE/NOPB

    		29.851
    		MINI SOIC EXP PAD81260DetailDownloadN/A
    		ZXTT
    SYLB
    LM25085QMYX/NOPB

    		29.851
    		MINI SOIC EXP PAD81260DetailDownloadN/A
    		ZXTT
    SYLB
    LM25085SD/NOPB

    		20.736
    		LLP81260DetailDownloadN/A
    		ZXYTT
    L246B
    LM25085SDE/NOPB

    		20.736
    		LLP81260DetailDownloadN/A
    		ZXYTT
    L246B
    LM25085SDX/NOPB

    		20.736
    		LLP81260DetailDownloadN/A
    		ZXYTT
    L246B

    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 LM25085.

    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 LM25085 is located at RoHS Status.

    Design Tools
    TitleSizeDate
    LM(2)5085 Quick Start Calculator  

    CAD Symbols and Models
    Download LM25085 CAD Symbols
    		 Models
    N/A


    Reliability Metrics
    Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
    LM25085MMABCD150XV1038680025950002736338335
    LM25085MMEABCD150XV1038680025950002736338335
    LM25085MMXABCD150XV1038680025950002736338335
    LM25085MYABCD150XV1038680025950002736338335
    LM25085MYEABCD150XV1038680025950002736338335
    LM25085MYXABCD150XV1038680025950002736338335
    LM25085QMYABCD150XV1038680025950002736338335
    LM25085QMYEABCD150XV1038680025950002736338335
    LM25085QMYXABCD150XV1038680025950002736338335
    LM25085SDABCD150XV1038680025950002736338335
    LM25085SDEABCD150XV1038680025950002736338335
    LM25085SDXABCD150XV1038680025950002736338335

    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 LM25085.

    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 LM25085 is located at RoHS Status.

    What's New in Power -- January 2009
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    What's New in Power Management -- October 09
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    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