National Semiconductor | High-performance Analog

 

 LM3502   
Step-Up Converter for White LED Applications from the PowerWise® Family		 Click link to Download

Features
  • Drive up to 4, 6, 8 or 10 white LEDs for Dual Display Backlighting
  • >80% efficiency
  • Output Voltage Options: 16V , 25V , 35V, and 44V
  • Input Under-Voltage Protection
  • Internal Soft Start Eliminating Inrush Current
  • 1 MHz Constant Switching Frequency
  • Wide Input Voltage: 2.5V to 5.5V
  • Small External Components
  • Low Profile Packages: <1 mm Height -10 Bump MicroSMD -16 Pin LLP

    • Description

    The LM3502 is a white LED driver for lighting applications. For dual display or large single white LED string backlighting applications, the LM3502 provides a complete solution. The LM3502 contains two internal white LED current bypass FET(Field Effect Transitor) switches that are ideal for controlling dual display applications. The white LED current can be adjusted with a PWM signal directly from a microcontroller without the need of an RC filter network.

    With no external compensation, cycle-by-cycle current limit, over-voltage protection, and under-voltage protection, the LM3502 offers superior performance over other application specific standard product step-up white LED drivers.


    Applications

  • Dual Display Backlighting in Portable Devices
  • Cellular Phones and PDAs




    • Typical Application
    click for larger image


    		Block Diagram
    click for larger image



    Typical Performance
    click for larger image


     

    ParametersValues
    Regulated LEDs 10
    Boost Type Inductive
    Switching Frequency 1000 kHz
    Efficiency (peak) 80 %
    Input Min Voltage 2.5 Volt
    Input Max Voltage 5.5 Volt
    OutputMax Voltage 35, 16, 44, 25 Volt
    Special Features Dual display control
    PWM BrightCtrl No
    Analog-V BrightCtrl No
    Ambient Light Compensation No
    RGB-LED No
    Temperature Min -40 deg C
    Temperature Max 125 deg C
    RegType Switching Regulator
    PowerWise Yes

    Datasheets
    TitleSizeDateOther
    Language
    LM3502 Step-Up Converter for White LED Applications928
    Kbytes    		30-Aug-06   


    Application Notes
    TitleSizeDateOther
    Language
    AN-1407: Application Note 1407 LM3502/03 Evaluation Board519
    Kbytes    		18-Jul-06 中文

    Part Number(s)
    (NSID)    		Top ViewAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM3502ITL-16/NOPB


    RoHS Status

    MICRO SMD    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide0
    FARNELLEurope and Asia239
    MOUSERWorldwide250
    NEWARKAmericas239
    		$1.10 each at 1K+ pcsreel
    of
    250
    LM3502ITL-25/NOPB


    RoHS Status

    MICRO SMD    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide0
    FARNELLEurope and Asia240
    MOUSERWorldwide250
    NEWARKAmericas240
    RS COMPONENTSWorldwide145
    		$1.10 each at 1K+ pcsreel
    of
    250
    LM3502ITL-35/NOPB


    RoHS Status

    MICRO SMD    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    FARNELLEurope and Asia250
    MOUSERWorldwide250
    NEWARKAmericas250
    		$1.10 each at 1K+ pcsreel
    of
    250
    LM3502ITL-44/NOPB


    RoHS Status

    MICRO SMD    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide0
    FARNELLEurope and Asia238
    MOUSERWorldwide250
    NEWARKAmericas238
    RS COMPONENTSWorldwide1250
    		$1.10 each at 1K+ pcsreel
    of
    250
    LM3502ITLX-16/NOPB


    RoHS Status

    MICRO SMD    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.10 each at 1K+ pcsreel
    of
    3000
    LM3502ITLX-25/NOPB


    RoHS Status

    MICRO SMD    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.10 each at 1K+ pcsreel
    of
    3000
    LM3502ITLX-35/NOPB


    RoHS Status

    MICRO SMD    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.10 each at 1K+ pcsreel
    of
    3000
    LM3502ITLX-44/NOPB


    RoHS Status

    MICRO SMD    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.10 each at 1K+ pcsreel
    of
    3000
    LM3502SQ-16/NOPB

    LM3502SQ-16

    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide1000
    DIGI-KEYWorldwide0
    MOUSERWorldwide904
    TAYLORAmericas1000
    		$1.10 each at 1K+ pcsreel
    of
    1000
    LM3502SQ-25/NOPB

    LM3502SQ-25

    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide1000
    FARNELLEurope and Asia37
    MOUSERWorldwide1000
    		$1.10 each at 1K+ pcsreel
    of
    1000
    LM3502SQ-35/NOPB

    LM3502SQ-35

    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide0
    FARNELLEurope and Asia20
    MOUSERWorldwide1000
    		$1.10 each at 1K+ pcsreel
    of
    1000
    LM3502SQ-44/NOPB

    LM3502SQ-44

    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide0
    MOUSERWorldwide1000
    		$1.10 each at 1K+ pcsreel
    of
    1000
    LM3502SQX-16/NOPB

    LM3502SQX-16

    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.10 each at 1K+ pcsreel
    of
    4500
    LM3502SQX-25/NOPB

    LM3502SQX-25

    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.10 each at 1K+ pcsreel
    of
    4500
    LM3502SQX-35/NOPB

    LM3502SQX-35

    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.10 each at 1K+ pcsreel
    of
    4500
    LM3502SQX-44/NOPB

    LM3502SQX-44

    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$1.10 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 LM3502.

    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 LM3502 is located at RoHS Status.

    Part Number(s)
    (NSID)    		DescriptionAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM3502ITL-44EV
    		Step-Up Converter for White LED ApplicationsFull production


     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    FARNELLEurope and Asia1
    NEWARKAmericas1
    		$95.00 each1

    Description:

    The LM3502 is a white LED driver for lighting applications. For dual display or large single white LED string backlighting applications, the LM3502 provides a complete solution. The LM3502 contains two internal white LED current bypass FET (Field Effect Transistor) switches that are ideal for controlling dual display applications. The white LED current can be adjusted with a PWM signal directly from a microcontroller without the need of an RC filter network.

    With no external compensation, cycle-by-cycle current limit, over-voltage protection, and under-voltage protection, the LM3502 offers superior performance over other application specific standard product step-up white LED drivers. step-up white LED drivers.

    The LM3502/03 evaluation board is a working demonstration of a step up DC-DC converter. The LM3502/03 can drive up to 10 white LEDs. For evaluation purposes, the evaluation board is assembled in a micro SMD package for the 25V version (LM3503ITL) and the 44V version (LM3502ITL). The LM3502/03 are also available in a 16-LLP package (see ordering information). For further information on boost converter topology, device electrical characteristics, and component selection, please refer to the the LM3502 and LM3503 datasheets.

    Features:

    • Drives up to 4, 6, 8, or 10 White LEDs for Dual Display Backlighting
    • >80% Peak Efficiency
    • Output Voltage Protection Options: 16V, 25V, 35V, and 44V
    • Input Under-Voltage Protection
    • Internal Soft Start Eliminates Inrush Current
    • 1 MHz Constant-Switching Frequency
    • Wide Input Voltage: 2.5V to 5.5V
    • Small External Components
    • Low Profile Packages: <1 mm Height
          ---10 Bump MicroSMD
          ---16 Pin LLP

    Applications:

    • Dual-Display Backlighting in Portable devices
    • Cellular Phones and PDAs



    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
    LM3502ITL-16/NOPB

    		4.215
    		MICRO SMD101260DetailDownloadN/A
    		XYTT
    I SANB
    LM3502ITL-25/NOPB

    		4.215
    		MICRO SMD101260DetailDownloadN/A
    		XYTT
    I SAPB
    LM3502ITL-35/NOPB

    		4.215
    		MICRO SMD101260DetailDownloadN/A
    		XYTT
    I SARB
    LM3502ITL-44/NOPB

    		4.215
    		MICRO SMD101260DetailDownloadN/A
    		XYTT
    I SDLB
    LM3502ITLX-16/NOPB

    		4.215
    		MICRO SMD101260DetailDownloadN/A
    		XYTT
    I SANB
    LM3502ITLX-25/NOPB

    		4.215
    		MICRO SMD101260DetailDownloadN/A
    		XYTT
    I SAPB
    LM3502ITLX-35/NOPB

    		4.215
    		MICRO SMD101260DetailDownloadN/A
    		XYTT
    I SARB
    LM3502ITLX-44/NOPB

    		4.215
    		MICRO SMD101260DetailDownloadN/A
    		XYTT
    I SDLB
    LM3502SQ-16/NOPB

    LM3502SQ-16
    		39.462
    39.599
    		LLP161
    1    		260
    260    		DetailDownloadN/A
    		NS
    UZXYTT
    L00048B
    LM3502SQ-25/NOPB

    LM3502SQ-25
    		39.461
    39.599
    		LLP161
    1    		260
    260    		DetailDownloadN/A
    		NS
    UZXYTT
    L00049B
    LM3502SQ-35/NOPB

    LM3502SQ-35
    		39.462
    39.599
    		LLP161
    1    		260
    260    		DetailDownloadN/A
    		NS
    UZXYTT
    L00044B
    LM3502SQ-44/NOPB

    LM3502SQ-44
    		39.462
    39.599
    		LLP161
    1    		260
    260    		DetailDownloadN/A
    		NS
    UZXYTT
    L00050B
    LM3502SQX-16/NOPB

    LM3502SQX-16
    		39.461
    39.599
    		LLP161
    1    		260
    260    		DetailDownloadN/A
    		NS
    UZXYTT
    L00048B
    LM3502SQX-25/NOPB

    LM3502SQX-25
    		39.461
    39.599
    		LLP161
    1    		260
    260    		DetailDownloadN/A
    		NS
    UZXYTT
    L00049B
    LM3502SQX-35/NOPB

    LM3502SQX-35
    		39.461
    39.599
    		LLP161
    1    		260
    260    		DetailDownloadN/A
    		NS
    UZXYTT
    L00044B
    LM3502SQX-44/NOPB

    LM3502SQX-44
    		39.461
    39.599
    		LLP161
    1    		260
    260    		DetailDownloadN/A
    		NS
    UZXYTT
    L00050B

    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 LM3502.

    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 LM3502 is located at RoHS Status.

    CAD Symbols and Models
    Download LM3502 CAD Symbols
    		 Models
    N/A


    Reliability Metrics
    Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
    LM3502ITL-16ABCD15004268000639400011814314958
    LM3502ITL-25ABCD15004268000639400011814314958
    LM3502ITL-35ABCD15004268000639400011814314958
    LM3502ITL-44ABCD15004268000639400011814314958
    LM3502ITLX-16ABCD15004268000639400011814314958
    LM3502ITLX-25ABCD15004268000639400011814314958
    LM3502ITLX-35ABCD15004268000639400011814314958
    LM3502ITLX-44ABCD15004268000639400011814314958
    LM3502SQ-16ABCD15004268000639400011814314958
    LM3502SQ-25ABCD15004268000639400011814314958
    LM3502SQ-35ABCD15004268000639400011814314958
    LM3502SQ-44ABCD15004268000639400011814314958
    LM3502SQX-16ABCD15004268000639400011814314958
    LM3502SQX-25ABCD15004268000639400011814314958
    LM3502SQX-35ABCD15004268000639400011814314958
    LM3502SQX-44ABCD15004268000639400011814314958

    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 LM3502.

    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 LM3502 is located at RoHS Status.

    [Information as of 7-Feb-2012]
    Copyright © 2011 National Semiconductor Corporation