National Semiconductor | High-performance Analog

 

 LMX2485E   

Delta-Sigma Low Power Dual PLL for RF Personal Communications
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Features

Quadruple Modulus Prescalers for Lower Divide Ratios

  • RF PLL: 8/9/12/13 or 16/17/20/21
  • IF PLL: 8/9 or 16/17
  • Advanced Delta Sigma Fractional Compensation

  • 12 bit or 22 bit selectable fractional modulus
  • Up to 4th order programmable delta-sigma modulator
  • Features for Improved Lock Times and Programming

  • Fastlock / Cycle slip reduction
  • Integrated time-out counter
  • Single word write to change frequencies with Fastlock
  • Wide Operating Range

  • LMX2485 RF PLL: 500 MHz to 3.0 GHz
  • LMX2485E RF PLL: 50 MHz to 3.0 GHz
  • Useful Features

  • Digital lock detect output
  • Hardware and software power-down control
  • On-chip crystal reference frequency doubler.
  • RF phase comparison frequency up to 50 MHz
  • 2.5 to 3.6 volt operation with ICC = 5.0 mA at 3.0 V
  • Description

    The LMX2485 is a low power, high performance delta-sigma fractional-N PLL with an auxiliary integer-N PLL. The device is fabricated using National Semiconductor’s advanced process.

    With delta-sigma architecture, fractional spurs at lower offset frequencies are pushed to higher frequencies outside the loop bandwidth. The ability to push close in spur and phase noise energy to higher frequencies is a direct function of the modulator order. Unlike analog compensation, the digital feedback technique used in the LMX2485 is highly resistant to changes in temperature and variations in wafer processing. The LMX2485 delta-sigma modulator is programmable up to fourth order, which allows the designer to select the optimum modulator order to fit the phase noise, spur, and lock time requirements of the system.

    Serial data for programming the LMX2485 is transferred via a three line high speed (20 MHz) MICROWIRE interface. The LMX2485 offers fine frequency resolution, low spurs, fast programming speed, and a single word write to change the frequency. This makes it ideal for direct digital modulation applications, where the N counter is directly modulated with information. The LMX2485 is available in a 24 lead 4.0 X 4.0 X 0.8 mm LLP package.


    Applications

  • Cellular phones and base stations

  • CDMA, WCDMA, GSM/GPRS, TDMA, EDGE, PDC
  • Direct digital modulation applications
  • Satellite and cable TV tuners
  • WLAN Standards
  • LMX2485E WEBENCH®
    Design/Analyze/Build It
    RF-Side PLL Design Options
    Min Output Freq MHz >= 50 help
    Max Output Freq MHz <= 3000 help
    Channel Spacing KHz > 0 help
    AUX-Side PLL Design Options
    Min Output Freq MHz >= 75 help
    Max Output Freq MHz <= 800 help
    Channel Spacing KHz > 0 help
    Global Design Options
    Crystal Frequency MHz > 0 help
    Max Supply V > 0 help
    What is WEBENCH®?

    Also Recommended
    LMX24864.5 GHz Maximum Operating Frequency.
    LMX24876.0 GHz Maximum Operating Frequency.
    LMX2487E7.5 GHz Maximum Operating Frequency.

    Parameters / ValuesLMX2485E LMX2486 LMX2487 LMX2487E
    Max PLL Freq3000 MHz 4500 MHz 6000 MHz 7500 MHz
    Min PLL Freq50 MHz 1000 MHz 1000 MHz 3000 MHz
    Max Aux PLL Freq800 MHz 3000 MHz 3000 MHz 3000 MHz
    Min Aux PLL Freq75 MHz 250 MHz 250 MHz 250 MHz
    Normalized PLL Phase Noise-210 dBc/Hz -210 dBc/Hz -210 dBc/Hz -210 dBc/Hz
    Supply Current5 mA 8.5 mA 8.5 mA 8.5 mA
    Number of PLLs2 2 2 2
    PLL TypeDelta-Sigma Fractional-N RF/IF Dual Delta-Sigma Fractional-N RF/IF Dual Delta-Sigma Fractional-N RF/IF Dual Delta-Sigma Fractional-N RF/IF Dual
    Min Supply Voltage2.5 Volt 2.5 Volt 2.5 Volt 2.5 Volt
    Max Supply Voltage3.6 Volt 3.6 Volt 3.6 Volt 3.6 Volt
    FastlockYes Yes Yes Yes
    Temperature Min-40 deg C -40 deg C -40 deg C -40 deg C
    Temperature Max85 deg C 85 deg C 85 deg C 85 deg C
    Power ConsumptionUndefined Watt Undefined Watt Undefined Watt Undefined Watt
    PowerWise Rating 6Undefined mW x ps /ch Undefined mW x ps /ch Undefined mW x ps /ch Undefined mW x ps /ch
    PowerWiseUndefined Undefined Undefined Undefined

    Datasheets
    TitleSizeDateOther
    Language
    LMX2485E Delta-Sigma Low Power Dual PLL for RF Personal Communications763
    Kbytes
    27-Feb-08日本語  

    Part Number(s)
    (NSID)
    Top ViewAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LMX2485ESQ/NOPB


    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide3417
    AVNET-EMWorldwide1000
    DIGI-KEYWorldwide1758
    FARNELLEurope and Asia667
    MOUSERWorldwide999
    NEWARKAmericas667
    TAYLORAmericas3417
    $2.60 each at 1K+ pcsreel
    of
    1000
    LMX2485ESQX/NOPB


    RoHS Status


    LLP
    Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $2.60 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 LMX2485E.

    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 LMX2485E is located at RoHS Status.

    Part Number(s)
    (NSID)
    DescriptionAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LMX2485E EVAL/NOPB

    Delta-Sigma Low Power Dual PLL for RF Personal CommunicationsFull production
    Lead Free (RoHS)

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    $176.00 each1

    Contents:

    • A Fully Assembled LMX2485E Evaluation Board
    • Code Loader Cable
    • LMX2485E Evaluation Board Instructions

    Resources:

  • LMX2485E Evaluation Board Instructions



  • 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
    LMX2485ESQ/NOPB

    39.849
    LLP243260DetailN/AN/A
    NS
    UZXYTT
    2485EDD
    LMX2485ESQX/NOPB

    39.849
    LLP243260DetailN/AN/A
    NS
    UZXYTT
    2485EDD

    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 LMX2485E.

    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 LMX2485E is located at RoHS Status.

    Design Tools
    TitleSizeDate
    LMX2485E Evaluation Board Instructions  
    Design and Simulation Software & CodeLoader Programming 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)
    LMX2485ESQBICMOS8215238132018125002514301823
    LMX2485ESQXBICMOS8215238132018125002514301823

    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 LMX2485E.

    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 LMX2485E is located at RoHS Status.

    [Information as of 9-Feb-2012]