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Device marking conventions
  • Standard first line manufacturing information
  • Small component first line manufacturing information
  • Typical device descriptions (second line)
  • Optional third and fourth line information
  • Very small component marking
  • Additional marking
  • Device marking conventions

    Nationals device marking examples

        National Semiconductor marks devices sold in order to provide device identification and manufacturing traceability information. The method of presenting the information marked on the device is dependent on the size of the device package and the area available for marking as well as the nature and specifications of the device.

        The topics below discuss general marking conventions to help understand device markings similar to those in the examples to the right.

    Standard first line manufacturing information

        The first line of device marking provides manufacturing information as shown in the schematic below.

        Click on the graphic to see how the information is encoded.

    Standard first line manufacturing information Wafer fab plant code Wafer fab plant code Assembly plant code Assembly plant code Year of manufacture code Year of manufacture code Week of manufacture code Week of manufacture code Die run code Die run code

    Small component first line manufacturing information

        On smaller packages, such as SOICs, 8-lead MDIPs, and 20-lead PLCCs, the information is encoded somewhat differently to accomodate the smaller area available as shown in the schmatic below.

        Click on the graphic to see how the information is encoded.

    Small components first line manufacturing information Assembly plant code Assembly plant code Year of manufacture code Year of manufacture code Week of manufacture code Week of manufacture code Die run code Die run code
    CodeFab Location
    ASanta Clara, CA
    BSouth Portland, ME
    CSouth Portland, ME
    EArlington, TX
    FSanta Clara, CA
    HGreenock, UK
    JGreenock, UK
    RSanta Clara, CA
    TSouth Portland, ME
    VSouth Portland, ME
    XArlington, TX
    ZSalt Lake City, UT

    Wafer fab plant codes

        The right table list single letter codes for National Semiconducor's wafer fabrication plants.

        Letters that don't appear on this list indicate wafer fabrication at one of National Semiconductor's approved sub-contractors.

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    CodeAssembly Location
    FSanta Clara, CA
    MMalacca, Malaysia
    SSingapore
    BThailand (Sub-con)
    EKorea (Sub-con)
    HPhilippines (Sub-con)
    IIndonesia (Sub-con)
    JJapan (Sub-con)
    TTaiwan (Sub-con)
    WSingapore (Sub-con)
    XUSA (Sub-con)
    YMalaysia (Sub-con)

    Assembly plant codes

        The following table list single letter codes for National Semiconducor's device assembly plants.

        Letters that don't appear on this list indicate device assembly at another of National Semiconductor's approved sub-contractors.

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    Date of manufacture codes

        Marks indicating the date of manufacture occurs in four, three, or two digit versions. The date code marked represents a six week period in which the device was assembled. The allocation of digits between year and week information in each scheme is summarized below:

    Version Year Digits Week Range Digits
    Four-digit (YYWW) 2 2
    Three-digit (YWW) 1 2
    Two-digit (YW) 1 1

    Year:    The year "code" is very direct and is either the last one or two digits of the calendar year of manufacture. For example, for a device manufactured in 1998, the two-digit "code" is 98, while the one-digit "code" is simply 8.

    Week:    The week code is based on the starting calendar week of the six-week period during which the device was assembled. The table below summarizes the six-week date code schedule for both two- and one-digit codes.

    Six-week period Two-digit code One-digit code
    From week Thru week
    52 05 52 9
    06 11 06 1
    12 17 12 2
    18 23 18 3
    24 29 24 4
    30 35 30 5
    36 41 36 6
    42 47 42 7
    48 51 48 8

        Some examples are shown below:

    Date of Manufacture 4-digit Code 3-digit Code 2-digit Code
    Calendar week 48, 1997 9748 748 78
    Calendar week 6, 1998 9806 806 81
    Calendar week 14, 1998 9812 812 82
    Calendar week 32, 2001 0130 130 15

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    Die run codes

        The die run code is a two letter alpha code, ranging from AB through ZZ for each device, that is automatically assigned to each lot by an internal manufacturing system. When the date code is combined with the die run code, a unique identifier is created. In case of any problems with a device, this identification facilitates backward traceability to manufacturing processes where containment and corrective actions can be defined. These actions, in turn, minimize, and eventually eliminate, any negative impact on customers.

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    Typical device descriptions (second line)

        The second line of marking describes the specific circuit in the package. The schematics below show information shown for typical parts.

        Click on the graphic to see how the information is encoded.

    Typical device descriptions (second line) Device family code Device family code Device family code Device family code Electrical grade code Electrical grade code Temterature range code Temterature range code Package code Package code
    Code Product Family
    ADC Data Conversion
    CGS Clock Generation Support
    COP Control Oriented Processor
    DAC Data Conversion
    DP Local Area Network Products
    DS Interface Products
    LM Linear
    LMX Frequency Synthesizers / PLL
    LP Voltage Regulators
    PC PC Related Products

    Device families, product lines and device type

        Basic device identification is usually provided in the second line of device marking. As indicated, the general form of the identification is a product line indicator along with a numeric description of the specific device.

        The table lists a sampling of device family codes.

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    Electrical grade information

        When present, additional markings between the device identification characters and the package code represent device variations that can be thought of as "grade levels" of the product. These might represent:

  • Improved precision
  • An improved die revision
  • Wider or more narrow specification range
  • Accuracy vs temperature levels
  •     The exact nature of the variations are defined in produt datasheets.

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    Temperature range codes

        The temperature range over which a device's operation is specified may vary over different versions of the basic device. In these cases, a temperature range code indicates the specified range. While the list below lists the most common ranges specified, customers are urged to confirm this data on the datasheets.

  • 0°C to +70°C (Code C)
  • -40°C to +85°C (Code I)
  • -55°C to +125°C (No code)

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    Code Package
    HTO-5 / TO-46
    JCERDIP
    MSOP / SOIC
    MXSOP Tape & Reel
    NMolded DIP
    STO-263
    TTO-220
    UPin Grid Array
    VPlastic Chip Carrier (PCC)
    VFQuad Flat Pak (PQFP)

    Packaging codes

        To meet customer needs, National Semiconductor offers its products in a wide variety of packaging options. The package options available for each device type can be viewed in the datasheets.

        A small sample of packaging codes found within the device description marking is given in the table.

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    Optional third and fourth line information

        Depending on the device, package size, and customer, additional information might appear in a third or fourth line of marking information. Information that might appear on these lines include:

    • Continuation of device identification (if too long for the second line)
    • "Stampoff" number as required by specific customer request and specification
    • Notice(s) related to copyright (©) or trademarks (®)

    Very small component marking

        Certain very small packages, such as SOT-23, SOT-223, SC70, and SC90, are too small to contain all the information discussed above. Device identification marking is assigned differently and can be found in the datasheets.

        Other date code information, which would be typically found in the "first line" marking, is identified on the container labels.

    Additional markings

        With the wide range of product produced by National Semiconductor, additional marking is sometimes needed to indicate a different level of performance or to identify specific functionality. For example, some marks that might occur after the package code or die run code might include the following:

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