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SN54L74J

Other Parts Discussed in Thread: SN54LS74A

Is SN54L74J still available and what is the difference from SN54L74.

  • Hi Marvin,

    I'm not familiar with the SN54L74J or SN54L74, however I am extremely familiar with the TI logic portfolio.

    SN means "Semiconductor Network"

    54 indicates a military rated logic type device

    L usually would indicate the family, but I'm not familiar with any "L" family

    74 indicates the function number, which is a dual D-Type Fip-Flop.

    That's the whole part number for a generic part number (GPN). SN54L74 would be your GPN, if L were a valid logic family.

    Orderable part numbers (OPN) include additional information:

    J would be the military CDIP package. In this case, your OPN would be SN54L74J

    There's a short video that discusses all of this in detail: Anatomy of a logic part number

    As far as I know, we have never had an "L" logic family, but we do have an "LS" logic family that was popular quite some time ago (it's bipolar based logic).

    I would bet that this is just a typo or shorthand -- the SN54LS74A is still available today in the J package: https://www.ti.com/lit/ds/symlink/sn74ls74a.pdf 

  • Is TI PN SNM54L74 the same as TI PN SN54L74? Both are National Stock Number listed as legitimate TI PNs. What does the SNM in the PN stand for? Sorry about starting new threads, did not realize it was that big a deal.

  • Emrys Maier said:
    As far as I know, we have never had an "L" logic family

    That was the "Low-Power TTL" family:

  • Hey Marvin,

    No big deal - just trying to keep everything in one place. I'll delete the other two threads.

    From what Clemens said, there was a TTL logic family called "L," which I assume has been discontinued for a long time since I can't find a single record of it in any of our systems (they go back to the late 1990's).

    Since the 54 already means "military" I'm not sure why there would be an M -- it might be an indicator of a certain rating, but without any official records of the parts, I can't really look into it.

    Are you trying to find a replacement for a particular application?

  • I can not quite read the sheet above, is the TI Low Power device SM54L74 or SN54L74? So the L is for Low Power and 54 is military? Also a J on the end of PN is military? Do we know what the M in the PN stands for as in SNM54L74?

    Thanks

  • Hey Marvin,

    Yes, the L indicates the logic family, which is "Low power TTL" and the "54" indicates military temperature rating (-55 to +125C).

    The J at the end indicates the ceramic CDIP package, which is only available for military parts.

    I haven't been able to find a good definition for the "M" at the start.

    "SNJ" was used for MIL-PR-38535 (QML) devices, while "SNV" was used for MIL-PRF-38535 QML Class V parts, and "SN" was typically used to indicate "Commercial Processing" -- but the document I found with these definitions doesn't include an "SNM" in the list, so I'm still looking.

    I did find the databook that contained this part - which is the 1976 edition of the TTL databook, however it doesn't have any listing of part numbers and I didn't find a reference to an "SNM" logic device anywhere.

    There are a few parts out there that add an "M" to the end of the device to indicate a military temperature rating.