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IC number prefixes UCC UC TL SG meaning?

Other Parts Discussed in Thread: SG2524, UC28025, UCC28950, UCC2895

Dear All,

I have two questions about IC numbers:

1) what is the meaning of prefixes, ie UCC, UC, SG, TL? ( for example SG2524 or UCC2813 )

2) what is the meaning of digits after prefixes? some ICs have for digit after the prefix and some others have five. ( eg UC28025 or UCC28950 )

Best Regards, Ras

  • Hello Ras

    Some of these prefixes have been acquired as Texas Instruments purchased other Semiconductor companies. UC and UCC certainly came from the Unitrode acquisition. Others would have come from the acquisition of National Semiconductor.

    The digits after the prefixes have various meanings and sometimes none. Because of the way the portfolio was acquired / developed over the years there is not any real consistency here and I hesitate to go further than that.

    My advice is to treat them as unique identifiers and not to worry about decoding them. The TI website has a product selection tool which will do a good job of finding the part(s) which suit your application.

  • Hi Colin Gillmor,
    thank you for the reply.
    i have two questions:
    1) how do i know the year of product development to select new products?
    2) when i use the selection tool, ( after filtering/focusing in my search, ) i reach a lot of similar choices for a special application. how can i have a good selection between them? for example in pwm controllers there are several products for flyback.

    Regards, Ras

  • Hello Ras

    1/ The Power Management parts are typically listed according to the type of application they are designed for. The Offline and Isolated DC/DC controllers and converters section for example lists Power Factor Correction controllers. PWM controllers and resonant controllers and Flyback controllers among others. TI doesn't include information about the year of product development but each part does include a status flag, if the part is listed as being ACTIVE then it is in full production irrespective of when it was designed and you may be confident in its continued availability.

    2/ The selection tool will get you an initial list for you to select between. Unfortunately there is no good way to further refine this search other than by manually comparing the part's specifications against your requirements.

  • Hello Ras,
    Here is some more insight from a former Unitrode employee.

    UC bipolar Unitrode device.
    UCC bicmos Unitrode device
    UCD = Unitrode branded digital control
    SG Silicon General prefix used by many suppliers of PWM’s

    TL Texas Instruments Linear
    TLC TI Linear BiCmos


    The other digits are all part of a general part numbering scheme for a device family.
    Example, when a 4 digit device family needs expanding a 5th number is many times added   UCC2895     to UCC28950 newer phase shift pwm.

    Some devices are many decades old so the numbers after the prefix has imbedding meanings.
    UC1xxxx  UCC1xxxx  indicates a military temp
    UC2  UCC2 indicates industrial temp,  SG2 also indicates industrial temp I believe.
    UC3 UCC3 indicates commercial temp

    No newUC bipolar devices are being made.
    UCC new devices are all UCC2 industrial temp by default, mil specs have suffixes added.

    There are more variations I surely have missed, but I hope this helps your understanding.

  • Dear Ed Walker,
    i have two another questions:
    1) can i have this information about LM series?
    2) you said TL stands for linear. what does it mean when we speak in pwm switching controllers?

    Best Regards, Ras
  • Hello Ras,
    I cannot answer the LM series because it was National Semi, which I was not part of.

    Regarding TL for PWM's, TI had some time ago digital logic groups and linear groups.
    TL was used to differentiate a linear device versus a digital device.

    The prefix's now don't have the meaning they used to.
    As Colin has mentioned, you should use selection guides and TI.COM to find devices that meet your need.