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Naming of semiconductor devices

  1. Nov 19, 2013 #1
    In my college, we used this transistor named SL100 and another one named CL100 for various experiments. But why are they named that way? I browsed the net for an answer for almost an hour but couldn't find a proper answer to this? What does S and L mean? what does 100 mean?
    From the Datasheets, I found that SK100 and CK100 are PNP transistors and SL100 and CL100 are NPN transistors, so I inferred that 'L' denotes that it is an NPN transistor and K for PNP transistor... But I am not sure. Some sources say S stands for "slew" and L for low frequency...

    Then I landed up in this wiki page: http://en.wikipedia.org/wiki/Pro_Electron

    But this says 'S' is for Solitary digital integrated circuits. I have no clue what is that supposed to mean! And that wiki link is the one with the "MOST DETAILS" that i could find. Someone please help me with this... :cry::frown::confused:
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  3. Nov 19, 2013 #2


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  4. Nov 19, 2013 #3


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    AFAIK transitors do not have standardized names, it is up to the manufacturer to call them whatever they want. Sometimes the names actually mean something, but sometimes the names are just internal designations and the numbers/letters are essentially just random (or have something to do which generation of device it etc)

    Note also that is quite common for other manufacturers to use the same names/numbers once the orignal manufacturers patents have run out. This just means that these devices can be used as drop-in replacements for the originals. The most famous example would be the 741 op-amp which has been around for 50 years, it was originally made by Fairchild Semiconductor but now they are sold by lots of companies; the name still does not really mean anything more than that it was part of the 700 series at Fairchild.

    Hence, it is a bit like asking why Porche named their car "911".
  5. Nov 19, 2013 #4


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    Or Porsche.

    Actually, the 911 got its name because Porsche got into a fight with Peugeot about the original name for this car, the 901 (based on Porsche's internal project number for the design). Peugeot claimed priority in three-digit names for cars where the middle digit was '0'. To avoid a prolonged and costly fight, Porsche changed the original name '901' to '911'.

  6. Nov 19, 2013 #5


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    Somebody once said "standards are very important for computer software development. That's why were are so many different ones".

    The same applies to semiconductors: http://www.semicon-data.de/info/namings.html [Broken]

    But note that the US "standard" is hardly worth the name, since it doesn't say much except diodes are numbered 1N... and transistors 2N...
    Last edited by a moderator: May 6, 2017
  7. Nov 19, 2013 #6
    So SL100, CL100, SK100 and CK100 are transistors which do not follow these standard naming conventions which are there, isn't it? So in my Analog electronics Laboratory viva, If they ask me something about components which follow european standard of naming or american standard of naming, I can at least tell something about it. But if they ask "What does S and L stand for in SL100, or something like that? According to my friends and seniors, such questions have been asked by the external examiners, though I feel it is a silly and a stupid thing to ask. So in case they ask such questions related to this, What should I answer?
  8. Nov 20, 2013 #7
    someone Please reply... I promise this will be my last question... my practical exam is nearning and i want to be prepared with an answer for this question...
  9. Nov 20, 2013 #8


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    I found this, but it doesn't cover all those letters you posted. Sure hope it helps.

    "Transistor coding follows two systems namely European coding system and American coding system. In European coding system, two alphabets are used before the part number. The first alphabet represents the semiconductor used and the second alphabet represents its use.

    First Letter
    A- Germanium
    C-Gallium Arsenide
    D-Indium Antimide

    Second Letter
    C-Audio frequency amplifier
    D-Audio frequency power amplifier
    F-Low power radio frequency amplifier
    P-High power radio frequency amplifier

    According to the American system of coding, the code begins with 2N which is followed by the number that indicates the time of design. A higher number indicates recent design.
    Example is the transistor 2N 2222, 2N3055, 2N3904"
  10. Nov 21, 2013 #9


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    there is NO definitive answer
    As someone has already said, the manufacturers will name them what ever they like
    sometimes it will follow a pattern sometimes it wont

    SL100, CL100, SK100 and CK100 ... these could easily be the same transistor made by 4 different manufacturers. or they could just as easily be a mix of transistors and IC's from different manufacturers

  11. Nov 23, 2013 #10
    That sounds like a convincing answer! Thanks Dave! :smile:
  12. Nov 23, 2013 #11
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