What is the meaning of the letters before and after the Mfr. Part number?

Discussion in 'Electronics Resources' started by zachaqsw, Oct 4, 2012.

  1. zachaqsw

    Thread Starter New Member

    Oct 4, 2012
    Ive been trying to buy some electronic components for 3 days now to start learning hands on about electronics because id like to be an electronic technician of some kind in the future. Anyways, Ive looked on here and the web but I'm still confused. Lets say I want to buy like a non-surface mount 555 timer so I go to a website like mouser and I type in "555 timer" and it brings up a lot of results like abcdefg555hijklmnop from what I understand the letters before 555 is the company that makes that chip and the letters after 555 is the model number of that chip from that company? so if that's true, out of the 2 made up chips A555B for $0.15 and C555D for $0.30 I should get the cheaper one to save money? Basically what I mean is why is there so many choices for one specific component and is it bad to get the cheapest one? Also, sry for the newb questions and I appreciate the help.
  2. KJ6EAD

    Senior Member

    Apr 30, 2011
    The prefix letters/numbers will often be specific to a manufacturer, but not always. They frequently indicate a grouping or family of products with similar features or capabilities.

    The suffix letters/numbers often indicate differences in package type or variants of a product such as military, aviation, medical or commercial specification.

    Download several data sheets from different manufacturers of a product that interests you and look for ordering information and notes that describe differences and how they're specified in the part number. This is the only way to really understand them since there is only limited standardization in the industry.

    By the way, the question is perfectly reasonable and might be stated as "is there a standard system to understand here or do I have to embrace a degree of chaos?"
    Last edited: Jul 13, 2018
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  3. MrChips


    Oct 2, 2009
    Everything that KJ6EAD says + don't go by price alone. The price is dictated by the phase of the moon and other unknowns.

    The prefix is often the manufacturer's code, but not always.
    Pay attention to the suffix. They make a difference between getting the right part and the wrong part.

    Yesterday I thought I ordered ten 15-pin VGA connectors. What I received were 15 pins on two rows, not three. Arrgh!:mad:
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  4. bertus


    Apr 5, 2008
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