working of logic gates

Discussion in 'General Electronics Chat' started by mindgame, Apr 22, 2006.

  1. mindgame

    Thread Starter New Member

    Apr 22, 2006
    i want to have some clear concept about how actually logic gates for example AND gate. i know the truth tables but want to know the basic theory that how to get the truth table

    in AND gate if we have both inputs 1 then how the output is one. and if one is zero how the output is zero.
    kindly help me or send me any website that can answer the questions of how and why.
  2. hgmjr

    Retired Moderator

    Jan 28, 2005
    A great place to start is by reading througth the tutorials on this website. You should find them very helpful in explaining the basic concepts of "AND" gates at the link below.

    AND gates and NAND gates Tutorial.

  3. Dave

    Retired Moderator

    Nov 17, 2003
    Generally speaking logic gates are made from transistors organised to produce the necessary logic function. Further to the link provided by hgjmr, you are advised to look at the CMOS implementation for logic gates since this is the most common type in use in industry today:

    A point to note about CMOS is that it is inverting by nature, therefore an AND gate is created by cascading a NAND gate with an INVERTER.

  4. hgmjr

    Retired Moderator

    Jan 28, 2005
    Good point, Dave.

    CMOS should be included in any in-depth investigation into the topic of logic gate operation.

  5. windoze killa

    AAC Fanatic!

    Feb 23, 2006
    One way you can consider an AND gate is switches in series. You need both of them closed to provide an O/P. In the same vien OR gates would be switches in parallel. Either switch closed and you get an O/P.