What type of IC is the 4011?

Discussion in 'General Electronics Chat' started by XzQshnR, May 3, 2012.

  1. XzQshnR

    Thread Starter New Member

    May 3, 2012
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    I had my project demonstration and the teacher asked what type it was. I said it was CMOS but he kept on saying it was a TTL. Can some one verify what type of IC it is? The code is CD4011BE.
    Please reply soon!!
     
  2. anotheruser1

    Member

    Dec 6, 2011
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    The manufacturer says cmos
     
  3. MrChips

    Moderator

    Oct 2, 2009
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    You are both correct. It is both CMOS and TTL.

    TTL stands for Transistor-Transistor Logic where gate functions are implemented using transistors. There are other historical types of logic such as resistor-diode, resistor-transistor, diode-transistor logic. One can still create a simple AND function using two diodes and a resistor when in a pinch.

    CMOS is the type of transistors used in the implementation.
    There are bipolar junction transistors (BJT) that are used in the 74LS00 series logic gates.

    CMOS (Complementary Metal-Oxide-Semiconductor) is a process for fabricating a type of field effect transistor (FET) used in CD4000 and MC14000 series gates.

    In general, when we say TTL logic we refer to the BJT implementation in 7400 and 74LS00 family.
    When we say CMOS, we mean the 4000 series or MC14000 series. Hence in that respect, you are correct to call it CMOS and he is only half correct.

    Of course confusion arises with the 74C00, 74HC00 and 74HCT00 series which are also CMOS.
     
    Last edited: May 3, 2012
  4. XzQshnR

    Thread Starter New Member

    May 3, 2012
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    Wow, quick response :)
    Thanks :)
     
  5. SgtWookie

    Expert

    Jul 17, 2007
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    I would not be so generous as MrChips is trying to be.

    The IC in question is a 4000-series CMOS quad NAND gate.
    It does not conform to the 74 series TTL specification, nor would it directly interface with TTL; thus it is not TTL compatible.

    74 series TTL must be operated on a supply with a range from 4.5v to 5.5v, current draw is in the tens to hundreds of milliamperes, input impedance is relatively low, and maximum speeds can range upwards of 40MHz.

    4000 series CMOS can operate on a supply with a range from ~3v to ~18v, current draw is in the microampere range, input impedance is relatively high (>10s of megohms), and maximum speeds are usually limited to ~3MHz.

    They are very different critters.
     
    Last edited: May 3, 2012
  6. crutschow

    Expert

    Mar 14, 2008
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    I agree with SW. TTL historically only refers to the 7400 series logic family with bipolar circuitry (74xx, 74LSxx, 74Sxx). It was call TTL to differentiate it from the DTL (diode transistor logic) common at the time, since it used a multiple emitter transistor at the input to perform the logic function rather then diodes.

    CMOS is never referred to as TTL.

    So I give the instructor a failing grade on that one. I hope he's not that misinformed in other areas of electronics. ;)
     
  7. t06afre

    AAC Fanatic!

    May 11, 2009
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    I also agree with that the answer CMOS is correct and TTL is wrong. The TTL name has as long as I can think back. Been dedicated to logic circuits with bipolar transistors only. If I was a teacher I might have asked a follow up question and asked what kind of logic gate function it had. Just to get "CMOS quad NAND gate" answer.
    If the case is correct described. I am sad to hear that a teacher do such a mistake
     
  8. XzQshnR

    Thread Starter New Member

    May 3, 2012
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    So this means that I was right and he was wrong ? :D
    Awesome, Im gonna go and present the points that you guys made and prove that I was right and I need my deducted marks back
     
  9. t06afre

    AAC Fanatic!

    May 11, 2009
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    Show him this thread also.....;)
     
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