regarding digital circuits

Discussion in 'General Electronics Chat' started by elisettynarendra, Jul 19, 2010.

  1. elisettynarendra

    Thread Starter Member

    May 17, 2010
    42
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    using TTL which gate is faster either ' and ' or ' or ' ?
    when we are simplifying expression using k-maps when do we require the expression in pos form and sop form ? i mean do they have any advantages over one another in designing circuits ?
     
  2. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,172
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    0 1 output state
    7400 NAND 7 11 ns
    7402 NOR 8 12
    7408 AND 12 17
    Signetics, 1972 does not show an OR in 74XX

    Guess: NAND most common. can be used for most functions.
     
    Last edited: Jul 19, 2010
  3. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
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    Signetics in 1984 has:
    7432 (quad OR) - 12 ns
    74LS32 - 14 ns
    74S32 - 4 ns

    7486 (XOR) - 14 ns
    74LS86 - 10 ns
    74S86 - 7 ns
     
  4. bc108

    New Member

    Jul 18, 2010
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  5. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    In about 1973 I switched from using old 74xx TTL logic ICs to the better TTL 74LSxxx ICs.
    I haven't used old TTL logic since about 1976 when I discovered Cmos logic ICs. Then a little later I used high speed Cmos.
    That was 34 years ago.

    Is your country 34 years behind my country?? Are those old parts still available??
     
  6. elisettynarendra

    Thread Starter Member

    May 17, 2010
    42
    1
    tnx for ur reply . i just posted it for information sake.if possible can u tell
    " when we are simplifying expression using k-maps when do we require the expression in pos form and sop form ? i mean do they have any advantages over one another in designing circuits ? "
    tnx in advance
     
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