Digital Logic Gates
The NAND gate


  1. The NAND gate is a logic gate that has two or more inputs. The name NAND is derived from a contraction of NOT-AND.
  2. The output of the NAND gate is such that the output is a binary 1 if any of the inputs are binary 0.
  3. The output will be binary 0. If and only if all of the inputs are binary 1.
  4. The Standard logic symbol for the NAND gate.

    [nand1.gif]

  5. The equation at the output of the NAND gate is [nand2.gif], expresses the output Y in terms of the input variables A and B. It is read, Y equals NOT A and B.
  6. The NAND function is designated by the dot between the two input variables A and B with a line above A and B (negating factor) .
  7. The NAND function is designated by an expression similar to the product of algebraic variables. It is referred to as a Boolean expression for an NAND gate.
  8. The truth table for an NAND gate.

    [1ttnand1.gif]