NAND and NOR Gates Circuits

This post is labeled under Digital Design


NAND gate represents the complement of the AND operation. Its name is an abbreviation of NOT and AND. The graphic symbol for the NAND gate consists of an AND gate with a bubble on the output, which denotes the complement of the operation.

The NAND gate is said to be a universal gate because any digital system can be implemented with the NAND gates alone. A complement operation is obtained from the one-input NAND gate that behaves like an inverter or a NOT gate (see Figure 1). AND operations requires two NAND gates. The first produces the NAND operation and the second inverts the output signal of the first. OR is achieved using A NAND gate with NOTs on each input. Using Demorgan’s theorem, the inversions cancel out and OR function is the result.



Another universal gate is the NOR gate. It is considered as the dual of NAND gate. The implementation of the AND, OR, and NOT operations with NOR gates can be achieved as seen on Figure 2. One-input NOR gate makes it as a NOT gate just as we did in NAND gate. The OR operation is obtained by using two NOR gates; one NOR gate that accepts the input and another NOR gates that inverts it. AND operation is obtained by having two NOT inputs.

Experiment 2 simulates the operation of NAND and NOR gates. Refer to the step-by-step procedures to learn the principles behind the circuits.
NAND NOR Gates Experiment 2