The NAND Gate

The NAND gate and NOR gate are called Universal gates because they can perform all the three basic functions of AND, OR and NOT gates.

The NAND Gate

The NAND gate is a AND gate followed by NOT gate. Thus, we can say, it is a NOT-AND operation. It may have two or more inputs but only one output. The logical symbols and truth table of a NAND gate are,

• In NAND gate output is exact inverse of the AND gate for all possible input combinations.
• The OR gate with inverted inputs is called bubbled OR gate or negative OR gate. The NAND gate is also called active low OR gate.
• The switching circuit diagram for a NAND gate is,