XNOR Gate

An XNOR gate (sometimes referred to by its extended name, Exclusive NOR gate) is a digital logic gate with two or more inputs and one output that performs logical equality. The output of an XNOR gate is true when all of its inputs are true or when all of its inputs are false. If some of its inputs are true and others are false, then the output of the XNOR gate is false.

The truth table for an XNOR gate with two inputs appears to the right.

Symbols

Each of the symbols below can be used to represent an XNOR gate. There are multiple international standards defined, and one may preferred over the other in your region of the world.

ASNI / IEEE	IEC

Live Example

Try the following interactive example to see for yourself how an XNOR gate behaves.

Further Reading

To learn more, check out the following external resources:

• XNOR gate on Wikipedia

• Multiple-input gates on All About Circuits

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