An XNOR gate, short for Exclusive NOR gate, is a digital logic gate that performs the logical XNOR operation on two binary inputs to produce a single binary output. The output of an XNOR gate is high (1) when the number of high inputs is even; otherwise, the output is low (0). In other words, the output is high if the inputs are the same as each other.

The logic symbol for an XNOR gate is represented as follows:

   ----       ----
A |    |    B |    |
  | XNOR|      |    |
---|    |    ---|    |
   ----       ----
     Output

In this symbol:

  • A and B represent the input signals.
  • The XNOR symbol in the middle represents the logical XNOR operation.
  • The output is the result of the XNOR operation.

The truth table for a 2-input XNOR gate is as follows:

ABOutput
001
010
100
111

The truth table shows the output for all possible combinations of input values. As per the truth table, the output is 1 when the inputs are the same; otherwise, the output is 0.

XNOR gates are used in various digital applications, including:

  • Comparators to determine equality between two binary values.
  • Odd-parity generators for error detection.
  • Code converters and binary encoders.
  • Building blocks for complex logical operations.
  • Data storage and sequential logic circuits.

By integrating XNOR gates with other logic gates, more intricate digital circuits can be constructed to perform a wide range of tasks in electronic devices and systems.