What is XOR Gate

In this article, we will discuss the XOR gate, a logic gate in digital electronics used to perform exclusive OR operations. Here, we will cover the definition of the XOR gate, its logic symbol, truth table, and the Boolean expression.

XOR Gate Definition

The XOR gate is a type of derived logic gate used in digital electronic circuits to perform exclusive OR operation. It is a two-input and one-output logic gate. XOR gate is also called Exclusive OR Gate, or Ex-OR Gate, or X-OR Gate.

The XOR gate produces a HIGH (Logic 1) output only when its two inputs are in different logic states, i.e. the output of the XOR gate will be HIGH, when its two inputs are 0 and 1 or 1 and 0. When the two inputs of the XOR gate are the same, it produces a LOW (Logic 0) output.

The XOR logic gate is also known as an anti-coincidence gate or inequity detector because it gives output 1 only when its inputs are not equal or coincide.

The output of the XOR gate is obtained by performing the modulo sum of its two inputs.

It is called Exclusive OR gate because it gives in output equal to Logic 1, only when exclusively one of its inputs is a Logic 1.

It is important to note about the XOR gate that three or more input XOR gates do not exist. When we require an XOR gate with inputs of more than two, then multiple two-input XOR gates are connected together to obtain the desired XOR gate.

XOR Gate Symbol

The logic symbol of the two-input XOR gate is shown in the following figure.

Here, A and B are inputs and Y is the output of the XOR gate.

XOR Gate Truth Table

The truth table of the XOR gate is given below:

Inputs		Output
A	B	Y
0	0	0
0	1	1
1	0	1
1	1	0

From the truth table of the XOR gate, it is clear that the output of the XOR gate is logic 1, only when its two inputs are different, and for the same inputs, it gives a logic 0 output.

XOR Gate Boolean Expression

The Boolean expression or logical function of the XOR gate is given below.

`\Y=A⊕B=A\overline{B}+\overline{A}B`

The output of the XOR gate is obtained by performing the modulo sum of its two inputs.

XOR Gate Switching Circuit

The following figure depicts the switching circuit of the XOR gate.

It has two switches A and B, a battery, and a lamp.

From the circuit diagram, it can be seen that when the two switches are at different logic levels, i.e. A = 0 and B = 1 or A = 1 and B = 0, then the circuit completes and the lamp is turned on.

When the two switches are at the same logic level, i.e. A = B = 1 or A = B = 0, the circuit remains open and the lamp remains turned off.

This is how the above switching circuit implements the XOR logical operation.

XOR Gate IC

The IC 7486 is a commonly available quad 2-input XOR gate IC used in various digital electronic systems. It contains four XOR gates in a single IC chip.

The following figure shows the pin diagram of the 7486 XOR Gate IC.

Applications of XOR Gate

The XOR gate is commonly used to implement various digital electronic circuits and systems. Some common digital circuits are listed here that use an XOR gate as their component.

• Half-adder and full-adder circuits
• Sequence detector and corrector circuit
• Binary subtractors
• Pseudo-random number generator

Hence, in this article, we have discussed all the important aspects of the XOR gate (Exclusive OR gate).

Other Useful Resources

You can get more knowledge about XOR gate from the following resources.

• Logic XOR Gate