## What is AND Gate?

The AND gate will have two or more fan-in or inputs but only one output. A logical AND gate function effectively finds the minimum between two binary digits.

### AND Gate Symbol

The logic symbol two-input AND gate is:

The output of the two or more fan-in or input is said to be 'true' or '1' when all the connected fa-in or inputs is 'true' or '1'. Otherwise, the output becomes zero if any fan-in or input is '0'.

## AND Gate Truth Table

The AND gate truth table is for the two fan-in or inputs, A and B. It has only one output as Y. The output is logic '0' if any inputs A and B are LOW (logic '0'). However, the output is 1 only when all the inputs are 1. The AND gate truth table is as follows:

The logical expression from the above AND gate truth table is Y= AB.

## Properties of AND Gate

The AND gate follows commutative property. That is, if we have two inputs, A and B, then AB = BA. Let us suppose the input A is '1' and B is '0', so the output Y is '0' as per the given AND gate truth table. The same output we get in the commutative property as:

AB = 1.0 = 0

BA = 0.1 = 0

The AND gate also follows associative property. If we have three inputs, A, B and C, then (AB)C= A(BC). Let us suppose the input A is '1', B is '0', and C is '0', so the output Y is '0' as per the AND gate truth table. The same output we get in the commutative property as:

(AB)C =(1.0).0 = 0.0 = 0

A(BC) =1.(0.0) = 1.0 = 0

For AND operations, we have enabled and disabled inputs that are as follows:

If control = 0; the truth table will be:

No change in the output. Hence logic '0' is considered as disabled input for AND gate.

If control = 1; the truth table will be:

Due to change in the input-output also changes; therefore, logic '1' enables input for AND gate.

## Circuit Diagram of AND Gate

Based on the above AND gate truth table, the switching circuit diagram of AND gate is shown below. We have two inputs or switches, A and B, connected serially, and one blub is also connected serially with two inputs the circuit diagram of AND gate is as follows:

The bulb will only glow when switches A and B are closed or at logic '1'. If any switches A and B are open or logic '0', then the bulb will not glow.

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