## Logic Gates

In this page you will learn about What is logic gates and its fundamental types with its logic diagram symbol and Truth Table. After reading this page you will able to define Logic gates and its fundamental types.

Logic Gates is an electronic circuit having one or more than one input signals to produce standard output signals. A computer performs out all operations internally by means of combinations of signals passing through standard blocks of built in circuits known as logic gates. It is a building block of digital system. The relationship between input and output is based certain logic. Electronic circuits is made up of the combination of multiple logic gates of different types.

## Fundamental Types of Logic Gates:

• NOT Gate
• AND Gate
• OR Gate
• XOR Gate
• NAND Gate
• NOR Gate
• Exclusive NOR Gate

## NOT Gate

NOT Gate accepts one input signal (0 or 1) and returns the opposite signal as output.

Logic diagram symbol :

Boolean Expression : A = A'

Truth Table :

 Input Outpt A A’ 0 1 1 0

## AND Gates

AND Gates It accepts two input signals, if both input signals are 1 then output is 1 otherwise output is 0.

Logic diagram symbol :

Boolean Expression : C = A·B

Truth Table :

 Inputs Output A B C = A·B 0 0 0 0 1 0 1 0 0 1 1 1

## OR Gates

OR Gates accepts two input signals if both input signals are 0, then output is 0 otherwise output is 1.

Logic diagram symbol :

Boolean Expression : C = A+B

Truth Table :

 Inputs Output A B C = A+b 0 0 0 0 1 1 1 0 1 1 1 1

## XOR Gate

XOR Gate accepts two input signal. If both input signals are same then output is 0 otherwise output is 1.

Logic diagram symbol :

Boolean Expression : C = AB or A'B+AB'

Truth Table :

 Inputs Output A B C= A⊕B 0 0 0 0 1 1 1 0 1 1 1 0

## NAND Gate

NAND Gate accepts two input signal. if both input signals are 1 then output is 0 otherwise output is 1.

Logic diagram symbol :

Boolean Expression : C = (A·B)'

Truth Table :

 Inputs Output A B C=(A·B)' 0 0 1 0 1 1 1 0 1 1 1 0

## NOR Gate

NOR Gate accepts two input signals. If both input signals are 0 then output is 1 otherwise output is 0.

Logic diagram symbol :

Boolean Expression : C = ( A+B )'

Truth Table :

 Inputs Output A B C = (A+B)’ 0 0 1 0 1 0 1 0 0 1 1 0

## Exclusive NOR Gate

Exclusive NOR Gate It accepts two input signals. If both input signals are same then output 1 otherwise output is 0.

Logic diagram symbol :

Boolean Expression : C = A☉B or AB+A'B'

Truth Table :

 Inputs Output A B C =A⊙B 0 0 1 0 1 0 1 0 0 1 1 1

### Conclusion:

In this article, we have thoroughly read about Logic gates and its types with brief description of each fundamental logic gates. Types of fundamental logic gates are:
• NOT Gate
• AND Gate
• OR Gate
• XOR Gate
• NAND Gate
• NOR Gate
• Exclusive NOR Gate
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