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Understanding the Logic Gates Properties: A Guide for Beginners

Logic gates are fundamental building blocks of digital circuits that perform logical operations on binary inputs (0 and 1) to produce a binary output. These gates are the building blocks of digital systems and computers, where information is represented in binary form. There are several types of logic gates, each with its unique function. The basic logic gates include AND, OR, NOT, XOR (exclusive OR), NAND (NOT-AND), and NOR (NOT-OR). 

                    

Here's a brief explanation of each logic gate and its properties: 


1.) AND Gate: 

  • Operation: Output is high (1) only if all inputs are high (1). 

  • Symbol


AND logic gate in digital electronics
Fig. AND logic gate in digital electronics

  • Truth Table: 

A

OUTPUT

1

 0 

 0 

1

 0 

 0 

 1 

 0 

 1 

 1 

 2.) OR Gate: 

  • Operation: Output is high (1) if at least one input is high (1). 

  • Symbol :

OR logic gate in digital electronics
Fig. OR logic gate in digital electronics

  • Truth Table: 

 A    

B

OUTPUT

 

3.) NOT Gate: 

  • Operation: Output is the complement of the input (1 becomes 0, and vice versa). 

  • Symbol :

NOT gate in digital electronics
Fig. NOT gate in digital electronics

  • Truth Table: 

 OUTPUT

 

4.) XOR Gate: 

  • Operation: Output is high (1) if the number of high inputs is odd. 

  • Symbol :

XOR gate  in digital electronics
Fig. XOR gate in digital electronics

  • Truth Table: 

 A 

 B 

 OUTPUT

1

1

1

0

 Properties:

1. If any one input is connected to gnd, xor gate will act as buffer.

2. If any one input is connected to Vcc, xor gate will acts as inverter.

3. Even parity generator and Odd parity detectors.


5.) NAND Gate: 

  • Operation: Output is low (0) only if all inputs are high (1). 

  • symbol :

NAND gate in digital electronics
Fig. NAND gate in digital electronics

  • Truth Table: 

 A 

 OUTPUT

 

6.) NOR Gate:  

  • Operation: Output is low (0) if at least one input is high (1). 

  • symbol :

NOR gate in digital electronics
Fig. NOR gate in digital electronics

  • Truth Table: 

 B 

OUTPUT

 7.) EX-NOR gate

  • Operation: The Ex-NOR gate outputs a HIGH (1) only when both its inputs, A and B, are equal (either both LOW (0) or both HIGH (1). If one or both inputs are different, the output becomes LOW (0).

  • symbol: