1 of 20

Logic gates using universal gates

Submitted By:-Mrs.Mehak Kapoor

Assistant Professor in Computer Science & IT Dept.

2 of 20

Realization of Logic Gate Using Universal gates

In Boolean Algebra, the NAND and NOR gates are called universal gates because any digital circuit can be implemented by using any one of these two i.e. any logic gate can be created using NAND or NOR gates only.

3 of 20

Every logic gate has a representation symbol. The below image shows a graphical representation of all logic gates.

4 of 20

1. Implementation of AND Gate using Universal gates.�

a) Using NAND Gates:The AND gate can be implemented by using two NAND gates in the below figure

5 of 20

b) Using NOR Gates:

Implementation of AND gate using only NOR gates as shown below:

6 of 20

2. Implementation of OR Gate using Universal gates.

a) Using NAND Gates: The OR gate can be implemented using the NAND gate as below

7 of 20

b) Using NOR Gates:Implementation of OR gate using two NOR gates as shown in the picture below:

8 of 20

3. Implementation of NOT Gate using Universal gates.

a) Using NAND Gates:

9 of 20

b) Using NOR Gates:

10 of 20

4. Implementation of XOR Gate using Universal gates.

a) Using NAND Gates

11 of 20

b) Using NOR Gates

12 of 20

5. Implementation of XNOR Gate using Universal gates.

a) Using NAND Gate

13 of 20

b) Using NOR Gate:

14 of 20

6. Implementation of NOR Gate using NAND Gates

15 of 20

7. Implementation of NAND Gate using NOR Gates

16 of 20

Applications of Logic Gates

NAND Gates are used in Burglar alarms and buzzers.
They are basically used in circuits involving computation and processing.
They are also used in push button switches. E.g. Door Bell.
They are used in the functioning of street lights.
AND Gates are used to enable/inhibit the data transfer function.
They are also used in TTL (Transistor Transistor Logic) and CMOS circuitry.

17 of 20

Advantages of Logic Gates

Logical Operations are performed using Boolean Algebra which makes the circuit design more economical and simple.
Logic ‘1’ and Logic ‘0’ can be easily distinguished.

18 of 20

Disadvantages of Logic Gates

Operating Voltage is limited.
Time delay occurs between input and output.

19 of 20

ADVANTAGE OF UNIVERSAL GATES

the main advantage of the universal logic gates is that it can be used to made any kind of logic gate .
by using it - nand and nor are called as universal gates are used to make any gates as or ,and, xnor,not.
logic gates are used in many everyday electronic devices such as tv's, computers and telephones.