# NOT AND OR gate using NAND gate – circuit diagram

Earlier we discussed the basic logic gates with truth table, circuit diagram and Boolean expression. The three basic logic gates in Computers are OR gate, AND gate and NOT gate. The universal logic gates like NAND gate and NOR gate are also introduced to you. All logical gates can be designed by using universal logic gates. In other two articles, we learned how to implement XOR gate and XNOR gate using NAND gates.

In this article, we are going to realize OR gate, AND gate and NOT gate i.e. basic logic gates using NAND gate only. Here you will get the circuit diagrams and Truth tables for basic logic gates using NAND gates only.

1. Realize OR gate using NAND gate only
2. Implement AND gate using NAND gate only
3. Realize NOT gate using NAND gate only

## Circuit diagram of OR gate using NAND gates only

The diagram at below is the circuit diagram of two input OR gate using NAND gate only.

If A and B be the inputs of an OR gate then the Boolean expression is, Y = (A + B). To design a two-input OR gate using NAND gate only, three NAND gates are required.

One can verify this circuit practically. After constructing this circuit using NAND gates on a breadboard, realize the truth table. You will find the same truth table as that of an OR gate.

## Circuit diagram of AND gate using NAND gates only

Here is the circuit diagram for the realization of AND gate using NAND gate only.

If A and B are the inputs of a two-input AND gate then the Boolean expression is, Y = A.B. To design the AND gate using only NAND gate, we need two NAND gates. One can verify the truth table of this circuit also.

## Circuit diagram of NOT gate using NAND gate only

Here is the circuit diagram of NOT gate using NAND gate.