What is NOT Gate?

What is NOT Gate?

In digital circuits, the NOT gate is a basic logic gate having only a single input and a single output. The output of the NOT gate is logic 0 when its input is logic 1 and the output is logic 1 when its input is logic 0. Thus, the NOT gate is used to perform the inversion operation in digital circuits. It complements the input and produces a corresponding output. Being a basic logic gate, the NOT gate is used in a variety of digital circuits to design and implement their basic logic circuits....

Symbol of NOT Gate

The logic circuit diagram of the NOT gate is shown in the following figure. It has only one input line denoted by the letter A and one output line denoted by the letter Y, where Y is the complement of the input signal applied to it. At the output line, the bubble denotes the complement operation and it is called the inversion bubble....

Truth Table of NOT Gate

The truth table for the NOT gate is as follows. It shows the relationship between input applied and output generated and the working of the NOT gate for all the possible inputs. In a NOT gate, the output (NOT A) is the opposite of the input (A). So, when the input is 0, the output is 1, and when the input is 1, the output is 0....

Use of Active-low Input Bubble

In digital logic the Active-low Input Bubble is represented by a small circle at the input of a gate symbol which indicates that the logic level is inverted. In the case of a NOT gate, which performs inversion, the active-low input bubble indicates that the gates operation is inverted. So, when the input signal has the active-low bubble, it means that the gate will produce an output that is the inverse of the input signal....

Equivalent Gates

Now we will see how we can form not gate using universal gates(NAND and NOR gate)....

NOT Gate Implementation using Transistors

We can implement the NOT gate logic using a bipolar junction transistor. The circuit diagram of a NOT gate using BJT transistor is shown in the following figure....

Applications of NOT Gate

Signal Inversion: The most common use is to invert a digital signal. If you have a logic high signal (1), the NOT gate will produce a logic low output (0), and vice versa....

Advantages and Disadvantages of NOT Gate

There are some list of Advantages and Disadvantages of NOT Gate given below :...

Solved Examples on NOT Gate

A person wants to design a robot such that it moves forward when the obstacle is not detected in front and it stops if there is any obstacle....

Conclusion

NOT gates are fundamental building blocks of digital logic circuits. They have a single input and a single output, and their function is to invert the input signal. NOT gates have wide range of application, including signal inversion, in construction of flip-flops and latches, logical operations, automatic lighting systems, and temperature detection devices. NOT gates are easy to integrate, highly important, and cost-efficient. However, they have limited functionality, consume more power and introduce propagation delay....

NOT Gate – FAQs

What are other fundamental gates other than NOT gate?...