This article covers the Difference between combinational and sequential circuit. These circuits are important part of digital electronics.
Combinational Circuit
Combinational circuit is a type of circuit whose output depends upon the input provided. It provides instant output and is independent of time. A combinational circuit doesn’t require feedback for further output.
In combinational circuits, only the present input is required. So the performance of the circuit becomes faster and better when compared to sequential circuit. It has simple circuit and used logic gate as basic building blocks. Combinational circuit can be used in both arithmetic and Boolean circuit.
Combinational Circuit Diagram
The block diagram for combinational circuit is shown in figure below
Sequential Circuit
Sequential circuit are the type of circuit whose output depends on both current and previous input. The output obtained from the previous input is transferred in the form of feedback and the circuit uses it again for generating next output.
Sequential circuits are slow when compared to combinational circuits. The feedback feature makes the circuit complex. They use flip – flop as basic building blocks of circuit.
Sequential circuit diagram
The block diagram for sequential circuit is shown in figure below
Difference Between Combinational and Sequential Circuit
| Combinational Circuit | Sequential Circuit |
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1. | In combinational circuits, output depends only upon present input. | In sequential circuits output depends upon both present and previous input. |
2. | It has Fast speed. | It has Slow speed. |
3. | Combinational circuits can be designed easily. | Sequential circuits are difficult to design when compared to combinational circuit. |
4. | These circuit doesn’t have any feedback between input and output. | These circuits have feedbacks between inputs and output. |
5. | Elementary building block : logic gate | Elementary building block : flip flop |
6. | Used in arithmetic as well as Boolean operation. | Mainly used for storing data. |
7. | They nether have clock nor they require triggering. | They are clock dependent and needs triggering. |
8. | Combinational circuits don’t have memory element. | Sequential circuit have memory element. |
9. | It is easy to handle and use. | It is difficult to handle and use. |
10. | Example : 1. Encoder 2. Decoder 3. Multiplexer 4. demultiplexer | Example : 1. Flip flop 2. counter. |
Author
Half adder and full adder is a part of combinational circuits. Combinational circuits are those whose output characteristics depends on their input levels at a particular time.
Excellent explanation 👍👍
Thanks a lot. Keep Supporting.