The main difference between combinational and sequential circuits is the output of the combinational circuit depends upon the present input only whereas the output of the sequential circuit depends upon the present input as well as past input.

Another big difference between combinational and sequential circuits is, that the combinational circuit is time-independent and it is very fast in operation whereas the sequential circuit is time-dependent and comparatively slower in operation.

In the case of a combinational circuit, there is no feedback path between output and input. On the other hand, in the case of a sequential circuit, there is a feedback path available between output and input. So, the sequential logical circuit works in a loop, it can generate multiple outputs corresponding to a single input whereas the combinational circuit generates a single output corresponding to a single input.

In a combinational circuit, there is no need for a feedback signal to generate the next output signal but in a sequential circuit, a feedback signal is required for the generation of the next output signal.

The main elementary building block of a combinational circuit is basic logic gates. On the other hand, the elementary building block of a sequential circuit is the flip-flop.

The combinational circuits are mainly used for arithmetic and boolean operations whereas the sequential logic circuits are used for data storing. Even a sequential logical circuit has so many additional functions than a combinational circuit.

The operation of a combinational circuit is very simple as it does not take any feedback signals whereas the operation of a sequential circuit is very complex as it takes feedback signals from its past output and combines them with the input signal to generate the next output signal.

So, now you may understand the exact differences between sequential and combinational circuits. Both are digital logical circuits used for different purposes. Also, note that the sequential circuits require external triggering means they are clock-dependent whereas the combinational circuit does not need any external triggering so they are clock-independent.

Difference Between Combinational and Sequential Circuit Reviewed by Author on January 24, 2022 Rating: 5