Difference Between Sequential And Combinational Circuits
Combinational circuit is a circuit whose output is dependent only on the inputs at the same instant of time where as a sequential circuit is a circuit whose output does not only depend on the present inputs but also on the past history of inputs.
A sequential circuit simply consists of combinational circuit and memory elements are connected to it to form a feedback path as shown in the block diagram below:
|1.||It contains no memory elements||It contains memory elements|
|2.||The present value of it’s outputs are determined solely by the present values of it’s inputs||The present value of it’s outputs are determined by the present value of it’s inputs and it’s past state|
|3.||It’s behavior is described by the set of output functions||It’s behavior is described by the set of next-state(memory) functions and the set of output functions|
A sequential circuit can further be categorized into Synchronous and Asynchronous. You might also want to see the difference between synchronous and asynchronous flip flops.