Sequential circuits

Sequential switching circuits are those whose output levels at any instant of time are dependent not only on the levels present at the inputs at that time, but also on the state of the circuit, i.e on the prior input level conditions. The past history is provided by feedback from the output back to the input. It means that sequential switching circuits have memory. Sequential circuits are thus made of combinational circuits and memory elements. The past history is provided by feedback from the output back to the input. Figure  shows the block diagram of a sequential circuit.
Sequential circuits
Sequential circuits


A memory element is a device which can store information in terms of 1 or 0 and its state can be modified by clock signal and data inputs. A flipflop is one bit memory element which can store 1 or 0. Flipflop is an electronic circuit or device which is used to store data in binary form.

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