Sequential circuits are mainly used in flip-flops, latches and registers.As against sequential circuits can store a specific amount of data. The combinational circuit does not have any potential to store data.As mentioned above the combinational circuits uses the latest input for generating the output whereas sequential input decides the output of the given input by considering the previous output also.Key Differences Between Combinational and Sequential Circuit The circuit is considered as synchronous when the internal state of the machine alters at the particular time driven by a clock. The sequential circuits are categorised in two ways, synchronous and asynchronous circuits. These inputs changes from one of the two states.

There are various devices which implement sequential circuits such as latches, flip-flop, and registers. This memory device can be made up of the simple OR gate. For example, it can remember which logic level 0 or 1 is connected to its input and employ the fact at the output also. This means that the sequential circuits contain an amount of memory to store the immediate results. The characteristic of this circuit is that the state of output changes according to the sequence of the input has been inserted. Boolean equations: The output signals are expressed in the form of the boolean function of input signals.Ī sequential circuit is a class of circuits where the outcome depends on both the present input and past outputs.Graphical symbol: Shows the linked layout of the gates.Truth table: It generates the ‘m’ number of binary output signals for the set of 2 n input signals.The significant characteristics of the combinational circuit It implements the crucial functions of a digital computer. BCD and 7 segments are the code converter circuits.Ĭommonly, a combination circuit comprised of n number of binary inputs and m number of binary outputs. Similarly, data transmission circuits are multiplexers, demultiplexers, encoders, decoders and so on. The circuits included in the arithmetic and logic circuits are the adders, subtractors, comparators, PLDs, etcetera. There are three variations of the combinational logic circuits – arithmetic and logical functions, data transmission and code converters. In these circuits, the output generated at that time would depend on the input of the particular time. One of the typical examples of the combinational circuit is the decoder which is used to transform the binary code data into the decimal code data. As shown in the below-given diagram of the combinational circuit the output lines immediately follow the input lines. The basic AND, OR and NOT or universal gates NAND and NOR are the fundamental building blocks of the combinational circuit. A combinational circuit is built up of the linked collection of several gates which produces output specific to the input at that instant.

Combinational and sequential circuits