Digital circuits are electronic circuits that use discrete voltage levels to represent data (binary digits), as opposed to analogue circuits, where a continuous range of voltage is used. Their advantage is that they can process information more quickly and efficiently by not having to convert the input signal into an analogue signal and then into a digital signal.
Digital circuits are made from large scale integrated (LSI) or very large scale integrated (VLSI) circuits. These are constructed from many transistors on a single chip of semiconductor material. Digital integrated circuits are a subset of mixed-signal integrated circuits.
Digital circuits use binary logic : the basic unit of information ( bit ) can only be a ' 1 ' or a ' 0 '. Digital circuit design draws on all the other branches of electrical engineering, such as electric power, electromagnetic theory, signal processing and integrated circuit manufacturing. Digital circuits are designed using combinational and sequential logic .