(MUX) A digital multiplexer is a circuit that selects binary information from one of several (INPUTS) inputs lines and directs it to a single line for transmission to common destination as called (OUTPUT). The selection of a particular 4-input lines is controlled by a set of selection lines (DATA SELECT) data select.
The multiplexer (MUX) has several data input lines and a single output line. It also has data select input that helps to choose any one of the inputs to be switched to the outputs. Below the simple mechanical arrangement gives guide line to understand how the multiplexer is working with Data selector.
Simple Mechanical Switch animation
The two-bit binary number can be used as data-select. The 4 or 8 inputs are selected by S1, S2 as binary number, it select corresponding input switch we wants.
Data Selection Animation
Above animation the inputs of X0, X1, X3, X5, X7 are connected through 5v power supply and X2, X4, X6 are with ground, so that output of multiplexer LED connected with RESISTOR goes to ON or OFF with respect to inputs and Data selection of AD0, AD1, AD2.
A demultiplexer (DEMUX) performs the reverse action of a multiplexer, It takes data from one line (single input) and distributes it to a give number of output lines. Thus the DEMUX has one input and many output.