Multiplexer (MUX)

Multiplexer (MUX):
It is a combinational logic circuit which directs multiple input lines to a single output line. In other words we can say that multiplexer is a combinational circuit which accepts input from multiple input lines but only have single output line to produce the output. for this purpose it multiplexes all the inputs and select the output using special select lines.

here, 

           number of input lines = 2^N ,where N = number of select lines.

thus, if input lines = 8, select lines are:

                                                           8 = 2³

                                                              = 3 (using above formula).

Multiplexers are also known as MUX. We have following types of multiplexers:

    1)    4 X 1 MUX

    2)    8 X 1 MUX

    3)    16 X 1 MUX

4 X 1 MUX:

It has 4 input lines and 2 select lines.

Truth Table