Multiplexers (MUX) and demultiplexers (DEMUX)

Multiplexers

Multiplexer is a special type of combinational circuit. It is a circuit that accept many input but give only one output.

A data selector, commonly called a Multiplexer, shortened to "Mux" or "MPX", are combinational logic switching devices that operate like a very fast acting multiple position rotary switch.

 They connect or control, multiple input lines called "Channels" consisting of either 2, 4, 8 or 16 individual inputs, one at a time to an output.

There are n-data inputs, one output and m select inputs with 2m = n. It is a digital circuit which selects one of the n data inputs and routes it to the output.

Following are Multiplexers come in multiple variations

•2 : 1 multiplexer

•4 : 1 multiplexer

•16 : 1 multiplexer

•32 : 1 multiplexer

Demultiplexers

A demultiplexer performs the reverse operation of a multiplexer i.e. it receives one input and distributes it over several outputs.

It has only one input, n outputs, m select input. At a time only one output line is selected by the select lines and the input is transmitted to the selected output line.

The demultiplexer takes one single input data line and then switches it to any one of a number of individual output lines one at a time.

The demultiplexer converts a serial data signal at the input to a parallel data at its output lines as shown below.

Following are the Demultiplexers come in multiple variations

•1 : 2 demultiplexer

•1 : 4 demultiplexer

•1 : 16 demultiplexer

•1 : 32 demultiplexer

A de-multiplexer is equivalent to a single pole multiple way switch.A de-multiplexer function exactly in the reverse of  a multiplexer, that is a de-multiplexer accepts only one input and gives many outputs. Generally multiplexer and de-multiplexer are used together, because of the communication systems are bi directional.