Demultiplexer

combinatorial-logic

Definition

Demultiplexer

A demultiplexer (DMX) is a combinatorial logic circuit is the inverse of a multiplexer. It is a combinatorial logic circuit that takes a single input signal and routes it to one of many output lines based on the values of control or selection signals.

Example

The following example shows a 1-to-4 demultiplexer which has enable input , two selection lines and four outputs .

As the table below shows, similar to the multiplexer, the demultiplexer chooses its output based on the decimal number representation of the binary word and sets (the enable signal.)

However, in contrast to the multiplexer, the demultiplexer also receives an enable signal which, when set to , all are zero regardless of the selection line values.

			0	0	0	0
			0	0	0	1
			0	0	1	0
			0	1	0	0
			1	0	0	0

Example: If and , then the demultiplexer selects since the binary word is equal to , which is equal to in the decimal system.