Fundamental Digital Electronics/Digital DeMultiplexing

Digital demultiplexers
Demultiplexers take one data input and a number of selection inputs, and they have several outputs. They forward the data input to one of the outputs depending on the values of the selection inputs. Demultiplexers are sometimes convenient for designing general purpose logic, because if the demultiplexer's input is always true, the demultiplexer acts as a decoder. This means that any function of the selection bits can be constructed by logically OR-ing the correct set of outputs.


 * Demultiplexer Example01.svg

List of ICs which provide demultiplexing
The 7400 series has several ICs that contain demultiplexer(s):
 * {| class="wikitable"

! S.No. !! IC No. !! Function !! Output State
 * 1
 * 74139
 * Dual 1:4 demux.
 * Output is inverted input
 * 3
 * 74156
 * Dual 1:4 demux.
 * Output is open collector
 * 4
 * 74138
 * 1:8 demux.
 * Output is inverted input
 * 5
 * 74154
 * 1:16 demux.
 * Output is inverted input
 * 6
 * 74159
 * 1:16 demux.
 * Output is open collector and same as input
 * }
 * 6
 * 74159
 * 1:16 demux.
 * Output is open collector and same as input
 * }