Demultiplexers

A demultiplexer (data distributor) will select a specific output data transmission path from many for the input data to be sent to.
The demultiplexer has several control select lines which are used to determine the selected output transmission path.

The number of data outputs is equal to 2^N where N is the number of control select leads.
The 74139 is a 1-of-4 decoder that can also be used as a demultiplexer.
To use the 74139 as a demultiplexer, connect the incoming data to the enable input and use the A0 and A1 inputs as the control select lines.
The 74154 1-of-16 decoder can also be used as a 16 line demultiplexer.
Several CMOS chips use a transmission gate as part of the multiplexer/demultiplexer. This means that the gate is bidirectional and can also handle AC signals as well as binary 1's and 0's.