A demultiplexer, also known as a data distributor, is a combinational circuit that takes a single input and forwards it to one of multiple outputs based on the select signal. It has one input line, M select lines, and N output lines. The select input determines which output line the input signal will be forwarded to.
The most commonly used demultiplexer is the 1-to-2 demultiplexer, which distributes a single input line to one of two output lines based on the value of the select input. The implementation of a 1-to-2 demultiplexer is shown below:
In this circuit, there is one input line A, two output lines Y0 and Y1, and a select input S. The select input controls the distribution of the input signal, with S=0 forwarding the input to output line Y0 and S=1 forwarding the input to output line Y1.
The implementation of a 1-to-4 demultiplexer is shown below:
In this circuit, there is one input line A, four output lines Y0 to Y3, and two select input lines S0 and S1. The select inputs are used to determine which output line the input signal will be forwarded to. The demultiplexer selects one of the output lines based on the binary value of the select inputs.
Demultiplexers have various applications in digital circuits, such as in memory, I/O interfaces, and digital signal processing.