What is Demultiplexer(DEMUX)?

Last Updated : 29 Jul, 2024

DEMUX or De-Multiplexer is a data distributor combinational circuit. It works in a reverse way of the Multiplexer. The DEMUX has 1 input port and 2^n output lines. Here n signifies the selection line for a DEMUX. As per the selection line value, the DEMUX input lines will be connected to receive the output. Demultiplexer receives digital information from a single source and converts it into several sources.

In this article, we are going to have a detailed discussion on the Applications of DEMUX.

Table of Content

What Is A DEMUX?

Advantages and Disadvantages of the DEMUX

What is a DEMUX?

The DEMUX is a digital information processor. It takes input from one source and also converts the data to transmit towards various sources. The demultiplexer has one data input line. The demultiplexer has several control lines (also known as select lines). These lines determine to which output the input data should be sent. The number of control lines determines the number of output lines.

Let us discuss the DEMUX with the attached information.

General Block Diagram Of A DEMUX

Here is the basic block diagram of a DEMUX as mentioned below.

Truth Table Of A 1X4 DEMUX

A 1x4 DEMUX has only one input which is denoted as I. There are two selection lines i.e. S1 and S0. At last, the DEMUX has output lines including Y3, Y2, Y1 &Y0. Here is the 1x4 DEMUX with diagram as mentioned below.

Now let us discuss the truth table of the 1x4 DEMUX as mentioned below.

Selection Inputs		Outputs
S₁	S₀	Y₃	Y₂	Y₁	Y₀
0	0	0	0	0	I
0	1	0	0	I	0
1	0	0	I	0	0
1	1	I	0	0	0

Truth Table Of A 1x8 De-Multiplexer

The 1x8 DEMUX was designed by using two DEMUX. They are the two 1x4 DEMUX and one 1x2 DEMUX. The 1x8 DEMUX contains two input lines with four outputs. Let us see the block diagram of the 1x8 DEMUX as mentioned below.

Here is the 1x8 DEMUX truth table as mentioned below.

Selection Inputs			Outputs
S₂	S₁	S₀	Y₇	Y₆	Y₅	Y₄	Y₃	Y₂	Y₁	Y₀
0	0	0	0	0	0	0	0	0	0	I
0	0	1	0	0	0	0	0	0	I	0
0	1	0	0	0	0	0	0	I	0	0
0	1	1	0	0	0	0	I	0	0	0
1	0	0	0	0	0	I	0	0	0	0
1	0	1	0	0	I	0	0	0	0	0
1	1	0	0	I	0	0	0	0	0	0
1	1	1	I	0	0	0	0	0	0	0

Truth Table Of A 1x16 De-Multiplexer

The 1x16 DEMUX was designed by using the two 1x8 DEMUX and one 1x2 DEMUX. The 1x16 DEMUX have two input lines. It has eight outputs. Let us see the block diagram of the 1x16 DEMUX as mentioned below.

Here is the 1x16 DEMUX truth table as mentioned below:

SELECTION INPUTS				OUTPUTS
S₃	S₂	S₁	S₀	Y₁₅	Y₁₄	Y₁₃	Y₁₂	Y₁₁	Y₁₀	Y₉	Y₈	Y₇	Y₆	Y₅	Y₄	Y₃	Y₂	Y₁	Y₀
0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	A
0	0	0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	A	0
0	0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	A	0	0
0	0	1	1	0	0	0	0	0	0	0	0	0	0	0	0	A	0	0	0
0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	A	0	0	0	0
0	1	0	1	0	0	0	0	0	0	0	0	0	0	A	0	0	0	0	0
0	1	1	0	0	0	0	0	0	0	0	0	0	A	0	0	0	0	0	0
0	1	1	1	0	0	0	0	0	0	0	0	A	0	0	0	0	0	0	0
1	0	0	0	0	0	0	0	0	0	0	A	0	0	0	0	0	0	0	0
1	0	0	1	0	0	0	0	0	0	A	0	0	0	0	0	0	0	0	0
1	0	1	0	0	0	0	0	0	A	0	0	0	0	0	0	0	0	0	0
1	0	1	1	0	0	0	0	A	0	0	0	0	0	0	0	0	0	0	0
1	1	0	0	0	0	0	A	0	0	0	0	0	0	0	0	0	0	0	0
1	1	0	1	0	0	A	0	0	0	0	0	0	0	0	0	0	0	0	0
1	1	1	0	0	A	0	0	0	0	0	0	0	0	0	0	0	0	0	0
1	1	1	1	A	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

Advantages and Disadvantages of the DEMUX

Now, we are going to discuss the advantages and disadvantages of the DEMUX as mentioned below.

Advantages of the DEMUX

The DEMUX increases the efficiency of the particular communication system as it takes data from a specific input source and distributes it to different sources.
The DEMUX helps to separate the different signals from the mixed data sources. Then it distributes these data to different sources.
DEMUX can decode the signal outputs of the multiplexer, as the system works in a reverse way of the MUX.

Disadvantages of the DEMUX

The DEMUX may cause a wastage of bandwidth as it distributes the refined data in different channels. These channels can overlap with each other which leads to the loss of signal.
The DEMUX may cause problems in the synchronization of signals. The data channels can overlap with each other which leads to the delay in the whole process.

Applications of DEMUX

DEMUXs are majorly used to design the ALU circuits and parallel data segments.
The DEMUXs convert the output of the MUX into the actual input. On the receiver end, the DEMUX can be used to verify the original form of the data to carry out the entire communication process.
DEMUX helps to save the output. The output generally saved to the ALU. The output will be saved in the registers and the various storage units of the system.
Each DEMUX has a connection with multiple registers which helps to store the processed data into it.
The counterpart of the DEMUX regulates the data signal at the output stage of the DEMUX operation. These data can be retrieved later to read out parallelly.
In the audio or video system, the DEMUX distributes them in different channels. In broadcasting, the DEMUX separates the composite signal into an individual one.

Conclusion

De-Multiplexer is a data distributor combinational circuit. It works in a reverse way of the Multiplexer. The DEMUX has 1 input port and 2^n output lines. The DEMUX increases the efficiency of the particular communication system as it takes data from a specific input source and distributes it to different sources. But the DEMUX may cause a wastage of bandwidth as it distributes the refined data in different channels. These channels can overlap with each other which leads to the loss of signal. DEMUX helps to save the output of the ALU. The output will be saved in the registers and the various storage units of the system.