Demultiplexer(DEMUX)

Last Updated : 4 Feb, 2026

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.

General Block Diagram Of A DEMUX

Demulyiplexer
DEMUX

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.

demux2
1:4 DEMUX

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

Selection InputsOutputs
S1S0Y3Y2Y1Y0
00000I
0100I0
100I00
11I000

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.

demux_3
1:8 DEMUX

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

Selection InputsOutputs
S2S1S0Y7Y6Y5Y4Y3Y2Y1Y0
0000000000I
001000000I0
01000000I00
0110000I000
100000I0000
10100I00000
1100I000000
111I0000000

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.

demux_4
1:16 DEMUX

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

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0

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0

0

A

0

0

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0

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0

0

1

0

0

0

0

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A

0

0

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1

0

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1

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A

0

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1

0

1

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A

0

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1

1

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A

0

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1

1

0

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A

0

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0

0

0

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1

1

0

1

0

0

A

0

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1

1

1

0

0

A

0

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1

1

1

A

0

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0

0

0

0

0

0

0

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.

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