quick.gif

space2.gif

space2.gif

space2.gif

space2.gif

space2.gif

space2.gif

space2.gif

   

space.gif

   

space.gif

  ../images/main/bullet_green_ball.gif De-multiplexers

They are digital switches which connect data from one input source to one of n outputs.

Usually implemented by using n-to-2n binary decoders where the decoder enable line is used for data input of the de-multiplexer.

   

space.gif

The figure below shows a de-multiplexer block diagram which has got s-bits-wide select input, one b-bits-wide data input and n b-bits-wide outputs.

   

space.gif

../images/digital/demux_blk.gif
   

space.gif

   

space.gif

  ../images/main/bulllet_4dots_orange.gif Mechanical Equivalent of a De-Multiplexer

The operation of a de-multiplexer can be better explained using a mechanical switch as shown in the figure below. This rotary switch can touch any of the outputs, which is connected to the input. As you can see at any given point of time only one output gets connected to input.

   

space.gif

../images/digital/demux_mecha.gif
   

space.gif

1-bit 4-output de-multiplexer using a 2x4 binary decoder.

   

space.gif

../images/digital/demux_using_2x4_decoder.gif
   

space.gif

  ../images/main/bulllet_4dots_orange.gif Example: 1-to-4 De-multiplexer
   

space.gif

Symbol

   

space.gif

../images/digital/demux.gif
   

space.gif

Truth Table

S1

S0

F0

F1

F2

F3

0

0

D

0

0

0

0

1

0

D

0

0

1

0

0

0

D

0

1

1

0

0

0

D

   

space.gif

   

space.gif

   

space.gif

   

space.gif

space2.gif

space2.gif

space2.gif

space2.gif

space2.gif

  

Copyright © 1998-2014

Deepak Kumar Tala - All rights reserved

Do you have any Comment? mail me at:deepak@asic-world.com