IC 74154

A demultiplexer does the reverse operation of a multiplexer,it has one input and many outputs.it can be either 1 to 4,1to 8,1 to 16 like that.
The demultiplexer is the inverse of the multiplexer, in that it takes a single data input and n address inputs. It has 2ⁿ outputs. The address input determine which data output is going to have the same value as the data input. The other data outputs will have the value A logic circuit that takes a single input and sends it to one of several outputs. In networking, it is used to describe a device that receives a transmission of several signals over a single line and can properly decode the single line signal into multiple signals.
0.
Here is an abbreviated truth table for the demultiplexer. We could have given the full table since it has only 16 rows, but we will use the same convention as for the multiplexer where we abbreviated the values of the data inputs.

  a2 a1 a0  d | x7 x6 x5 x4 x3 x2 x1 x0
-------------------------------------
 0  0  0  c |  0  0  0  0  0  0  0  c
 0  0  1  c |  0  0  0  0  0  0  c  0
 0  1  0  c |  0  0  0  0  0  c  0  0
 0  1  1  c |  0  0  0  0  c  0  0  0
 1  0  0  c |  0  0  0  c  0  0  0  0
 1  0  1  c |  0  0  c  0  0  0  0  0
 1  1  0  c |  0  c  0  0  0  0  0  0
 1  1  1  c |  c  0  0  0  0  0  0  0

Here is one possible circuit diagram for the demultiplexer:

IC74154 is a i1 to 16 line multiplexer .It has a data input d and 16 outputs Yo through Y15 and can achieve a low strobe output .T he data select inputs abcd decides the output pin at which the data should be available. For example if ABCD is 0001,data input will be available at Y1

74154
1-of-16 inverting decoder/demultiplexer PINOUT

   +----------+
/Y0 |1  +--+ 24| VCC
/Y1 |2       23| S0
/Y2 |3       22| S1
/Y3 |4       21| S2
/Y4 |5       20| S3
/Y5 |6   74  19| /EN2
/Y6 |7  154  18| /EN1
/Y7 |8       17| /Y15
/Y8 |9       16| /Y14
/Y9 |10      15| /Y13
/Y10 |11      14| /Y12
GND |12      13| /Y11
   +----------+