Page 40 - CITS - Electronic Mechanic - TT - 2024
P. 40

ELECTRONICS MECHANIC - CITS



























           Demultiplexer

























           Illustration of demultiplexer
           •  It has one input common data, ‘n’ select lines and ‘m’ output lines.
           •  A demultiplexer performs the reverse operation of a multiplexer i.e. it receives one input and distributes it over
              several outputs.

           •  At a time only one output line is selected by the select lines and the input is transmitted to the selected output
              line.
           •  Relation between ‘n’ output lines and m select lines is as follows:

                                                   n     =     2  m
           1 X 4 Demultiplexer
           •  1 to 4 Demultiplexer has one data input F; select line inputs a,b and four outputs A, B, C &D.
           •  The select lines control the data to be routed. It helps in selecting the output on which the data will be routed.
           Switch Representation

           Based on the switch control, the input is routed to particularoutput.
           Truth table of 1 X 4 demultiplexer
           Boolean Equation
           A= Fb′a′;   B = Fb′a;     C= ba′;       D=Fba
           Working

           •  When ab=”00”, the input data F is routed to the output A

                                                           25
                                    CITS : E & H - Electronics Mechanic - Lesson 9 - 29
   35   36   37   38   39   40   41   42   43   44   45