13-04-2013, 04:28 PM
DESIGN AND IMPLEMENTATION OF MULTIPLEXER AND DEMULTIPLEXER
AIM:
To design and implement the 4:1 multiplexer and 1:4 demultiplexer using digital logic
gates.
THEORY:
MULTIPLEXER:
A digital multiplexer is a combinational circuit that selects binary information from one
of the binary input lines and directs to a single output. The set of particular input line is
controlled by a set of selection lines. A digital multiplexer is a combinational circuit that selects
binary information from one of many input lines and directs it to a single output line. The
selection of a particular input line is controlled by a set of selection lines. Normally there are 2n
input line and n selection lines whose bit combination determine which input is selected.
DE-MULTIPLEXER:
A demultiplexer is a combinational circuit that performs the reverse operation of a multiplexer. It receives information on a single line and transmits the information to 2n possible outputs. The data input to the de-multiplexer can be rated to any of the output. Hence the circuit is referred to as data distributor. Decoder can also be used as demultiplexer. In the 1: 4 demultiplexer circuit, the data input line goes to all of the AND gates. The data select lines enable only one gate at a time and the data on the data input line will pass through the selected gate to the associated data output line.
PROCEDURE:
1. Connections are given as per the circuit diagram on the bread board.
2. The power supply is switched ON and set a voltage of 5 Volts.
3. If the input to be given to a gate is logic ‘1’ then it is connected to +5 Volts and if the input to be given to the gate is logic ‘0’ then the particular input terminal is connected to ground.
4. Truth tables of 4:1 multiplexer and 1:4 demultiplexer are verified.
5. If the output is logic ‘1’ then the LED glows, if the output is logic ‘0’ then the LED does not glow.