|IC Number||IC Name|
|74LS04||Hex Inverting Gates|
|74LS11||Triple 3-input AND Gates|
De-Multiplexer - The demultiplexer is a combinational logic circuit designed to switch one common input line to one of several separate output lines. The data distributor, known more commonly as a Demultiplexer or “Demux” for short, is the exact opposite of the Multiplexer we saw in the previous tutorial. The demultiplexer takes one single input data line and then switches it to any one of a number of individual output lines one at a time. The demultiplexer converts a serial data signal at the input to a parallel data at its output lines as shown below.
The function of the Demultiplexer is to switch one common data input line to any one of the 4 output data lines A to D in our example above. As with the multiplexer the individual solid state switches are selected by the binary input address code on the output select pins “a” and “b” as shown.Demultiplexer Output Line Selection :
As with the previous multiplexer circuit, adding more address line inputs it is possible to switch more outputs giving a 1-to-2n data line outputs.
Some standard demultiplexer IC ́s also have an additional “enable output” pin which disables or prevents the input from being passed to the selected output. Also some have latches built into their outputs to maintain the output logic level after the address inputs have been changed.
However, in standard decoder type circuits the address input will determine which single data output will have the same value as the data input with all other data outputs having the value of logic “0”.
The Demultiplexer SymbolThe Demultiplexer Symbol