# Dmultiplexer truth table and boolean expression

As the title says I have problem with understanding how to make the truth table for demultiplexer and how to make a Boolean expression from it. The thing that bothers me is how to make a truth table with more than one outputs. I search through google and I've found this answer

However I can't understand it, and I have no idea what to do. Any help is appreciated.

I got it, in case anybody came here with search engine, read the comments, and don't Or(+) the outputs.

• Make a separate truth table for each output. As the set of input patterns is the same for each table, you can then combine all your tables into one, with the same inputs, and a separate column for each output.
– user16324
Commented Sep 6, 2015 at 20:14
• And how can I draw the Boolean expression them. I mean in one case a will be = to 1, in the other b will be = to 1, is another both of them will be 1? And then I have to proceed like turning truth table with one input into Boolean expression? Commented Sep 6, 2015 at 20:21
• You will need a Boolean equation for each output based upon the inputs. Commented Sep 6, 2015 at 20:30
• And then I have just to Or(+) them? Commented Sep 6, 2015 at 20:33
• Depends. Do you or your outputs in the final circuit? Commented Sep 6, 2015 at 20:46