# Constructing a 4-way multiplexer composed of 2-way multiplexers

I've constructed a schematic of a 2-way multiplexer, and also have made a 4-way one (and have a good idea of how to make 8, 16, etc. ones).

However, my 4-way isn't a composition of 2-way multiplexers, and my goal is to make it as "composed" (for lack of better terminology; I know there's a word, but a brain fart has fogged my memory :)) as possible.

How (if possible) can I build a 4-way (and thus 8, 16, etc.) multiplexer out of 2-way multiplexers?

• See the mux as a split of two branches. If you need four branches at the end of the tree, how does the tree look like? – dim Dec 21 '16 at 21:17