What does PLL voltage do?

[JumpingJack]

But how does that relate to half multipliers?

Look this is easy... it is not hard.... but if you can't see it you can't see it....


Take a wave, then superimpose a wave on top of that such that the they both begin and end on zero, that is all you need.


Hang tight, I will do an XLS plot to show you.

EDIT, here you go:




The top 2x example is made by sin(2x) of the input wave, the 2.5 x example is, logically, multiplier 2.5 of the input wave. Both examples shows, in one period of the input wave in each case the nodes match this is what it means to phase lock more or less (over simplified). In one case the node has the waves locked at 0, in phase (both are starting their postive deriviatve), in the other case the node is locked, but the waves are 180 deg out of phase.

Now, this becomes an interesting mental exercise ... design a circuit that will phase lock on 1/2 nodes. Hmmmmm, I would have to think about that one. But if you google phase lock loop multipliers you will turn up oodles of patents.