What does PLL voltage do?

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The cyan trace is 180 degrees out of phase with the blue trace.

If you were to write the functionality of the blue and green it would look like this:

Blue = sin(x) with x in degrees
Cyan = sin(x+180) with x in degrees

180 is refered to as the phase shift, greek character phi is often used.

A PLL must lock onto a node, the simplest explanation is that for this to occur at the node when the wave forms cross at 0, in the same going direction (this would be in phase), this would result in whole multiples of the output wave form. If the PLL locks at the node where the node is going in opposite directions (negative going), it is out of phase....

This is a simple explanation for it... another way to think about it is that the output wave form is in phase with the input wave form ever 2 periods.

Here is a better example of a 2x PLL locked in phase with an integer multiplier.



Jack

Jack, please correct me if I'm wrong, but I'm pretty sure for the sine graph you posted:

Blue = sin(x) with x in degrees
Cyan = -sin(x) with x in degrees

Now if I remember correctly from trig, wouldn't 180 degrees out of phase actually be f(x)=sin(x)+180 or f(x)=sin(x+180).... I don't remember which it is. But I'm pretty sure I'm right on the first part of -sin(x) and sin(x)...