Clock jitter - ppm, ui, ps
The &quot;Good News&quot; first: I can save you using an online calculator.
&quot;ppm&quot; is for &quot;parts per million&quot;; so 50 ppm simply means a relative error of 50·10⁻⁶; at 200 MHz, that means 200·10⁶ Hz · 50·10⁻⁶ = 10000 Hz. It's that simple!
Bad news:
Doesn't have anything to do with jitter.
Your clock could be running at, say 200.010 MHz (which is just barely within the error specified by the ppm accuracy) perfectly stable – and have zero jitter.
Or it could be running at an average of 200.000000 MHz, but make random phase jumps at arbitrary times and have a gigantic jitter.
Your specification of ppm describes an overall accuracy. As in &quot;when you use this oscillator, its frequency is going to be within nominal frequency +- x ppm&quot;.
What it doesn't tell you at all is how much the oscillator varies within that range during use.
But jitter is just that: how much does the point at which, for example, we observe a positive-going zero crossing, change. How much does it jump around?
You'll need a different specification than just for the overall accuracy.
Typically, the specification you're looking for is &quot;phase noise over frequencies&quot;, or &quot;Allan variance&quot;/&quot;Allan deviation&quot;, both from which you can calculate the energy of the phase noise, which is essentially the variance of jittering, and that's the square of the standard deviation of jitter; it's its RMS value.
For more in-depth &quot;how to phase noise to jitter&quot;: This analog devices tutorial seems appropriate.
For &quot;how to Allan variance to jitter&quot;: Bigger topic, I think if you have an oscillator device that specifies Allan deviation/variance instead of phase noise, you'd probably have to understand the wikipedia article on the topic, anyway, so if that's the case, I'd encourage you to ask a new question describing where your 200 MHz come from, what you're doing with them and your PLL's frequency and so on.