Typically were does the jitter come from on my clocking signals and how can I fix it?
There can be many sources and we also have to consider that devices themselves have inherent jitter themselves. PCB things like trace length, trace spacing, trace routing. Type of power support, for example lab supply vs. switching supply. MCUs & MPUs have inherent jitter and can be a source of feedback to the power plane of the PCB.
The use of a Jitter Attenuator can smooth / filter out some or all of the noise. One key note is if you use a jitter attenuator that has multiple outputs, then all outputs must be terminated with 50Ohm resistors otherwise they can also cause jitter in the clocking system.
For more information on our Jitter Attenuators please visit https://www.renesas.com/us/en/products/clocks-timing/jitter-attenuators-frequency-translation