Differential Clock - why?

[ivlsi]

Hi All,

Why a differential clock is used? I understand that it's probably needed for a protection from a noise, but anyway, are there another reasons?

Thank you!

 

[D.A.(Tony)Stewart]

• low skew between opposite edges is critical in some timing applications.
• controlled impedance on both limits ringing and low skew cancels EMI of edges.

 

[imbichie]

There are several advantages to using differential signaling. Three of the most important are these:
(1) Differential receivers reject common mode noise due to skew, power supply noise, interference, etc.
(2) Differential signals effectively double the voltage swing at the differential receiver increasing S/N.
(3) Well balanced and terminated differential transmission lines generate less EMI.
For these reasons, differential output formats are typically selected in high frequency and/or low jitter applications.
Please go to below link for more details.

https://www.ultracad.com/articles/differentialsignals.pdf