Differential Via Specifications Calculations

[harshal_pwr]

Hello,

I am wondering if there is any specific via requirement for differential pair traces.

How can we determine the hole size, via diameter and spacing for a diff pair?

Your responses are much appreciated.

Thank you

- Harshal

[mairomaster]

You don't need to do anything special. Just use normal signal vias as with the rest of the board and place them at a sensible distance from each other.

That should work fine with anything in the sub 1 GHz range. If you work with higher frequencies you might need to be careful with the vias as well.

[robertferanec]

Same here.

Normally we use minimum VIA of our design for all signals (including differential pair signals) and we have never had any problems (even if they were used in interfaces such PCIE, GbE, LVDS, HDMI, ...). By minimum VIA I mean the minimum VIA which was possible to make by specific PCB technology which was used for specific project.

To give you an example, we often use through hole VIA with 0.45mm ring and 0.2 mm hole.

[harshal_pwr]

Thank you Mairomaster and Robert.

- Harshal