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syhaunguyen , 02-17-2016, 10:55 AM

Hi all, I have pcb project.
All diff-pair is connected. but not match impedance (width and gap). I set design rule for diff-pair and run DRC for checking.
What is best way to clear diff-pair routing DRC as well.

Thanks.

mairomaster , 02-17-2016, 01:09 PM

You can easily change the width of single ended tracks after you have done the tracking by selecting them and using the PCB Inspector. However, I am not sure how would this work for differential pairs. With differential signals you would still be able to adjust the width (again with the inspector), but I don't know a way to adjust the gap. You might need to fix the gaps manually after you have the rule. Let see what the others will say.

robertferanec , 02-18-2016, 03:22 AM

@syhaunguyen, we usually re-route them.

It is possible to adjust differential pair impedance the way, that you make tracks thinner (as @mairomaster described). Usually PCB house do it. However, this is not always possible and you may not meet single ended impedance then.

syhaunguyen , 02-18-2016, 03:26 AM

Thanks @robertferanec
I always re route too.