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mulfycrowh , 08-25-2023, 12:38 PM

Hi everyone,

I have a design with several differential pairs.
After changing the stackup and then the impedances, I would like Altium to trigger errors about width and space constraint on differential pairs.
Just to be sure not to forget one differential pair to be retraced.

How do you manage that?

Thanks.

WhoKnewKnows , 08-25-2023, 12:47 PM

Tools>Design rule check

Confirm rules to check section is filled appropriately

Click Run Design Rule Check button

mulfycrowh , 08-25-2023, 01:43 PM

With design rules set as you can see in the screenshot, AD doesn't trigger any issue on width or space for differential pairs.
Why?

qdrives , 08-25-2023, 02:32 PM

Could it be that the "batch" check in the DRC is turned off?

mulfycrowh , 08-25-2023, 03:02 PM

I have nothing checked except batch for width

mulfycrowh , 08-25-2023, 03:06 PM

For single tracks, it is OK because there is a rule for width.
Should we implement a similar rule for differential pairs with width and space?

mulfycrowh , 08-26-2023, 12:42 PM

I think I found what I wanted: you have to check Differential Pairs Routing in the Design Rule Checker.

qdrives , 08-26-2023, 12:57 PM

Yes, that is what I was alluding to. By default it is off, that means Altium does not flag traces that do not comply, only during (online) does it do that.