diego.fan
Member level 3
Hi, may I ask a question about the connection of common centroid? I worked as radio frequency Engineer (1~2GHz)before. We never cross two RF traces in adjacent metals and always use a ground between them.
Now I'm doing the layout of IC with tens of KHz. I search in this forum and found many people suggest common centroid to do the matching, especially in input differential pair.
But common centroid has a big problem in connection. Too many lines cross coupling. First question: I don't know what's effect it will cause? only more parasite coupling to slow the speed? In RF if this condition happens, we will see a big problem in EMC and intermodulation.
Second question: For example, I make a draft drawing on the below pattern. Do you has some good ways to arrange these lines?
ABBAABBA
BAABBAAB
BAABBAAB
ABBAABBA
However Interdigitated is not suitable for me because my transistor width is a little long, it will be a lonnnnnnnng line if Interdigitated is used.
Now I'm doing the layout of IC with tens of KHz. I search in this forum and found many people suggest common centroid to do the matching, especially in input differential pair.
But common centroid has a big problem in connection. Too many lines cross coupling. First question: I don't know what's effect it will cause? only more parasite coupling to slow the speed? In RF if this condition happens, we will see a big problem in EMC and intermodulation.
Second question: For example, I make a draft drawing on the below pattern. Do you has some good ways to arrange these lines?
ABBAABBA
BAABBAAB
BAABBAAB
ABBAABBA
However Interdigitated is not suitable for me because my transistor width is a little long, it will be a lonnnnnnnng line if Interdigitated is used.