alecsander
Junior Member level 3
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layout matching techniques
Hi.
Does anyone know a book / paper that describes avdanced matching techniques from layout perspective?
This is the question. Now, details.
When designing a layout for a current mirror, for example, there is a large number of MOS transistors involved. The books i read briefly describe matching of these transistors. I give you the issue that conviced me to open this topic; for a common centroid layout, din all the books, the following pattern for matching is described:
ABAABA
BABBAB
BABBAB
ABAABA
Looks fine. BUT, i just found out that it is NOT good. A better one is:
ABABAB
BABABA
BABABA
ABABAB
In the first one, A dog-bone arrangement is the same in the left part and in the right part, but A-MOS and B-MOS do not have the same stress gradient.
In the second, A dog-bone in the left equals the B dog - bone in the right.
This is only an example. My problem is that i cannot find theory explaining these issues.
So, does anyone know books like this? Thank you very much.
Hi.
Does anyone know a book / paper that describes avdanced matching techniques from layout perspective?
This is the question. Now, details.
When designing a layout for a current mirror, for example, there is a large number of MOS transistors involved. The books i read briefly describe matching of these transistors. I give you the issue that conviced me to open this topic; for a common centroid layout, din all the books, the following pattern for matching is described:
ABAABA
BABBAB
BABBAB
ABAABA
Looks fine. BUT, i just found out that it is NOT good. A better one is:
ABABAB
BABABA
BABABA
ABABAB
In the first one, A dog-bone arrangement is the same in the left part and in the right part, but A-MOS and B-MOS do not have the same stress gradient.
In the second, A dog-bone in the left equals the B dog - bone in the right.
This is only an example. My problem is that i cannot find theory explaining these issues.
So, does anyone know books like this? Thank you very much.