doubt on common centroid and interdigitation

[Deepthi Palavelli]

hi...!
what happen if i use commoncentroid for differential pair and interdigitation for current mirrors?

thanks in advance...

 

[kenambo]

Hi,

Generally we use interdigitation for diff pair.. But if more devices are used and neet to be matched then we have to go for common centroid configuration,....
Because,
more devices makes interdigitation somewhat lenghtier.... This makes process variations affect performence of devices......
At the same time , in common centroid matching the circuit connection is somewhat complex than interdigitation...

And for current mirrors also, interdigitation is best matching , because.. interdigitation provide good DC conditions which is the need for a current mirror..

Thanks,,