Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
can any one tell me what is the exact purpose of matching mos? i know it is for matching the electrical charactiristics. But what its impact on outputs?
can you please elaborate what do you mean by current and voltage offset? Is this two the solo reason that we do matching? So for matching two transistor their W/L should be the same?
Should have the same dimensions of strips, the same neighborhood and be large enough. Transistors with pocket/halo implants has some additional "rules"
Look for articles of Lakshmikumar, Pelgrom, Bastos and Drennan about matching.
Differential-pairs (e.g. for op-amps or OTAs) and current-mirrors are more examples of where matching can be critical.
IC processing cannot create perfect uniformity or accuracy of lithography in both horizontal and vertical directions, and there can be temperature variations across the die.
Simply matching W & L is not good enough (and bird's-beak effects also become significant at minimum L, see https://www.edaboard.com/threads/157753/ ).
That is why special rules-of-thumb are used in both sizings and layout orientations and placements of transistors to overcome these effects.
Common Centroid & Interdigitation are examples of such techniques (for example, see https://www.edaboard.com/threads/65645/ ).
And I'm sure you'd find more info if you web-search for the terms provided in all these replies.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
