Layout Matching Problem

[ryusgnal]

Base on note above, current should run in same direction. Is this still matter if I do multifinger and common centroid layout?

 

[OpAmp]

Of course, it does matter. Because the above rule is one of many rules that you should satisfy to have a good matching. Common centroid is in addition to the above rule and it is for eliminating first-order temprature and process variation across the wafer.

OpAmp

 

[hung_wai_ming@hotmail.com]

Can u post the whole lecture here?

 

[ryusgnal]

Of course, it does matter. Because the above rule is one of many rules that you should satisfy to have a good matching. Common centroid is in addition to the above rule and it is for eliminating first-order temprature and process variation across the wafer.

OpAmp

If I want to arrange my differential pair transistor as above, I have to discontinue the active for each block. Because if i don't do that, the current will flow in opposite direction each other. Am I Right?

Added after 2 minutes:

Can u post the whole lecture here?

 

[hung_wai_ming@hotmail.com]

Yes, I think so.
This is the trade-off between area/matching

 

[wonbef]

another layout matching technique is network layout matching. but it is more complicated.

 

[ryusgnal]

another layout matching technique is network layout matching. but it is more complicated.

Dear wonbef,
Do you have any notes about network layout matching? I'm interested to know about it.

 

[fivehunder1]

in the analog layout matching is very important
so thank you

 

[xreaver]

Check the following for analog layout matching docs

 

[hung_wai_ming@hotmail.com]

I would prefer adding a dummy polt in between the "improved" version to improve profiling between the diffusion. also able to complete the diffusion ends with sharp changes from diffusion. I would also add dummy magnet-like POLY to improve POLY end mis-matches.

 

[engrak]

i it do matter

 

[radram]

Can u explain what rules to be followed to obtain good matching like current for matched transistors should be in same direction and adding dummies.

Added after 1 minutes:

Also what is the reason behind the need for the current to be in the same direction?

 

[ryusgnal]

I would also add dummy magnet-like POLY to improve POLY end mis-matches.

Can you explain more about dummy magnet?

 

[fixrouter4400]

hi ryusgnal - please read post on "Matching Layout Techniques" about dummy transistor...but if hung_wai_ming can explain further the magnet-like poly the better.

cheers