The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl Measurements >> Other Measurements >> mismatch analysis https://designers-guide.org/forum/YaBB.pl?num=1178089042 Message started by Pravinkumar on May 1st, 2007, 11:57pm |
Title: mismatch analysis Post by Pravinkumar on May 1st, 2007, 11:57pm Hi all, Am trying to find mismatch in current mirrors through DC analysis. I try to measure the current output by varying the three parameters w, l and vtho of the key transistorsm in the current mirror. I am able to sweep the two component parametrs w and l. Since vtho is a model parameter am not able to introduce mismatch to it. Is there any way to declare it as a variable so that i can use it as another sweep parameter? Is it like the pdk should support the variations of the vtho? any suggestions?????? Am using spectre simulator. Thanks in advance. PS: No model files available to run monte Carlo or dcmatch analysis. |
Title: Re: mismatch analysis Post by ACWWong on May 2nd, 2007, 8:04am A simple (but crude) method would be to introduce a voltage source in the gate of the transistor to sweep the impact of vgs mismatch, which is correlated to threshold mismatch. |
Title: Re: mismatch analysis Post by John O Donovan on May 2nd, 2007, 9:34am Hi, If you are using BSIM4 or BSIM3v3 models, then there are instance parameters for doing this in Spectre. You can use delvto shift in zer0-bias threshold voltage vth0. delk1 shift in body bias coefficient k1. delnfct shift in subthreshold swing factor nfactor. You can find descriptions in 'spectre -h' Regards, John |
Title: Re: mismatch analysis Post by Andrew Beckett on May 8th, 2007, 1:41pm There's also spectre's dcmatch analysis (see spectre -h dcmatch for more details). There are parameters in bsim4 and bsim3v3 (and some other models too), for example: Code:
Regards, Andrew. |
The Designer's Guide Community Forum » Powered by YaBB 2.2.2! YaBB © 2000-2008. All Rights Reserved. |