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https://designers-guide.org/forum/YaBB.pl Modeling >> Semiconductor Devices >> what is the spectre format of mos transistors ? &n https://designers-guide.org/forum/YaBB.pl?num=1142847763 Message started by zhonghan on Mar 20th, 2006, 1:42am |
Title: what is the spectre format of mos transistors ? &n Post by zhonghan on Mar 20th, 2006, 1:42am i just want to write a simplest spectre model by myself. I know the format in Hspice , like .model mn nmos vth0=0.7 gamma=0.4 lambda=0.05. what is the coresponding format in spectre( incuding version )? Then how to cite this model in spectre , I know " .lib 'path' corner " in HSPICE is just ok . |
Title: Re: what is the spectre format of mos transistors Post by Geoffrey_Coram on Mar 20th, 2006, 4:15am Spectre can parse Spice syntax, so you should be able to use the HSpice-style .model card -- particularly if you're using the .lib statement, which is also Spice. We usually use Spectre format: simulator lang=spectre model mn mos1 type=n vto=0.7 gamma=0.4 lambda=0.05 What LEVEL are you using? vth0 is a BSIM3/4 parameter (level=1 uses vto), but gamma is a level=1 or level=3 parameter (bsim3v3 has gamma1, gamma2 but no gamma). |
Title: Re: what is the spectre format of mos transistors Post by zhonghan on Mar 20th, 2006, 7:36am Thank you , I have resolved this issue. you are right , I just copy the "vth0 " from a bsim3v3 model. By the way ,do you know the simple way to calculate the Ro of transistors with a bsim3v3 model? |
Title: Re: what is the spectre format of mos transistors Post by Geoffrey_Coram on Mar 22nd, 2006, 9:18am There's not an easy way directly from the parameters, but I think you get it from the slope of the Id/Vd curve (or 1/Gds for a Vd sweep). |
Title: Re: what is the spectre format of mos transistors Post by zhonghan on Mar 24th, 2006, 11:07pm I know the 1/ro is equal to the slope of the Id/Vd curse. But the ro is dependent on the operating point, in the other word dependent on the Vgs. So does it mean I should get different ro under different Vgs ? |
Title: Re: what is the spectre format of mos transistors Post by Geoffrey_Coram on Mar 27th, 2006, 3:26am Yes, you should. I suppose, if you are in saturation, then the Id/Vd curves are nearly parallel for different Vgs, so ro will not be strongly dependent on Vgs. |
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