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Simulators >> Circuit Simulators >> Cgg vs Vgs for MOSFETs
https://designers-guide.org/forum/YaBB.pl?num=1112723856

Message started by cricket_fan on Apr 5^th, 2005, 10:57am

Title: Cgg vs Vgs for MOSFETs
Post by cricket_fan on Apr 5^th, 2005, 10:57am

Hi

I am trying to look at the Cgg of a mosfet device. I am using Cadence dsign environment for this.

When I do a dc sweep of the gate under various drain biases (linear/saturation) , how can I plot Cgg against Vgs using the calculator.

I had done this before but using a raw netlist file and running spectre standalone (without Cadence) and it was possible to obtain Cgg as an output parameter.

Any pointers/suggestions would be helpful.

thanks
MMN

Title: Re: Cgg vs Vgs for MOSFETs
Post by Andrew Beckett on Apr 7^th, 2005, 1:25pm

This has been answered several times before in this forum, albeit in a slightly different form.

http://www.designers-guide.org/Forum/?board=rfdesign;action=display;num=1085050640;start=5#5

which in turn has a reference to another similar answer.

Regards,

Andrew.

Title: Re: Cgg vs Vgs for MOSFETs
Post by nus_lin on Apr 8^th, 2005, 12:46am

poor andrew, you have to answer the same question again and again, ;D

hi, do you know the meaning of cgg, cgd, cgs, csg in the bsim3 model? why they are sometimes negative? if i want to manually find out the capacitance at one node, what should i do from the op point?

Title: Re: Cgg vs Vgs for MOSFETs
Post by Andrew Beckett on Apr 8^th, 2005, 6:13am

OK, prepare to be sympathetic to me again. This one I've answered at least twice:

http://www.designers-guide.org/Forum/?board=analog_design;action=display;num=1087411058;start=1#1
http://www.designers-guide.org/Forum/?board=semi;action=display;num=1053460340;start=1#1

See that little magnifying glass, with Search written next to it at the top of the page... well, guess what it's for?

(a search for "bsim3v3 negative capacitor" found the two links above).

Andrew.

Title: Re: Cgg vs Vgs for MOSFETs
Post by cricket_fan on Apr 8^th, 2005, 12:29pm

Ignore previous message I found out how to get all parms. of individual MOS instances.

thanks