gm over id (gm/id) method part 2 MOSFET Characterization

[@anrabal3969]

Thank you very much Hafeez for this great tutorial about how to use gm/Id technique. Really Helpful. A simple suggestion: you can use VAR("name") in output expressions to use design variables. This way you don´t have to add a DC voltage to operate with MOS width.

[@mangeshmalgi279]

Thank you very much. You have explained the procedure very clearly. Thanks a lot.

[@ntdglobal2510]

FYI VAR("W") can be used in ID/W equation

[@franciscolauzurique6857]

Thank you very much for this video sir, it helped a lot!!!

[@Rohit-bx2vi]

thanx a lot.... tutorials are very helpful. Their is little problem with sound quality if possible please make it bit clear in next tutorials..

[@adityasoni4469]

I have some doubts related to analysis . Firstly in the formula of fT its Cgs and not Cgg but here we have taken Cgg Secondly , I performed the exact same steps as in the video but still my max fT was around 40GHz but in this video its around 25-26GHz

[@pallavisingh9973]

sir please .......also make some videos on LDO

[@dee311086]

Instead of plotting "w" as a voltage you can export the id curve to the calculator and there you can divide it with the value of "w". Then you plot this expression. after plotting, select the waveform and right click -> export to ADE L. an expression will add to ADE L . Or you can add an expression in ADE L directly e.g., (id / 4e-06)

[@priyadarsheesinha6176]

The step suggested by you will help if value of width you have kept constant, also u need to update the expression each time you update the width... Hafeez's technique is a generic one..

[@pyroBlastM]

Dear Hafeez, thanks for this. I would like to ask you a question. You use the same circuit testbench to plot all the curves. I have seen somewhere some people, when it comes to plot the gm/gds, they maintain the vgs fixed at a certain voltage above Vth and they vary Vds. Why you don't do like that? Regards.

[@hafeezkt1]

vds has less effect on gm/id when compared to vgs. For characterisation use vgs

[@pyroBlastM]

Ok. Will do that and see the differences. Regards and keep the good work. I like the way you do your tutorial and videos.

[@aswincvenu3958]

I see you have kept VDS as a constant for plotting all these graphs. May I ask, how will varying the vds affect the gm/d characteristics? What if I plot the gm/id for a vds of 1.8Volts? In a circuit different transistors have different vds right?

[@shashwatssanghavi]

Hi, Thank you for sharing. Just for info :).The command "save M0:all" did not work for cadence version 2020. I used "save *:oppoint sigtype=dev " instead for the save_op.scs script. Furthermore, the wavex and wavey are not recognised by ocean script compiler. It requires another workaround. We can perform YvsY directly in the maestro view instead of using ADE-L.

[@전영준-f1j]

Thanks for your advice ~ :)

[@arfic14]

what is the equivalent of the scs file for synopsys hspice?

[@theygroup]

Sir, can you please also calculate the gm using id and vgs (by taking derivative d(Id)/d(Vgs) ) and then compare it to gm simulated by cadence? I am getting different gm values for these two procedure. Thanks in advance.

[@aminebrahimi64]

Thanks a lot ....... I enjoy it!

[@deveshmonga708]

Sir, What is the use of VS,IS functions in calculator? Are they mandatory for including formulae with Operating point/ parameters in the ADE-L What is the difference between OP OPT OS options in the calculator

[@haoyingjjxu8215]

I cannot get all parameter plots (From time 6.55 in the video I am not getting that) , instead when I click my transistor(such named M0), it show subckt_trise_=0

[@ssalehas1939]

Its a very nicely explained tutorial. I want to know how to calculate the overall transconductance of an OTA based circuit and Gm vs Vid(differential voltage).Please can you help me. This tutorial is of a single MOS i want to calculate Gm of the complete circuit. thanx

[@pouram]

Dear Hafeez, How to plot Maximum available gain vs frequency, ft vs ID/W, NF vs ID/W, fmax vs ID/W curves for a given circuit in cadence?

[@aiswaryajoy2212]

Hi, Can you show how to do configuration of nmos and pmos in weak inversion region?

[@Anil13154]

Hi.. when I am trying to incorporae the .scs file, its not showing any characteristics. Its same like without incorpoarating.. Where as you are getting all parameter plots (From time 6.55 in the video I am not getting that)

[@hafeezkt1]

please make sure your mosfet name is same in .scs file and in schematic

[@Anil13154]

Yes it is the same... I have verified also, but I am unable to sort out the problem Thanks

[@diegodeotti]

Try to write M0.m1 instead of M0 only...

[@amarnathbr3420]

Run the simulation once again after adding the simulation file and then check

[@aiswaryajoy2212]

it shows id signal is unbounded while plotting gm/id vs id/(w/l) graph

[@leejohannes]

ic617... save M0:all... no effect... parametric analysis to ... anyone have better solution?

[@shashwatssanghavi]

used "save *:oppoint sigtype=dev " instead for the save_op.scs script

[@ravuruvasudevareddy3347]

@@shashwatssanghavi can u suggest, how to plot Id/width in explorer for FinFET...When i try to do it is throwing netl err even after declaring the width as parametric variable...

[@vicarz1777]

Could someone help me understand why it assigned a value of W = 5u

[@priyadarsheesinha6176]

Thanks for the detailed procedure... @hafeez KT But as you said during the lectures, you will be explaining the purpose of each of the plots for gm/Id technique

[@4NM20EC03GYANAPPADALAVAI]

sir please upload the ocean script to plot gm and id in cadence

[@NaaJeevitham500]

fT=gm/(2*pi*Cgs), can we also Cgg instead of Cgs?

[@petersords6435]

I was wondering about this too...

[@santoshkumargangala2971]

cgg=cgs+cgd in saturation cgd=Cov (very little ) we can assume cgg=cgs

[@atiqj1986]

Hi sir, please explain gm/id technique using any simple amplifier.

[@danielsapir1613]

Hi Atiq, I've followed Hafeez video series and upload an example of my own - kzbin.info/www/bejne/i4bMnIGDdqmAoKM