How to plot the transconductance (gm) in Spectre?

[markl]

plotting gm in spectre

So I would like to plot the transconductance (gm) in specter during a dc sweep. However I can only get it to print the final value of gm.
Any ideas on how to do this?

 

[micel99]

plotting gm in spectre

I think somebody asked the similar question and got good answers from here. Please search it out.

 

[Question]

plotting gm in spectre

I think you need to use 'calculator' in Cadence to get it.

 

[Puppet1]

Re: plotting gm in spectre

plot id vs. vgs in cadence

then take the derivative of the curve

 

[huyamu]

plotting gm in spectre

Or you could use parametric analysis instead of DC sweep, and you can directly plot gm of the transistor (e.g. input pairs) versus sweep DC voltage by using calculator.

 

[markl]

Re: plotting gm in spectre

This is a solution I found on another forum... I have yet to try it out.

**broken link removed**

 

[sutapanaki]

Re: plotting gm in spectre

the same thing, but more detailed in explanation is here:

 

[Teddy]

Re: plotting gm in spectre

Run the simulation,

Open Calculator

Hit op button - little popup will (should) appear. Select on schmatic the device you are interested in and the in pulldown menu list in the pop-up select gm.
Then hit plot in calculator.

 

[chinito]

Re: plotting gm in spectre

Better yet, go with the definition of gm. Plot Id with DC sweep. Use calculator to find d(Id)/d(Vgs) and plot. always go with definition. If you need lambda to find rout, go with the definition again: lambda = (1/Id) * d(Id)/d(Vds).

 

[Aforanalog]

Re: plotting gm in spectre

hi sutapanaki,


i am using ic 4.46 of analog artist at school.i guess the "results browser" is well equipped in IC5.03.


i dont find the "psf" ,"dc-dc" stuff in my version

i would greatly appreciate it if u can give me some hint on how to do the gm plot
in the version i have .


thanks a lot for ur time