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how to plot gm/id vs id in cadence?

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chichi

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plot gm in cadence

i am trying to plot that gm/id look up graph,i sweep the Vgs,and can plot gm ,id,gm/id,over vgs,just don't know how to plot gm/id vs id,having no idea how to make one signal as x axis,and another as y axis,can anybody answer me that?
i already read some stuff about it in this forum,but still did not get how to plot it..
 

plot log of y axis in cadence

plot your gm/id curve, then plot the id curve and then in your waveform window: axis->x axis->Plot vs. ...
click on the scroll down an select the id curve.
Done!

I hope it helps!
 
thanks, i got it ,and get the result now,really many thanks,i worked on that the whole evening...

Added after 4 minutes:

i actually plot gm and id vs vgs,using vgs as a variable,which take a long long time to run,is there any other ways,like component sweep,but whenever i do like that,i got only one gm or id value,i can't see the whole sweep process values
 

export the data as a table and plot in matlab
 

so would you please tell me how to simulate the gm in the cadence? I am using the simulator of HSpiceS。。。
 

i see ur message,u need to find out the gm id curve right?this is only a usefull table for designing OTA,u need to find gm id curve for the transistor of CMOS technology u are using.
firs ,build a simple single transistor circuit,and then set the Vgs of a transistor as a variable.and then do the parameter simulation ,after this,go to the result browse and check the gm,here u will find the gm vs vgs curve,and then check the id,u will find the id vs vgs curve.
the x axis of id vs vgs is vgs,now copy the gm vs vgs curve into it,and then go to the properties of x axis,change it to the gm ,then u will got the id vs gm curve
 
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    pcca

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i jus got to know how to plot gm/id vs vov for a fixed w and l. but i wanna know how to plot the same for various lengths? while doing parametric analysis,when i double click on x-axis to set VOV, there are many VOV s each for each length?do anyone know this..?help me.............
 

Re: plot log of y axis in cadence

plot your gm/id curve, then plot the id curve and then in your waveform window: axis->x axis->Plot vs. ...
click on the scroll down an select the id curve.
Done!

I hope it helps!

Hi JoannersPaulus,

I plotted my gm/id vs. |vds| and id vs. |vds| using parasitic sweeping. But why I cannot use what you said to YvsY them? The scroll down menu only contained its own x and y value rather than the proposed 'z' value. If I put two curves together, three options appeared but no matter I choose which one nothing happened. I am crazy now! Who can help me!

BTW, I have obtained the desired plot by matlab. But I just want to plot it on Cadence!!

Have fun!

Justin
 

Re: plot log of y axis in cadence

plot your gm/id curve, then plot the id curve and then in your waveform window: axis->x axis->Plot vs. ...
click on the scroll down an select the id curve.
Done!

I hope it helps!

I know that his post is old, but I wanted to get some help desperately. I am using Virtuoso 6.1.5 and want to do exactly what chichi above wants to do. But, I do not see the option 'x axis -> plot vs...' anywhere. I used to do this when I used cadance few years back ( and then moved to script based simulator), but can't seem to find it anymore. I am in desperate need of this - please help!

Thanks
 

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