how to plot gm/id vs id in cadence?

Status
Not open for further replies.

chichi

Junior Member level 3
Joined
Aug 20, 2009
Messages
30
Helped
10
Reputation
20
Reaction score
10
Trophy points
1,288
Location
Germany
Activity points
1,512
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
 
Reactions: pcca

    P

    pcca

    Points: 2
    Helpful Answer Positive Rating
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

JoannesPaulus said:
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!
Click to expand...

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

JoannesPaulus said:
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!
Click to expand...

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
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…