how to simulate gm/id curve for CMOS device?

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lijulia

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id curve

thanks!
 

gm id cmos

Use MOSFET transistor modell in simulation, it has the basic equations built in. (Can't hardly imagine how to simulate without an appropriate model).
 

gmoverid

Yes, basically when you use 1st order equation, the ideal one is gm/Id = 2/Veff. However, if you use realistic model to simulate, it is far from ideal. Basically you can use SPICE to sweep the Vgs and calculate gmoverId. Then plot gmoverId vs different Vgs values and you can see that it's far from ideal cases.
For SPICE there is a parameter called gmoverId that you can use immediately. If you use SPECTRE, it will be more tricky as you need to set up .scs files in order to capture different .op points.

Hope it helps.
David.
 

how to get gm/id curve

look here:



twards the second half of the post
 
simulate being a gm

use this command in Hspice

.PROBE gm_Id=par('gmo(Mn)/I(Mn)')

B.R.
 
gmid mos

About this problem, I have a question:
For a given Id, you can got a lot of possible operating points with different Vgs and Vds.
For different operating points, the gm is not constant.
 

gm/id how to simulate for multiple l

I am posting one paper & 2 ppts on the method , i hope it will help.
 

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