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How to sweep Threshold Voltage using .pm model file?

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npsnpsnps

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I want to check the output voltage of a block made up of pMOS and nMOS for different threshold voltages. I am using .pm file as the model file. pMOS and nMOS are used from analoglib (nmos and pmos). Can someone help if I can specify an array in the .pm file for vth parameter? Or what is the way of sweeping the Vth when the model file is .pm
 

You can't (aren't allowed to) sweep the Threshold Voltage (vth) in a model file of a certain technology: it's fixed by the technological process, which you can't alter of course.
 

You can't (aren't allowed to) sweep the Threshold Voltage (vth) in a model file of a certain technology: it's fixed by the technological process, which you can't alter of course.

Yes. You are right. But I am working on Aging. So to check my Aging behaviour, do I have to request another model from foundry with changed Vth values ?

What is the coding used in .pm file ?
 

Seems like .alter or .modif ought to be able to touch one
FET's model params, but I know nothing about ".pm" (like
specifically, what's different about it than a .lib, .inc or
flat .model statement in a netlist?).

And why not change the external .pm modeling, to one
of those forms? Can you get a model params printout in
your .out file that might be turned into a .model card?
 

I want to check the output voltage of a block made up of pMOS and nMOS for different threshold voltages. I am using .pm file as the model file. pMOS and nMOS are used from analoglib (nmos and pmos). Can someone help if I can specify an array in the .pm file for vth parameter? Or what is the way of sweeping the Vth when the model file is .pm

that doesn't make sense. what you can do is instantiate low vt, standard vt, and high vt and run 3 simulations.
 

Yes. You are right. But I am working on Aging. So to check my Aging behaviour, do I have to request another model from foundry with changed Vth values ?

What is the coding used in .pm file ?

Are you developing a new tool/feature for some aging simulations?
If not, for perform aging simulations you need to have a following things:
1. reliability tool (mosra, bert, relxpert or latest version of specte/eldo/hspice supporting aging)
2. foundry models supporting one of the mentioned reliability tool.

The general flow is to perform at least two simulations - with fresh netlist and with aged one. The aged netlist is prepared during fresh simulation to identify which transistors will degraded by which aging mechanism (and calculate a proper values of a parameters for an aging models).
 

I am using .pm file as the model file.
.........................................................
Can someone help if I can specify an array in the .pm file for vth parameter?
Or what is the way of sweeping the Vth when the model file is .pm
Show us followings.
Simulator's Name and its Version.
MOS Model you use, e.g. level-3, bsim3, bsim5, etc.
 

Hello all,

I found a different way. Instead of changing the .pm file, i can add a voltage source to the base of MOSFET and sweep the voltage source ? this would work ?
 

Hello. This method works fine but if I add a voltage source to the gate of MOS, it alters the netlist. I found somewhere that using Subcircuit which has parametric dependent Vdc inside, the netlist is not altered. Anyone know what a subcircuit is and how to create it.
 

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