On Fri, Apr 4, 2025 at 09:03 AM, <siddhugoad@...> wrote:
I am trying to build 6T SRAM using 20nm but when i run the simulation i am having the errors saying parameter level = 72 and also other bunch of errors.
LTspice does not support "LEVEL=72" MOSFET models.? If those are the only models you have for your 20 nm devices, then you will need to use another SPICE program with it.? Probably that is HSPICE.
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LTspice accepts (among others) LEVEL=9, 14, 49, 54, and 73, but not 72.? You can find the LEVEL number by carefully examining the .MODEL statements.
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If I remember correctly, other users in this group may have used 45 nm and 20 nm models previously with LTspice, so models might exist for your devices that can be used with LTspice.? Even so, caution is called for because some of those model types are very uncommon and there are things that may not work properly, even if you get them working.? In the meantime, abandon any hope of using your LEVEL=72 models with LTspice.? It simply will not work.
my 180nm file ran properly but when i tried for 20nm it's not working although i changed W/L ratio from L=0.18 ,W= 0.64 to L= 0.02 to W= 0.3.??
Those are extraordinary incorrect W and L values!? Who would make a MOSFET that is 0.18 meters by 0.64 meters!? ?Surely those must be incorrect.? Did you forget to add the units?? (Probably missing the "u" unit multiplier.)
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Now there is a catch to what I just said.? There is a SPICE program that accepts values such as those, because it allows non-MKS units (.OPTIONS SCALM=<val>) - which IMO is a Really Bad Idea.? Anyway, if you have models that were made for that SPICE program, it would be unwise to try to use those models with any SPICE program other than the one they were made for.
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What should i do ?
I? suggest that you consider purchasing that SPICE program and using it for these simulations, and don't try to run them in LTspice nor any other SPICE program besides the one they were made for.? Those models are much too program-specific.? Note it will cost you dearly to buy that program.? That is life.? Maybe your employer already has that program.? Do not consider stealing it or getting a free "hack" of that program (HSPICE).? It is not legal.
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Andy
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