open-source-silicon.dev

image.png

Hello All,
I was trying to make a PTAT current generator block using sky130A in the iic-osic-tools docker environment. I am using a high sheet resistance poly resistor whose sheet resistance has a +-15% variation across process corners. However in my sims i see the resistance value hardly changing. Is it a modelling error or I am missing something?

I am including the model libraries as ".lib /foss/pdks/sky130A/libs.tech/ngspice/sky130.lib.spice ss"

Well, got the answer; my understanding was that ff, ss, sf, fs, tt are the exhaustive set of corners but it isnt

Theses are just for transistors AFAIK. There are corners for other stuff too and then the mc/mm ones for monte carlo and mismatch.

yup, had a dig at the sky130.lib.spice file and discovered it. Created additional corners for my own convenience