@Jorge Marin I'm working with sky130. I ran into the same issue, and the only way I could avoid it is to use a relatively very small time step. I'm curious which order of the

gear

method did you use? and which

ngspice

version?

hello @Ahmed Reda, I'm also trapped by the small time step I use plain method = gear (any other option you would recommend?) and ngspice version 43

Just asking because I used the default

gear

method (order 2) and it didn't help. same

ngspice

version.

Some good tips: https://efabless.com/kb-articles/overcoming-spice-convergence-issues https://kenkundert.com/docs/eda+t93-paper.pdf