Simulation collapse

Simulation collapse. Qspice is acting strange.

mmmm.qsch (1.3 KB)


Yes, this seems strange!
On my PC, the simulation stopped with a “time step too small” error after successfully calculating the initial bias point using “source stepping”. So, I think the plot shows the initial bias point, not the results of the transient simulation.

The simulation worked when I used “uic” and turned off the “Fast math” setting, but it took 1785.84 seconds on my PC.

@bordodynov ,

I’m no expert in analog sims. However I’ve noticed when I implement ideal Inductors (no series R or parallel C) or ideal Capacitors (no series or parallel R or series L) AND my switching of the current path has no perceivable rise/fall time, I tend to get a ‘ringing’ effect (much like you are seeing) that sometimes gives me the same “timestep too small” error.

The fact is that the LTspice program was able to calculate the circuit, but Qspice was not! I know the influence of parasitic parameters - I have a lot of experience. I added the parameter Rser=1m, which is the same as the default in LTspice, but it didn’t help!

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