In Electronic Workbench I am getting the error
Output from instrument analysis
TRAN: Timestep too small; time = 0.029452, timestep = 1.25e-015: trouble with node $20:xu1
doAnalyses: timestep too small
I set the time step manually but still get the error and I do not see a node $20.
Right... e.g., add a bit of G-ohm leakage resistance to ground on high-Z nodes, add some series resistance for inductors, ditto for caps (esr) if in a series loop, etc. Mostly it's just stuff that always exists with real components in real circuits.
This is a node internally in the .subckt model, of probable, u1.
It doesn't matter what you set the minimum time step, this message means that internally the circuit isn't converging.
There are many reasons for non convergence. Check for floating nodes, and unrealistic circuit design.
Kevin Aylward snipped-for-privacy@anasoft.co.uk
node $20 should be in subcircuit xu1
Make sure you have a ground node, 0 (zero).
Make sure your circuit has realistic impedances... ideal inductors can ruin your day ;-)
...Jim Thompson
Right. Standard spice inductors have zero resistance, which means they have infinite Q. Standard spice capacitors also have zero resistance, which means they have infinite Q. These two components often occur together (all real inductors have self capacitance, and real nodes have capacitance to ground, etc.), potentially creating resonances with infinite Q. How is spice supposed to be able to deal with that? It's up to the user to create real components, by adding appropriate lossy resistances.
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