What does "convergence" mean in Hspice simulation?

[letan]

What is "convergence" mean in hspice sim? I have met an error "no convergence in operating point" and "no convergence in dc curves at 1.5" when i simulate by hspice. Can you give me a solution for this problem?
Please help me.
Thanks.

 

[jilkdr]

no convergence in operating point hspice

Hope the attached document helps you.

 

[spikeyang]

hspice, no convergence in operating point

In spice, DC operating point is determined by numerical iterative method, when the difference between two adjacent computing results is within some tolerance, then it converge, and the computation stops.
I remember sometime you should add a very-big-value resistor (several Mohm) between an isolated node and Gnd to overcome the no convergence problem.

 

[Sadegh.j]

hspice operating point converge

I haven't faced this problem in Hspice, but in Orcad Pspice, when this happens, the accuracy of the simulation should be decreased and the simulation should be re run and you will get the result. Check for a window like the one attached.
Cheers