# LT Spice simulation error: 'Time step too small'

Could someone get this up and running? Tried all the possibilities but it does not seem to work still.

Here I am just trying to simulate the linked circuit here .. PMP7763 design reference

• You're missing grounding on the secondary side. What are those "all the possibilities" that you tried? Jun 11 at 13:04
• According to my experience, one ground point per simulation is good enough. The secondary side not necessarily have any ground reference. Jun 11 at 13:06
• Undefined voltages tend to be one of the causes of unpredictable simulation behaviour like convergence or timestep errors. If you don't want a ground connection on the secondary side, at least connect a 1Gigohm resistor from secondary to GND. Jun 11 at 13:41
• It's a simulation; not real life - help the sim by grounding the secondary. Jun 11 at 13:43
• Can you list everything else you have tried? For example, have you tried setting .options cshunt to a non-zero value? Also, you can copy/paste the .asc file's text into a code block in your question so others can try tinkering around to try to get it to work. Jun 11 at 16:01