Issue link: https://iconnect007.uberflip.com/i/1472851
18 DESIGN007 MAGAZINE I JULY 2022 Shaughnessy: So, you're looking to enable sys- tem designers who want to run analysis them- selves. What advice would you give to a recent grad who has just started using field solvers? What's the takeaway for those guys? Westerhoff: I think it's important to start with your ultimate goal. If you're trying to figure out whether your design works (and you should be), then everything else is a supporting detail. You need to know if your design passes or fails and by how much. You should therefore con- sider each element in the design in the context of system margin. Ask, "What process am I using to model the entire design? What pro- cess am I using to simulate it and assess suc- cess or failure?" When you need to use a field solver, ask, "What's the overall workflow? How will the field solver help me get my job done?" ere needs to be an established workflow that someone who's not a SI expert can follow. Shaughnessy: Bill, do you have any advice for anyone facing challenges using a field solver? Hargin: You mentioned young engineers figur- ing out what's what. As I said earlier, you need caution and experience when comparing field solver results to bench measurements. Simula- tions assume everything is defined exactly, and the real world doesn't work that way. If you're comparing to bench measurements, you need to determine the correct material proper- ties and dimensions for the as-manufactured device, and that can be difficult. If you're sim- ply putting spec data into a field solver and get- ting different results from what you measure, that's probably why. If you're new to the subject and asking about a good field solver, I cited three known good ones that correlate well enough that every- thing else should be compared to them. Finally, beware the free field solver, because we all know that you can go broke saving money. Shaughnessy: Good advice. ank you both, guys. is has been great. Westerhoff: Sure. ank you, Andy. DESIGN007 Bill Hargin is the author of The Printed Circuit Designer's Guide to... Stackups: The Design Within the Design.