1. NL is not a Spice!

First of all, NL is not a Spice. Not only because the algorithm is different. In fact, the whole idea and purpose of NL is different.

1.1 What's the problem with Spice simulators? All Spice based simulators are designed for accurate simulation of schematics with real components, or at least what they think are real components. There are hundreds of libraries, thousands of component models, and an intention is: draw schematic with real parts, start simulation, and immediately see how your "real" prototype would work. This is definitely a very important step of the design process: it saves a lot of money, resources, and time.

Unfortunately, there are a lot of problems with Spice simulators: and don't trust anybody who says there are not. You may get used to it, you may learn how to avoid those problems, but they always exist.

The main problem is that when you enter a real schematic and try to simulate it, very often it does not work, or gives you a wrong result. Ok, ok: sometimes it does not work. But for some people: often; for me: very often; and I know people for whom it never works at first run. And for some types of schematics - 100% never works. Then you have to do a "magic": tweaking component values, simulation parameters, usually without understanding what you are doing, just to make it work. And when you see a wrong result, how do you know, is it a schematic problem, or Spice problem? Without experience, you don't. When you change some "tolerance" parameters and see different results, how can you trust those results at all? This is funny: you have to know what a correct result is in order to trust simulation results!

1.2 You still need Spice! Despite all those scary things, you still need Spice: when you have your schematic working as expected, Spice is a very good tool to do accurate analysis with parts variation, in required temperature range, etc. The question is: how to make your schematic work in Spice without doing much "magic"? How to get results you would trust? How to make Spice simulation stage of a project very efficient? This is exactly what NL was designed for.

to be continued...