This tutorial goes along with an upcoming Circuit Cellar article of mine on construction of a 5V / 2A USB power supply I built for my car. Why not simply purchase a cheap cigarette-lighter USB power supply? Well, two reasons. First, I needed an isolated power supply, something to keep the car’s power system hum and buzz from the audio when I used the line-in on the car’s radio. Second, it’s always more fun to build something yourself and learn something in the process. So go read the CC article!
For this tutorial, I wanted to outline some of the LTSpice usage in more detail than was possible to cover in the Circuit Cellar article. There are other LTSpice tutorials out there, like this one, but I wanted to do something a bit more specific for someone trying to follow along my 5V/2A isolated switching power supply design. The purpose here isn’t to walk you through the details of the specific switching power supply design I did (that’s more the Circuit Cellar article); here I more wanted to present an overview of how to use LTSpice for switching design so you can design your own circuit.