I was re-reading stinius' class D amplifier post yesterday, and I became frustrated that, due to having no background in class D, the only part of his circuit I understood was the non-switching front end. The papers I have seen referenced (the Ph.D thesis of Nielsen and the Master's thesis of Kaspar Sinding Meyer) all seemed like they weren't appropriate as a tutorial introduction or would require a huge investment of time to come up to speed.
In searching around, I found an article by Bruno Putzeys that's really good - not too hard to understand yet provides lots of insight. It is called "Simple Self-Oscillating Class D Amplifier with Full Output Filter Control", and can be found here:
http://hypex.nl/docs/ucd_aes.pdf. I learned a lot from reading it, yet didn't have to spend huge amounts of time - very well written. I'd recommend anyone who wishes to learn about class D definitely check this article out.
Edit: I'm attaching a text file with a link to a couple of other papers by Kaspar Sinding Meyer. Very good stuff too.
