Class D Amp

Before You Continue:
I made a modular PCB version for the schematics Class D Amp Workshop - OSHWLab
I intended to merge the two projects together, but I don't think EasyEDA allows me to that very easily. The schematics from this project should match up with the PCBs in the Workshop version.Three different schematics for a Class D Amplifer (Mono Half-Bridge, Stereo Half-Bridge, and Stereo Full-Bridge). So, I will use this project page for main schematics and theoretical details only. The Workshop version will have all of the modular PCBs and a detailed BOM. 

Project Goal:
The goal of this project was to create a simple Class D amplifier using common components that can be found in a university ECE lab. This way, any student may learn more about circuits by building one themselves.

Design Limitations:
- The carrier wave is a sawtooth waveform being used instead of a pure triangle wave. Distortion occurs for bass notes at high audio volume due to a non-linear change in voltage in a sawtooth waveform.
- Connecting the output to a speakers actually causes a lot noise to feedback in to the low voltage inputs (everything before the MOSFET driver). Perhaps if optoisolaters are added between the comparator output and the MOSFET driver input, there might less distortion from the feedbacking noise.
- The fact that the audio signal has to be biased into the boundary peaks of the carrier wave also adds some inefficiency. If the carrier wave generator had an AC output (currently positive magnitude only), then no biasing would be needed for the audio signals and increase efficiency.

Theory:
I might end up posting a PowerPoint to explain how it all works once it get's approved by the university department.

Special thanks to McMaster University and Voltera for making this possible! I would not be able to get the required components and lab resources without my university. I would also not be able to prototype PCBs without the Voltera V-One PCB Printer. It's very convinient that I can prototype PCBs now without having to wait 1-2 weeks from JLCPCB for every PCB iteration. I'd also like to thank Abin Raju from Datec Coating Corporation for connecting me with Voltera.