A Simple A/D Converter Using a PLD
You can really do a lot of things with PLDs. For example, with just 26 macrocells you can implement an 8-bit A/D converter based on a sigma-delta modulator (ΣΔM) followed by a digital low-pass/conversion filter. The accuracy, resolution and complexity of this project are described in this article. An interesting aspect is that the digital filter accounts for most of the complexity.