This project centers on the design of a single ended 10-bit successive approximation register analog to digital converter (SAR ADC for short) that easily interfaces to a micro-controller, such as an Arduino. With micro-controller interfacing in mind, the universal data transfer technique of SPI proved an easy way to communicate between the ADC and the micro-controller.
The ADC has a range of 1V (highest code value) to 0V (lowest code value) and operates from a single voltage rail value of 1.8V. Typical SPI clock speeds run on the order of 2MHz and with a 10-bit ADC this means a sampling speed of 200k samples per second, though the design could run at faster speeds. While this design does not provide groundbreaking circuit designs or ideas, it does provide an in-depth learning experience for sub-micron (180nm) circuit design.
Source: California Polytechnic State University
Authors: Ryan Hunt