An ARM-based sequential sampling oscilloscope

Abstract

Sequential equivalent-time sampling allows a system to acquire repetitious waveforms with frequencies beyond the Nyquist rate. This thesis documents the prototype of a digital ARM-based sequential sampling oscilloscope with peripheral hardware and software. Discussed are the designs and obstacles of various analog circuits and signal processing methods. By means of sequential sampling, alongside analog and digital signal processing techniques, we are able to utilize a 3MSPS ADC for a capture rate of 24MSPS. For sinusoids between 6-12MHz, waveforms acquired display at least 10dB of SNR improvement for unfiltered signals and at least 60dB of SNR improvement for aggressively filtered signals.