A recent question asked on the Digilent Forum was about how to measure the Total Harmonic Distortion (THD) in audio signals with the Analog Discovery 3. Let’s clarify the options.
The Question:
The Answer:
A Simple Scope Can Go A Long Way.
Network Analyzer: Built for analyzing the frequency response of circuit networks, the Network Analyzer instrument in the free WaveForms software can plot THD while it performs sweeps. In the Network Analyzer’s Magnitude settings box, go into the “Spectrum” dropdown and make sure that spectrum analysis is enabled and that the “THD” box is checked.
Scope FFT: If you need to use your own input signal, the Network Analyzer might not be an option. Fear not, the Scope instrument has options for frequency analysis too. While the Scope’s FFT window doesn’t directly measure THD, manual calculations are possible (see this video: Measuring Total Harmonic Distortion THD using an FFT on an oscilloscope)
View Forum Thread: https://forum.digilent.com/topic/31034-misure-thd-with-analog-discovery-3/
Learn more about Waveforms here.
