Access at:
https://liquidinstruments.com/frequency-domain-control-the-ultimate-guide-to-control-loops/
Application note details
- Title: Frequency-domain control: The ultimate guide to feedback and control loops
- Date published: January 3, 2025
Access at:
https://liquidinstruments.com/frequency-domain-control-the-ultimate-guide-to-control-loops/
Application note details
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In this application note, we discuss how to acquire and analyze signals above the Nyquist frequency on Moku:Delta, making use of the full analog frontend of the device. We review the concepts of the Nyquist-Shannon sampling theorem and the constraints it places on digital sampling. We explain the advantages of this method and important considerations for making use of it. We illustrate several examples using the Moku:Delta 6 GHz mode to make measurements above the first Nyquist zone.
Featuring: Moku:Delta, Spectrum Analyzer
In this application note, we demonstrate how to perform both traditional (invasive) and non-invasive stability measurements (NISM) on a voltage regulator (VRTS 1.5) using the Frequency Response Analyzer on Moku:Pro . By comparing the two methods, we show that the NISM technique provides phase margin estimates that closely match those from traditional loop - breaking measurements, while eliminating the need to physically interrupt the circuit . These results confirm that NISM is a reliable and efficient tool for assessing control loop stability, offering engineers a faster and more practical alternative to conventional techniques.
Featuring: Moku:Pro, Frequency Response Analyzer
Cross-correlation a useful technique in signal processing, essentially comparing the similarity of two signals. We discuss its use in signal processing applications. Finally, we present the concept of cross-power spectral density, which is the equivalent of cross correlation in the frequency domain, using the Moku Oscilloscope and Spectrum Analyzer to illustrate several examples.
Featuring: Spectrum Analyzer, Moku:Delta