SCDA058 September 2025 TMUX1575 , TMUX4827 , TMUX7612 , TS5A22362 , TS5A22364
Total Harmonic Distortion (THD) and Total Harmonic Distortion plus Noise (THD + N) are key performance metrics for evaluating signal fidelity in analog systems. In applications such as audio, test and measurement and biomedical instrumentation, even minor distortions can significantly degrade performance and reliability. This application note explains the mathematical basis of THD and THD+N, outlines standard test setups for multiplexer (mux) characterization and highlights the impact of On-Resistance (RON) and RON-flatness on distortion performance. Practical examples are provided to illustrate how low-THD multiplexers, such as the TMUX4827 and TMUX7612, enhance performance in audio switching, precision measurement, programmable gain amplification loops and biomedical sensing. By Understanding THD behavior in mux devices and selecting components with optimized RON characteristics, engineers can make sure accurate signal reproduction and robust system performance across diverse applications.