Investigation of Switching Frequency Variations and EMI Properties in Self-Oscillating Class D Amplifiers

Nielsen D, Knott A, Pfaffinger G, Andersen MAE. Investigation of Switching Frequency Variations and EMI Properties in Self-Oscillating Class D Amplifiers. In: AES Convention 127. Audio Engineering Society; 2009. Paper 7907. Available from: https://aes.org/publications/elibrary-page/?id=15102

@inproceedings{Nielsen2009_15102,
  author = {Nielsen, Dennis and Knott, Arnold and Pfaffinger, Gerhard and Andersen, Michael A. E.},
  title = {{Investigation of Switching Frequency Variations and EMI Properties in Self-Oscillating Class D Amplifiers}},
  booktitle = {AES Convention 127},
  note = {Paper 7907},
  year = {2009},
  month = oct,
  publisher = {Audio Engineering Society},
  url = {https://aes.org/publications/elibrary-page/?id=15102}
}

TY  - CPAPER
TI  - Investigation of Switching Frequency Variations and EMI Properties in Self-Oscillating Class D Amplifiers
AU  - Nielsen, Dennis
AU  - Knott, Arnold
AU  - Pfaffinger, Gerhard
AU  - Andersen, Michael A. E.
T2  - AES Convention 127
M1  - Paper 7907
PY  - 2009
DA  - 2009/10/06
UR  - https://aes.org/publications/elibrary-page/?id=15102
PB  - Audio Engineering Society
LA  - en
AB  - Class D audio amplifiers have gained significant influence in sound reproduction due to their high efficiency. One of the most commonly used control methods in these amplifiers is self-oscillation. A parameter of key interest in self-oscillating amplifiers is the switching frequency, which is known for its variation. Knowledge of switching frequency variations is of great importance with respect to electromagnetic interference (EMI). This paper will investigate, whether the switching frequency is depended on modulation index and audio reference frequency. Validation is done using simulations, and the results are compared with measurements performed on a 50 W prototype amplifier. The switching frequency is tracked through accurate spectrum measurements, and very good compliance with simulation results are observed.
ER  -