EMI noise prediction for electronic ballasts

The design of EMI-filters for converter systems is usually based on measurements with a prototype in the final stages of the design process. Predicting the conducted electromagnetic (EM) noise spectrum of a converter by simulation in an early stage has the potential to save time/cost and to investigate different noise reduction methods, which could e.g. influence the layout or the design of the control IC. Therefore, the main sources of conducted differential mode (DM) and common mode (CM) noise of electronic ballasts are identified in this paper. For each source, the noise spectrum is calculated and a noise propagation model is presented. There, also the influence of the LISN and the test receiver is included. Based on the presented models noise spectrums are calculated and validated by measurements.