Benefits of multiphase Buck converters in reducing EME (Electromagnetic Emissions) Analysis and application to on-chip converters for automotive applications

Inside the car, all integrated circuits “IC” have to be optimized to survive against severe external aggressions. The noise generated by each activity inside each IC must be low enough, to not disturb the environment. As known nowadays, DC-DC converters can significantly impact the Electromagnetic Compatibility “EMC” performances, and mainly the emission ones. Unfortunately, simulation with linear models like ICEM or IBIS models [1, 2] remains very challenging for integrated analogue products due to the high number of parameters, plenty of possible applications and the extent of the frequency domain where the integrated circuit must be compliant. A paper describes an analytical approach to highlight the main contributors to the high frequency noise generated by switching activity in Buck converters [3]. This approach is here employed to evaluate Conducted Emission “CE” performance of multiphase interleaved Buck converters and to highlight benefits of increasing the number of phases in improving the emission profile.