Different constructions of step down voltage converters in terms of EMC

Abstract

At present, the designers of voltage converters can choose from a wide variety of custom integrated drivers operating at different principles. The authors of this paper aim to show that although the two different designs of a step-down voltage converters can achieve comparable nominal values, at least from the view of the user, due to the differences in the basic principles applied in their drivers they may exhibit different behaviour in the area of the electromagnetic compatibility. This can lead to considerable problems in design of more complex circuits these voltage converters are a part of. For the purposes of the hereby presented results, two different constructions of step-down converters have been chosen. The first one is based on a low-cost and randomly operating solution based on the driver MC 34063 while the second one employs more advanced driver marketed under the label AP 1501. Both converters were constructed and tested for the purposes of application in a power backup device for Power over the Ethernet. The nominal input voltage of both converters is 24 V while their nominal output voltage is 12 V, as used in common applications. Both converters were tested in the EMC laboratory of Tomas Bata University Zlin in order to obtain not only the static parameters, but also the information on how they can interfere with other electronic devices. Within this paper, the most interesting findings are published. © 2016, North Atlantic University Union. All rights Reserved.