How to find the right power supply: Page 4 of 4

March 09, 2018 // By René Koch, Tobias Herrmann
In a networked world, connectivity is increasing at an unprecedented rate. This often leads to faults caused by concatenations and ground loops. Power supplies in particular are affected. Again, the increasing demands on efficiency lead to higher electromagnetic emissions. This means that the filter components take up more space. It is therefore important to find the best compromise for each application.

The basic concept, on the other hand, ensures greater efficiency and lower electromagnetic emissions. For example, design at a cost comparable to that of standard flyback converters could result in an improvement of 10 dB in electromagnetic emissions or a 5 % increase in efficiency, making this concept ideal for higher-value applications.

Fig. 3: A standard 60W flyback converter for desktop use (top)
and a 60W Chibi LLC wall-mount converter (bottom).
Photo: Finepower

One of the benefits of reduced electromagnetic emissions is that the ChiBi converters can be designed without a Y-capacitor. Y-capacitors are usually used to reduce common-mode emissions by placing such a capacitor between the primary and secondary side. This usually results in a leakage current that can disturb capacitive touch panels or cause a line frequency noise (humming) in audio applications.

Tab 2: Comparison of efficiency and electromagnetic emissions
of standard flyback and Chibi converters

About the authors:

René Koch is CTO, Leader Electronics, Inc.

Tobias Herrmann is Field Application Engineer, Finepower

Design category: