Runo's Power Design

Resonance converters is a special group of SMPS converters which distinguish themselves by a potentially high efficiency and low emission of electrical noise.

Resonance converters form a huge group of topologies, however only a few of them have merits that compensate for their unattractive properties. Among resonance converters there is to-day an increasing interest in the so-called LLC and LCC half bridge converters, and new control ICs for these converter types are emerging regularly.

In common to all resonance converters it appears that they are extremely difficult to comprehend and optimise. Simple linear relations - as in other topologies - do not exist. Until now the only known design tools are approximate mathematical methods, which must even be considered quite difficult to use by most SMPS designers.

During the recent years I have succeeded in creating fast and exact mathematical tools for analysis of the LLC and the LCC converters. These tools have been an invaluable help in my design of resonance converters lately. Without a tool like that you broadly speaking grope in the dark.

As a supplement to the LLC analysis tool I have written this LLC-guide, which clearly illustrates the difficulties when trying to comprehend these converter types.
See also my article LLC and LCC resonance converters.

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