The market requiring more efficiency in the areas of LED lighting, server farms, gate automation, battery chargers, vending machines, etc. is a widely known fact.
Besides the marketing driven requirements, many standards impose higher and higher efficiency targets.
This lead to a great revaluation of the LLC (and in some cases LCC) resonant topology in the last few years.
All the major active components manufacturers on the SMPS market have therefore developed controllers allowing the realization of high efficiency converters with low EMI emissions, with a particularly low circuit complexity.
– efficiency around 94-96% in the simplest circuit solutions, with the possibility of improvement through synchronous rectification and/or other precautions;
– using correctly designed magnetic components, the design is very quick and simplified;
– high frequency currents wave shapes are substantially sinusoidal, with a very limited harmonic content compared to other topologies;
– “ZVS” (zero voltage switching) of MOSFETs that causes a dramatic reduction of losses, reduction/elimination of the heatsink and reduction of stress and generated disturbances, which often cause the most unpredictable and hostile design problems;
– possibility of low power at light load/stand by using the “burst mode” and “PFC stop” functions implemented on many controllers;
– possibility of optimal design for continuous and temporary power even very distant from each other (e.g. our transformer with a size equal to that of a classic EF25 can arrive up to a 500-1000W peak power);