A Proprietary ZVS-Based Approach Delivers High Efficiencies at Light Load With Half the Components of Conventional Designs

The ac–dc power supply units providing isolated, regulated outputs operating above 100 W typically require some form of input active power factor correction (PFC)
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. To achieve this, a popular solution is to combine a boost PFC input stage with an “LLC” converter which isolates and controls the dc output voltage. However, a new, innovative single-stage technique for delivering regulated ac–dc power with a high input power factor offers the promise of high efficiency from no-load to full-load, while halving the number of active devices (MOSFETs) when compared to the traditional approach.