Transformer Design for Isolated Switching Converters Based on Geometric Form Factors of Magnetic Cores

This paper discusses issues related to the transformer design for switch-mode power supplies based on the use of geometric form factors (GFFs) of magnetic cores. It is shown that GFFs allow a straightforward and reliable transformer design complying with loss and size constraints. It is also proved that inherent assumptions underlying the application of previous design methods based on some geometric constants can be penalizing if the effects of specific combinations of GFFs of magnetic cores are not properly considered. Examples regarding the design of transformers for forward converters are presented and discussed.