Performance characteristics and output coupling techniques in multi-output resonant converters

The authors present an approach to the analysis and design of multi-output resonant converters. The multi-output converter topologies can be classified on the basis of whether the multiple outputs are coupled to the resonant circuit via a single multi-winding transformer or via several two-winding transformers. In the first category, the cross regulation depends mostly on the leakage inductances of the transformer. In the other category, the cross regulation can be made independent of the transformer leakage inductances. This category offers new approaches in the converter design. As an example of the analytical technique, the state-plane analysis and the performance characteristics of a two-output half-bridge 2nd order converter with two transformers are presented. The theoretical results are verified by circuit simulation