High frequency bus converter with integrated matrix transformers for CPU and telecommunications applications

The trend in intermediate bus architectures is increasing output power demands and higher operating frequencies. Improved topologies and semiconductors can allow for lower loss at higher frequencies. A major barrier to further improvement is the transformer design. With high current levels and high frequency effects the transformers can become the major loss component in the circuit. High values of transformer leakage inductance can also greatly degrade the performance of the converter. Matrix transformers offer the ability to reduce winding loss and leakage inductance. This paper will study the use of matrix transformers for a 600-W, 12-V/50A bus converter and identify the optimal number of matrix transformers. This paper will also propose an improved integrated matrix transformer design that can decrease core loss and further improve the performance of matrix transformers.