A comparative study of high-frequency, low-profile planar transformer technologies

A study several of available technologies used to construct low-profile, planar transformers is presented. Finite element analysis is used to determine an appropriate winding configuration with low AC resistance and leakage inductance. The advantages and disadvantages of printed circuit board (PCB), flex-circuit and stamped-copper winding technologies are evaluated. The trade-offs between electrical and mechanical properties are emphasized. It is demonstrated that the secondary winding termination resistances for these transformers constitute a large percentage of the total AC resistance of the transformer.<
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