Analysis and Comparison of High Frequency Micro-Transformers With Different Winding Arrangements

In this work, two racetrack-shaped micro-transformers with different winding arrangements, i.e., two-layer separated windings and two-layer interleaved windings, were fabricated and compared. Based on the parameters of a novel equivalent circuit, which were extracted from measurements, some established figures of merit were employed to analyze the electrical performance of these micro-transformers. It is shown that the interleaved windings result in less winding losses and increased coupling factor, but at the price of decreased quality factor and increased inter-winding stray capacitances and stray conductances, which may deteriorate common-mode surge performance.