Optimization Study of Parasitic Parameters in Parallel Interleaved Windings for High-Frequency PCB Transformers

This study presents an innovative design approach using a parallel interleaved winding (PIW) structure to reduce parasitic effects in high-frequency PCB transformers. Among the solutions provided, the multi-branch parallel connection winding structure addresses high AC impedance and eddy current loss caused by the high-frequency skin effect of the conductor. The branch horizontal interleaved structure decreases the winding parasitic capacitance and suppresses the common mode current conduction path. The vertical interleaved winding structure improves the electromagnetic coupling between the primary and secondary windings, reducing the transformer's leakage inductance. The effectiveness of the proposed winding structure is supported by simulation and experimental results, which indicate reductions in parasitic capacitance by 37.20%, 43.54%, and 63.06%, and reductions in leakage inductance by 44.64%, 44.05%, and 44.79% at 1 MHz. Additionally, the output efficiency of the 45 V–5 V/20 A prototype has been increased by 2.8%, 2.0%, and 1.5% at 1.1 MHz.