Trace Impedance in Switch-Mode Power Converters

Some of the components used in switch-mode power converters, such as inductors and transformers, may cause substantial power loss when switching frequency is largely increased. If extra heat dissipation or decreased efficiency is not acceptable, one needs to search for a method of reducing power loss. With higher switching frequency, inductors and transformers are commonly implemented with traces on the PCB layout. Planar PCB traces are not free from skin and proximity effects. The influence of these two effects on trace impedance is determined by the layout geometry. In this paper, we discuss the dependence of AC resistance on current frequency while varying the trace geometry. Our results may assist in design of new inductive component geometries to gain better performance and mitigate power loss.