Coupled inductor using near-field coupling in multi-phase VRM applications

As the power density of power module increases, the components have to be placed more and more closely and the near field coupling will become more obvious. An integrated coupling inductors scheme had been introduced by utilizing their near field coupling effects among inductors for multi-phase VRM application. Some considerations were taken such as component distance, height, air gap layout and partial magnetic path. Moreover, the near-field coupling concept was extended to general applications with multiphase topology and coupling structures of ladder and cluster type had also been proposed. Finally, experiment had been carried out for verification.