Design Considerations for Planar Magnetic Terminations

Termination losses in planar magnetics can be important in high-current, high-frequency designs. In this paper, we elucidate the loss mechanisms involved and offer simplified models for estimating their impact so that designers using planar magnetics can gauge their potential significance in a given design. The use of the model and possible loss mitigation strategies are explored in an example case study for a 20:1 planar transformer. Experimental results highlight the importance of termination effects and demonstrate the relative performance of example mitigation strategies.