Expression of High Frequency-Losses in Mn-Zn Ferrite

This paper gives a numerical expression for power losses at high frequencies (100 kHz to 2 MHz) in Mn-Zn ferrites, which are used as the core materials of transformers and inductors for switching power supplies. The power losses of some commercial ferrites were measured, and a new type of empirical formula was derived to express the power loss as a function of frequency and magnetic flux density. The calculated results agree well with measurements. The formula will prove useful in the design of compact and efficient magnetic components.