8.2.2.2.6 Winding and Magnetic Core Materials

Not only by the control of AC flux density (ΔB) with L_M and N_P design, the core loss of the transformer can also be significantly reduced by a proper selection of the magnetic core material. For a converter operating at 200 kHz to 400 kHz of switching frequencies (at full load condition), core materials such as 3F36 from Ferroxcube and N49 from TDK exhibit low core loss density in the frequency range. Litz wires are recommended for both primary and secondary windings, in order to reduce the AC winding loss caused by the proximity effect and the skin effect of the transformer windings.