soft ferrite cores are still the best choice for switching power supply

In order to meet the requirements of switching power supply to improve efficiency and reduce size and weight, a transformer core with high magnetic flux density and high frequency and low loss is required. Although there is competition for high-performance amorphous soft magnetic alloys, soft ferrite materials are still the best choice in terms of cost performance; especially in the high frequency range of 100kHz to 1MHz, new low loss high frequency power Ferrite materials have their unique advantages. In order to make maximum use of the magnetic core, the soft magnetic ferrite material under high power operating conditions should have the following main magnetic characteristics in the high temperature working range (eg 80~100 °C):

1. High saturation flux density or high amplitude permeability. This allows the transformer core to have a large flux offset at the specified frequency, which results in a reduced number of turns; this also facilitates the high frequency application of the ferrite since the cutoff frequency is proportional to the saturation flux density.

2. There is a low total core loss in the operating frequency range. At a given temperature rise, low core losses will allow for high pass power.