Comparison and analysis of core materials for high frequency (1MHz) planar transformers

Magnetic component materials gained supreme importance with the increasing trend towards designing high frequency, low profile and high power density converters. For obtaining optimum results and maximum efficiency, designers need to choose magnetic components materials very carefully so that high frequency parasitics could be handled effectively without compromising the system efficiency. This paper presents a brief overview of magnetic materials suitability for high frequency (MHz) planar transformer applications. It also presents a comparison of losses and temperature rise of planar magnetic cores made up of different magnetic materials categorized as F, P, R and L. EE core shape is used for designed transformer. The main idea is to find out which material category provides significant benefits in terms of losses and temperature rise for high frequency (MHz) planar transformer's core manufacturing. All results are based on 2D Finite Element Analysis (FEA) for 10W power level at 1MHz operating frequency. Results obtained by analysis shows that L category material possesses minimum losses at operating frequency 1MHz for power level of 10W. Results also signifies that L material is the most thermally stable material for 1MHz operation as its temperature rise is minimum among other core materials.