New Ferrites and Distributed Air Gaps for WBG Semis
TDK Corporation has announced the new MnZn-based PC200 ferrite material, which is characterized by low losses at high frequencies. It was developed specifically for power supplies and frequency converters that operate with fast-switching wide bandgap (WBG) power semiconductors such as GaN.
The new material is optimized for a frequency range from 700kHz to 4MHz. Its maximum transmissible power is reached at a switching frequency of 1.8MHz to 2MHz and an operating temperature of 100 °C. The ferrite material’s Curie temperature is in excess of 250 °C.
The PC200 ferrite material is particularly suitable for transformers based on ring core or planar topologies. The new material is available in ER, EFD, ELP, EQ, I and RM cores. The outstanding properties of this material will enable considerably more compact power supplies to be designed in future.
At the same time, its efficiency is improved due to the low losses of the ferrite material, which is why the use of PC200 contributes to significantly greater energy savings.
In addition, TDK has introduced the first ferrite cores that enable additional copper losses to be reduced by up to 70 percent. The core design using distributed air gaps permits higher operating frequencies and smaller inductive components to be used in power supply systems.
By reducing electromagnetic emissions, the additional copper losses at high frequencies are also reduced. Thanks to the identical distributed gaps in the center posts, the magnetic field emission to the environment is effectively prevented.
Ferrite cores are available with distributed air gaps in E, EQ, ER, ETD, PM and PQ core designs, and with all EPCOS power materials. Solutions with three identical air gaps offer the best price/performance ratio for applications, in which 2 or 3 times the switching frequency is used in comparison with the original frequency.
Apart from standard solutions, a customer-specific number of air gaps can also be implemented. The main applications for the new cores are in storage chokes and transformers in switch-mode power supplies and inverters.