Compared with ferrite core, nanocrystalline cores has extremely high impedance and wide effective frequency band. This makes the components smaller and saves the engineering time required to design and test other EMI countermeasures. Therefore, the nanocrystalline core is very suitable for the design of complex EMI noise scenes (high-energy noise and / or noise of multiple different frequencies). In simple scenarios where the noise energy is small or concentrated at one frequency, cheap ferrite cores are usually sufficient.