
The permeability of MnZn ferrite can reach up to 5000, but it may start to decrease at a frequency of 20kHz. At a frequency of 30MHz, its permeability has already decreased significantly, resulting in a relatively low impedance. NiZn ferrite has a low initial permeability (<1000µ), but it can maintain its permeability at very high frequencies (>100MHz). At 30MHz, it can maintain a certain level of permeability, so its impedance is relatively high. However, the specific impedance difference is difficult to quantify accurately. Generally, at 30MHz, the impedance of NiZn ferrite common mode inductors may be several times to tens of times higher than that of MnZn ferrite common mode inductors.