| 摘要 |
PROBLEM TO BE SOLVED: To provide a ferrite core for noise filter that can be made compact and is superior in characteristics, and whose manufacturing cost can be reduced. SOLUTION: A ferrite core 1 for noise filter has an initial permeability (μi) of 100-1,000 at 100 kHz, and the rate of increase of the frequency rate of impedance, Δlog|Z|/Δlogf (where |Z|: absolute value of impedance (units of Ω); f: frequency (Hz for unit)) in a frequency area of 100 kHz to 10 MHz, is set to 0.8 or larger, so that the frequency increasing rate of impedance, Δlog|Z|/Δlogf in a frequency area of 100 MHz to 1 GHz, is set to 0.10 or larger. |
