摘要 |
A choke coil includes an embedded core having a first core and a second core embedded within the first core, and a pair of coils wound around the first core and the second core. The first core and the second core are made of different materials which have different initial permeability (mu<SUB>i</SUB>). The second core has a gap filled with the same material as the first core. For example, the first core includes Fe-base magnetic metal or a Fe-based magnetic alloy for eliminating differential mode noise, and the second core includes ferrite for eliminating common mode noise. Thus, the choke coil can eliminate both common mode noise and differential mode noise at the same time and reduce the whole volume of the choke coil.
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