Patent ID: 8723629

Claim:
A magnetic device comprising: a T-shaped magnetic core including a base and a pillar, the base having a first surface and a second surface opposite to the first surface, the pillar being located on the first surface of the base, the second surface of the base being exposed to outer environment as an outer surface of the magnetic device, the T-shaped magnetic core being made of an annealed soft magnetic metal material, a core loss P CL (mW/cm 3 ) of the T-shaped magnetic core satisfying: 0.64 ×f 0.95 ×B 2.20 ≦P CL ≦7.26 ×f 1.41 ×B m 1.08 , where f (kHz) represents a frequency of a magnetic field applied to the T-shaped magnetic core, and B m (kGauss) represents the operating magnetic flux density of the magnetic field at the frequency; a wire coil surrounding the pillar, the wire coil having two leads; and a magnetic body fully covering the pillar, any part of the base that is located above the second surface of the base, and any part of the wire coil that is located directly above the first surface of the base, wherein a permeability of the magnetic body is μ B , and wherein μ B ≧4.8, and the core loss P BL (mW/cm 3 ) of the magnetic body satisfies: 2 ×f 1.29 ×B m 2.2 ≦P BL ≦14.03 ×f 1.29 ×B m 1.08 .