Patent ID: 11955262
Assignee: LG INNOTEK CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A power board, comprising:
a board;
a circuit portion formed on the board; and
an EMI filter configured to be electrically connected to the circuit portion,
wherein the EMI filter comprises:
an inductor comprising:
a magnetic core; and
a coil disposed on a surface of the magnetic core, and

a capacitor,

wherein the magnetic core comprises:
a first magnetic body having a toroidal shape, the first magnetic body comprising ferrite;
a second magnetic body disposed on an inner side of the first magnetic body; and
a third magnetic body disposed on an outer side of the first magnetic body,
wherein the second magnetic body is formed in multiple layers in a diameter direction of the first magnetic body on an inner circumferential surface of the first magnetic body,
wherein the third magnetic body is formed in multiple layers in the diameter direction on an outer circumferential surface of the first magnetic body,

wherein a thickness of the first magnetic body is greater than a thickness of the second magnetic body in the diameter direction,
wherein a thickness of the third magnetic body is less than the thickness of the first magnetic body in the diameter direction, and
wherein, when a frequency of a current applied to the inductor is equal to or less than a critical frequency, a relative permeability of each of the second and third magnetic bodies is higher than a relative permeability of the first magnetic body.