A coil component includes a body including coil patterns and a plurality of trenches; and external electrodes electrically connected to the coil patterns. The plurality of trenches include a magnetic material, and at least one edge of a trench disposed outside of an outermost coil pattern among the coil patterns has a same shape as an outside boundary portion of the outermost coil pattern adjacent thereto.

An electronic component having a multilayer body that includes a plurality of insulating layers that are stacked on top of one another; a primary coil and a secondary coil that are arranged inside the multilayer body in a stacking direction of the multilayer body; a first ground electrode and a second ground electrode that are provided in the multilayer body and between which the primary coil and the secondary coil are interposed in the stacking direction; and a ground terminal that is connected to the first ground electrode and the second ground electrode. A capacitance is generated between the first ground electrode and the primary coil or the secondary coil and a capacitance is generated between the second ground electrode and the primary coil or the secondary coil.

A filter for both a differential mode and a common mode is provided. A filter for both a differential mode and a common mode according to an embodiment of the present invention comprises: a pair of series inductors having a plurality of coil patterns; two pairs of parallel capacitors connected to opposite ends of the pair of inductors, respectively; and a pair of series capacitors connected to the pair of inductors in parallel. Therefore, the filter can be used in both a common mode and a differential mode, and can remove noise without using an additional filter in an application having a comparatively high data processing speed.

Disclosed herein is a common mode filter that includes first and second terminal electrodes provided on the first flange part, third and fourth terminal electrodes provided on the second flange part, a first wire wound around the winding core part and having one end connected to the first terminal electrode and other end connected to the third terminal electrode, and a second wire wound around the winding core part and having one end connected to the second terminal electrode and other end connected to the fourth terminal electrode. The winding core part includes a first winding region, a second winding region, and a third winding region positioned between the first and second winding regions in the axial direction. The first and second wires are bifilar-wound in the first and second winding regions and layer-wound in the third winding region.

An ESD protection device includes a first terminal and a second terminal defining a first balanced port, a third terminal and a fourth terminal defining a second balanced port, and a ground terminal. A first coil and a third coil are provided between the first terminal and the third terminal to cancel an inductance component of a first ESD protection circuit. A second coil and a fourth coil are provided between the second terminal and the fourth terminal to cancel an inductance component of a second ESD protection circuit.

A coil portion providing a common mode choke coil and a protection element portion providing ESD protection elements are disposed so as to be aligned in a lamination direction of a component body. The ESD protection elements are composed of a ground electrode and discharge electrodes each located so as to be spaced apart from the ground electrode at a predetermined interval. Capacitor electrodes are provided so as to be opposed to the discharge electrodes thereby to form capacitors, and the capacitors and coil conductors of the common mode choke coil form an LC filter. Accordingly, noise removal characteristics are caused to have higher attenuation and a wider band than with a mere inductor.

A noise filter (10) is equipped with a plurality of conductors (20) having respective winding portions (21) and a ring-shaped core (30) which is inserted through the winding portions of the a plurality of conductors and made of a magnetic material. The ring-shaped core is composed of a pair of divisional cores (41) and (42) which are combined together by joining each pair of joining surfaces (43) and (44), located at each end, of the pair of divisional cores and. The one divisional core is straight and is inserted through the winding portions of the a plurality of conductors. The other divisional core has partition walls (45) each of which is located between adjacent ones of the a plurality of conductors, projects toward the one divisional core, and serves to form a magnetic path between the partition wall and the one divisional core.

A noise filter (10) used for a plurality of conducting members (20), the noise filter includes, a ring-shaped core (30) made from a magnetic material, the ring-shaped core is attached to the plurality of conducting members to reduce noise of currents flowing through each of the plurality of the conducting members. The ring-shaped core including: a base core (41) having a plurality of support pillar portions (42) extending outward in radial directions; and a plurality of divisional cores (45) each being placed between two of the plurality of the support pillar portions adjacent to each other in the circumferential direction, and each having two end surfaces connected to end portions of the two of the plurality of the support pillar portions.

The present disclosure provides an inductive element capable of lowering a Q-value. An inductive element includes a first cover and a second cover covering an annular core, and a first winding and a second winding wound around a region of the core, the first cover and the second cover. The first cover covers a part of an inner circumferential surface of the core, a part of an outer circumferential surface and an end surface on one end side in an axial direction. The second cover covers a part of the inner circumferential surface of the core, a part of the outer circumferential surface an end surface on the other end side in the axial direction.

Disclosed herein are printed circuit boards with at least one signal trace situated over or under a reference plane. The reference plane includes a broadband common-mode filter that comprises looping and parallel structures etched into the reference plane. The looping structure includes an even number of side arms, and the parallel structure comprises an even number of interior arms, wherein each of the side arms extends toward the parallel structure, and each of the interior arms extends toward the looping structure. The at least one signal trace is substantially parallel to the side arms and to the interior arms, and is situated between a first half of the even number of side arms and a second half of the even number of side arms and between a first half of the even number of interior arms and a second half of the even number of interior arms.