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.

A common mode filter includes a body including a filter portion and an electrostatic protection portion, first to fourth external electrodes disposed on an external surface of the body, a ground electrode disposed on the external surface of the body, a first coil included in the filter portion and electrically connected to the first and second external electrodes, and a second coil included in the filter portion and electrically connected to the third and fourth external electrodes. The electrostatic protection portion includes discharge electrodes electrically connected to at least one of the first to fourth external electrodes and the ground electrode, a discharge part including conductive particles, a first organic-inorganic composite insulating layer disposed on the discharge electrodes and the discharge part, a magnetic cover layer disposed on the first organic-inorganic composite insulating layer, and a first inorganic insulating layer.

A common-mode choke coil includes a first filter unit and a second filter unit, each of which serves as a common-mode filter unit and is formed by arranging a primary coil and a secondary coil in a stacking direction. Of the first filter unit and the second filter unit, the first filter unit has a resonant frequency different from that of the second filter unit, and the line length is different between the primary coil and the secondary coil.

A conductive path with noise filter that enables an effective reduction in a surge noise in a specific frequency band is provided. A conductive path with noise filter includes conductive path main bodies, insulating layers that respectively surround the conductive path main bodies, conductive layers that are respectively provided to correspond to the conductive path main bodies with the insulating layers being sandwiched between the conductive layers and the conductive path main bodies and that respectively form capacitors in combination with the conductive path main bodies, and inductors connected to the conductive layers.

Disclosed herein is a common mode filter that includes a winding core part and first and second wires wound in a same direction around the winding core part. The first and second wires constitute a first winding block on one endmost side in an axial direction of the winding core part, a second winding block on other endmost side in the axial direction of the winding core part, and a third winding block positioned between the first and second winding blocks. The second winding block is a winding block at an odd-numbered position counted from the first winding block. The first and second wires cross each other in an area between the first and third winding blocks and in an area between the second and third winding blocks.

A circuit module includes a wiring board on which are provided a ground plane, a signal line, and a conductive pattern for connection to an outer conductor of a coaxial cable including an inner conductor and the outer conductor. A common-mode choke coil is mounted on the wiring board such that one of coils of the common-mode choke coil connects the ground plane and the conductive pattern and that the other coil is inserted in the signal line. A communication element is mounted on the wiring board and includes a first signal terminal and a second signal terminal. The first signal terminal is connected to the common-mode choke coil via the signal line, and the second signal terminal is connected to the ground plane. A first capacitor is inserted in series in the signal line between the common-mode choke coil and the first signal terminal.

An electronic component includes an element body, an external electrode, and a resin film having electrical insulation properties. The element body includes a principal surface and a side surface adjacent to the principal surface. The external electrode includes a first electrode portion disposed on the principal surface and a second electrode portion disposed on the side surface. The resin film is disposed on the principal surface and is in contact with the principal surface. Each of the first electrode portion and the second electrode portion includes a conductive resin layer disposed on the element body. A conductive resin layer included in the first electrode portion is disposed on the resin film and is in contact with the resin film.

A filter component assembly kit includes a bobbin that is configured with first and second members and a core that is in a quadrangular frame shape. When the first member is assembled with the second member, a through hole is formed in the bobbin. The through hole extends in a first direction. The core is configured with first and second extension bars. The first and second extension bars extend in parallel in the first direction. When the first extension bar is disposed in the through hole of the bobbin, rotation of the core around the first extension bar is prevented. First allowance of the first extension bar in a second direction, which is perpendicular to the first direction, in the through hole is larger than second allowance of the first extension bar in a third direction, which is perpendicular to the first and second directions, in the through hole.

Provided is a filter device to be connected between an AC power source (1) and a PWM converter (2), which includes a first AC reactor (3), a second AC reactor (4) that is connected between the PWM converter (2) and the first AC reactor (3), a filter capacitor (5) whose one end is connected to a connecting portion (9) between the first AC reactor (3) and the second AC reactor (4), and a housing (15) having a cooling air inlet (16) and a cooling air outlet (17) and containing the first AC reactor (3) and the second AC reactor (4), wherein the first AC reactor (3) is disposed upwind of the second AC reactor (4).

A common mode inductor apparatus includes a magnetic core, a first coil winding and a second coil winding. The magnetic core has a first winding zone and a second winding zone. The first coil winding is wound in three winding areas within the first winding zone, wherein two neighboring winding areas within the first winding zone are separated by a gap. The second coil winding is wound in three winding areas within the second winding zone, wherein two neighboring winding areas within the second winding zone are separated by a gap.