A common mode filter includes: a body including a filter portion; first and second external electrodes each including an electrode layer including conductive particles, intermetallic compound (IMC) formation particles, and a resin, and disposed on an external surface of the body; and first and second coils disposed in the filter portion, the first and second coils being connected through lead portions to the electrode layers of the first and second external electrodes, respectively. The conductive particles include a first conductive particle and a second conductive particle having a diameter smaller than that of the first conductive particle.

A power conversion device according to an embodiment of the disclosure includes: first, second, third, fourth, fifth, and sixth elements coupling, respectively, a first voltage line to a first node, a second voltage line to the first node, the first voltage line to a second node, the second voltage line to the second node, the first voltage line to a third node, and the second voltage line to the third node; a low-pass filter including two or more reactors provided in respective two or more paths of first, second, and third paths, respectively, coupling the first node and a first output terminal, coupling the second node and a second output terminal, and coupling the third node and a third output terminal, and first and second capacitors; and a control section calculating voltage differences across the respective two or more reactors to control operations of the fifth and sixth elements.

A filter apparatus, which includes a feedback active common-mode filter and a feed-forward active common-mode filter, the feedback active common-mode filter includes a common-mode noise detection component and a first filter circuit, and the feed-forward active common-mode filter includes the common-mode noise detection component and a second filter circuit, where the first filter circuit is connected between the common-mode noise detection component and the device, and performs feedback filtering on a first common-mode noise signal, to obtain a second common-mode noise signal; the common-mode noise detection component is connected between the first filter circuit and the second filter circuit, detects the second common-mode noise signal, and provides the second filter circuit with the second common-mode noise signal; and the second filter circuit is connected between an external power source and the common-mode noise detection component, and performs feed-forward filtering on the second common-mode noise signal.

A radiofrequency filter utilizing a common mode choke both as a traditional common mode choke as well as the inductance in a low pass filter. Filter topology as well as component selection is optimized for wide band operation. Common mode chokes allow differential currents to pass with little attenuation while common mode currents are effectively presented with an inductance in the common current path. This inductance is used in a low pass filter configuration to present an even higher attenuation to common mode currents. The use of multiple chokes and/or differing core materials contributes to wider band operation without pronounced resonances. The capacitance used in the low pass filter is connected in a way as to reduce its effect on the data signals while still being effective in filtering.

A common mode noise filter includes a laminated body having insulator layers therein and first and second spiral conductors provided on layer planes different from each other. The first spiral conductor includes a first spiral conductor line, a first pad provided at an outer end of the first spiral conductor line, and a second pad provided at an inner end of the first spiral conductor line. The second spiral conductor includes a second spiral conductor line, a third pad provided at an outer end of the second spiral conductor line, and a fourth pad provided at an inner end of the second spiral conductor line. The first spiral conductor line faces the second spiral conductor line. Each of the second pad and the sixth pad overlaps none of the fourth pad and the eighth pad viewing from above.

A power conversion device according to an embodiment of the disclosure includes: first, second, third, fourth, fifth, and sixth elements coupling, respectively, a first voltage line to a first node, a second voltage line to the first node, the first voltage line to a second node, the second voltage line to the second node, the first voltage line to a third node, and the second voltage line to the third node; a low-pass filter including two or more reactors provided in respective two or more paths of first, second, and third paths, respectively, coupling the first node and a first output terminal, coupling the second node and a second output terminal, and coupling the third node and a third output terminal, and first and second capacitors; and a control section calculating voltage differences across the respective two or more reactors to control operations of the fifth and sixth elements.

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.

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.

Various techniques are described to terminate a differential wire pair using combinations of CMCs, transformers, autotransformers, differential mode chokes (DMCs), and AC-coupling capacitors. The techniques improve the AC common mode insertion loss without attenuating the differential data signals, while easing the requirements of the CMC. In one example, an autotransformer, having a first winding, a second winding, and a center tap, is connected across a PHY, where the center tap provides a low impedance to ground for attenuating common mode noise. A CMC is coupled across the autotransformer and a pair of wires carrying differential data, where the CMC greatly attenuates common mode noise. The requirements of the CMC are reduced due to the autotransformer.

Disclosed herein is a differential mode filter that includes first and second terminal electrodes provided on a first flange part of a core, and first and second wires wound around a winding core part of the core in an opposite direction to each other and connected respectively to the first and second terminal electrodes. The first and second wires cross each other on the winding core part to form a plurality of crossing portions that include first, second, and third crossing portions that are first, second, and third occurrences counting from the one end of the first and second wires, respectively. A first crossing angle between the first and second wires at the first crossing portion is larger than at least one of second and third crossing angles between the first and second wires at the second and third portions, respectively.