A transformer includes: a magnetic core including a lower magnetic structure and an upper magnetic structure; a printed circuit board arranged between the lower magnetic structure and the upper magnetic structure and including a core hole through which a midsection of the magnetic core penetrates, a primary coil, a secondary coil, a primary via-hole formed at an end of the printed circuit board and electrically connected to the primary coil, and a secondary via-hole formed at another end of the printed circuit board and electrically connected to the secondary coil; a primary pin inserted into the primary via-hole; a secondary pin inserted into the secondary via-hole; an insulating block into which a portion of the printed circuit board is inserted; and a mount on which the printed circuit board and the insulating block are mounted.

A planar inductor may include a first coil and a second coil. The first coil may include a first trace that forms a first set of turns. The second coil may include a second trace that forms a second set of turns. A distance between the turns of the first set of turns may be equal to a distance between the turns of the second set of turns. A width of the first trace may be equal to a width of the second trace. The first coil and the second coil may be physically positioned or sized according to a/b in which a represents the width of the first trace and b represents the distance between the turns of the first set of turns.

A transformer of the symmetric-asymmetric type includes comprising a primary inductive circuit and a secondary inductive circuit formed in a same plane by respective interleaved and stacked metal tracks. A first crossing region includes a pair of connection plates facing one another, with each connection plate having a rectangular shape that is wider than the metal tracks, and diagonally connected to tracks of the secondary inductive circuit.

Isolators for signals and/or powers transmitted between two circuits configured to operate at different voltage domains are provided. The isolators may have working voltages, for example, higher than 500 Vrms, higher than 1000 Vrms, or between 333 Vrms and 1800 Vrms. The isolators may have a fully symmetrical configuration. The isolators may include a primary winding coupled to a driver and a secondary winding coupled to a receiver. The primary and secondary windings may be laterally coupled to and galvanically isolated from each other. The primary and secondary windings may include concentric traces. The primary and secondary windings may be fabricated using a single metallization layer on a substrate.

Systems and methods for improving winding losses in transformers are disclosed. In one aspect, a transformer includes a first magnetic core having an interior portion and an exterior portion, a second magnetic core in contact with the interior and exterior portions, a plurality of primary and secondary windings formed around the interior portion, where the interior portion is formed from one of a first magnetic material and a second magnetic material, and the exterior portion is formed from one of the first magnetic material and the second magnetic material, where the first magnetic material has different properties than the second magnetic material. In another aspect, the first magnetic core includes a third portion that extends across and is in contact with the interior portion and the exterior portion, where the third portion is formed from one of the first magnetic material and the second magnetic material.

A planar transformer comprising a printed circuit board; a primary planar winding disposed within the printed circuit board; a secondary planar winding disposed within the printed circuit board; a magnetic material disposed within the printed circuit board between the primary planar winding and the secondary planar winding, the magnetic material configured to generate a secondary magnetic flux path; and a magnetic core disposed around and through the printed circuit board and magnetically coupled to the primary planar winding and the secondary planar winding, the magnetic core configured to generate a primary magnetic flux path.

This application provides a planar transformer and a switching power adapter. The planar transformer includes a PCB winding and two magnetic cores. The two magnetic cores wrap two sides of a winding body of the PCB winding to form a closed magnetic loop. A first group of welding points is disposed on a primary-side wire side of the PCB winding, and a second group of welding points is disposed on a secondary-side wire side of the PCB winding. The planar transformer is directly welded to an external circuit board by using the first group of welding points and the second group of welding points. In this way, no pin needs to be welded on the PCB winding board. In addition, the planar transformer can be vertically installed on the external circuit board by using the first group of welding points and the second group of welding points.

An apparatus has a laminate substrate that has a first surface and an opposite second surface. A laminate transformer is located within the laminate substrate between the first surface and the second surface. The transformer has a first coil adjacent the first surface and a second coil adjacent the second surface. A magnetic core element on the first surface overlaps a portion of the first coil. A lead frame on the first surface is spaced apart from the magnetic core element. A portion of the lead frame overlaps a portion of the first coil to provide a thermal conductive path.

Systems and methods for improving winding losses in transformers. In one aspect, a transformer includes a first magnetic core having a first portion in contact with a second magnetic core and a second portion separated from the second magnetic core by a distance d, a plurality of primary windings formed around the second portion, a first secondary winding forming a first layer having a first inner diameter, a second secondary winding forming an n.sup.th layer having a second inner diameter. The plurality of primary windings are positioned between the first layer and the n.sup.th layer, where the plurality of primary windings, and the first secondary winding and the second secondary winding are formed around the second portion, and a difference between the first inner diameter and the second inner diameter defines a distance y, and a ratio of distance y to distance d is between 0.01 to 10.

A transformer for a power converter, comprising: a first auxiliary subcore, a central subcore, and a second auxiliary subcore, each respective subcore comprising a lower plate, at least one pair of central spacers, and an upper plate, the lower plate, at least one pair of central spacers, and the upper plate of each subcore, being respectively separated by a gap; the first auxiliary subcore and the central subcore being separated by a gap; the second auxiliary subcore and the central subcore being separated by a gap; a primary coil, encircling a first spacer of the first auxiliary subcore and a first spacer of the central subcore; and a secondary coil, encircling a second spacer of the second auxiliary subcore and a second spacer of the central subcore.