Abstract: A resonance conversion device and a universal serial bus circuit are provided. The resonance conversion device includes an input filter circuit, a full-bridge LLC converter circuit, a transformer circuit, a rectifier filter circuit, and a controller. The controller is configured to determine whether an indication voltage of a voltage command is less than or equal to a threshold value and to perform the following steps: in response to the indication voltage being less than or equal to the threshold value, controlling the full-bridge LLC converter circuit into a half-bridge operation mode, and regulating the DC output voltage by performing half-bridge burst mode control on the full-bridge LLC converter circuit based on the DC output voltage; and in response to the indication voltage being greater than the threshold value, regulating the DC output voltage by performing full-bridge burst mode control on the full-bridge LLC converter circuit based on the DC output voltage.

Abstract: A planar winding transformer includes a magnetic core set and a multilayer circuit board. The magnetic core set includes two magnetic cores and two magnetic columns. The two magnetic cores are parallel to each other. The multilayer circuit board is disposed between two magnetic cores, and two magnetic columns penetrate through the multilayer circuit board. The multilayer circuit board includes two low voltage winding layers and one high voltage winding layer. Two low voltage winding layers are connected to each other in parallel, and the high voltage winding layer is disposed between two low voltage winding layers. When the high voltage winding layer receives a polarity current, at least one of the low voltage winding layers generates a corresponding induced current. Two magnetic cores and two magnetic columns form a closed path for magnetic flux.

Abstract: A resonance conversion device and a universal serial bus circuit are provided. The resonance conversion device includes an input filter circuit, a full-bridge LLC converter circuit, a transformer circuit, a rectifier filter circuit, and a controller. The controller is configured to determine whether an indication voltage of a voltage command is less than or equal to a threshold value and to perform the following steps: in response to the indication voltage being less than or equal to the threshold value, controlling the full-bridge LLC converter circuit into a half-bridge operation mode, and regulating the DC output voltage by performing half-bridge burst mode control on the full-bridge LLC converter circuit based on the DC output voltage; and in response to the indication voltage being greater than the threshold value, regulating the DC output voltage by performing full-bridge burst mode control on the full-bridge LLC converter circuit based on the DC output voltage.

Abstract: A printed circuit board of a planar transformer includes a first column hole, a second column hole, and a plurality of winding layers. At least one of the winding layers includes a first winding and a second winding connected in series. The first winding surrounds the first column hole and has a first opening direction. The second winding surrounds the second column hole and has a second opening direction. The first opening direction is different from the second opening direction. Consequently, the windings on the plurality of layers may be connected in series through conductive holes of the PCB to increase the number of winding turns.

Abstract: A planar winding transformer includes a magnetic core set and a multilayer circuit board. The magnetic core set includes two magnetic cores and two magnetic columns. The two magnetic cores are parallel to each other. The multilayer circuit board is disposed between two magnetic cores, and two magnetic columns penetrate through the multilayer circuit board. The multilayer circuit board includes two low voltage winding layers and one high voltage winding layer. Two low voltage winding layers are connected to each other in parallel, and the high voltage winding layer is disposed between two low voltage winding layers. When the high voltage winding layer receives a polarity current, at least one of the low voltage winding layers generates a corresponding induced current. Two magnetic cores and two magnetic columns form a closed path for magnetic flux.

Abstract: A transformer includes a magnetic core set and 2N pairs of windings. The magnetic core set includes a first magnetic core, a second magnetic core, a first magnetic column, and a second magnetic column. Each of the pairs of windings includes a high-voltage side winding and a low-voltage side winding. Each of the pairs of the windings surrounds one of the first and the second magnetic columns. The surrounding direction of the high-voltage side windings surrounding the firs magnetic core is opposite to the surrounding direction of the high-voltage side windings surrounding the second magnetic core.