Abstract: A noise filter may include: a first conductive line extending between an input and an output terminal portion, wherein the first conductive line includes an input-side conductive line extending between the input terminal portion and a branch portion, and an output-side conductive line extending between the output terminal portion and the branch portion; a second conductive line connected to the branch portion of the first conductive line, wherein a capacitor is on the second conductive line; and a magnetic body surrounding at least a part of a circumference of at least a part of the first conductive line, wherein the magnetic body is configured to magnetically couple the input-side and the output-side conductive lines such that at least an equivalent series inductance of the capacitor and a parasitic inductance of the second conductive line are reduced by a mutual inductance between the input-side conductive line and the output-side conductive line.

Abstract: A noise filter may include: a first conductive line extending between an input and an output terminal portion, wherein the first conductive line includes an input-side conductive line extending between the input terminal portion and a branch portion, and an output-side conductive line extending between the output terminal portion and the branch portion; a second conductive line connected to the branch portion of the first conductive line, wherein a capacitor is on the second conductive line; and a magnetic body surrounding at least a part of a circumference of at least a part of the first conductive line, wherein the magnetic body is configured to magnetically couple the input-side and the output-side conductive lines such that at least an equivalent series inductance of the capacitor and a parasitic inductance of the second conductive line are reduced by a mutual inductance between the input-side conductive line and the output-side conductive line.

Abstract: If the capacitance of a snubber capacitor, the inductance of a coil and the magnitude of a resistor are specified such that the resonance frequency of the snubber circuit coincides with the ringing frequency of the transistor, and the impedance of the first loop at the resonance frequency becomes smaller than the impedance of the second loop at the resonance frequency, a current component due to ringing flows in the snubber circuit, and energy is consumed by the resistor. Therefore, it is possible to quickly converge ringing.

Abstract: If the capacitance of a snubber capacitor, the inductance of a coil and the magnitude of a resistor are specified such that the resonance frequency of the snubber circuit coincides with the ringing frequency of the transistor, and the impedance of the first loop at the resonance frequency becomes smaller than the impedance of the second loop at the resonance frequency, a current component due to ringing flows in the snubber circuit, and energy is consumed by the resistor. Therefore, it is possible to quickly converge ringing.