A resonant converter capable of adaptively tuning a quality factor based on a load, comprising:
- a power switch circuit, receiving an input direct-current (DC) potential for generating a switching potential;
- a resonant tank, receiving the switching potential, including:
- an inductor part, having an inductance tuned according to a first control potential;
- a magnetizing inductor;
- and
- a capacitor part, having a capacitance tuned according to a second control potential;
- a transformer, including a primary winding and a first secondary winding, wherein the primary winding is coupled to the magnetizing inductor;
- an output stage, coupled to a first terminal and a second terminal of the transformer, which includes a rectifying device, a detecting resistor, and an output capacitor;
- an averaging circuit, coupled to a first terminal and a second terminal of the detecting resistor, for obtaining and outputting an average potential, wherein the average potential corresponds to an average current flowing through the rectifying device;
- and
- a controller, receiving the average potential, and outputting the first control potential and the second control potential;
- wherein the inductor part, the magnetizing inductor, and the capacitor part are connected in series, and arranged together between a first node and a first reference ground;
- the first node is coupled to the switching potential;
- the inductor part includes a resonant inductor, at least one auxiliary inductor, and a first auxiliary switch set;
- the capacitor part includes a resonant capacitor, at least one auxiliary capacitor, and a second auxiliary switch set;
- wherein the first auxiliary switch set changes the connecting configuration of the resonant inductor and the auxiliary inductor according to the first control potential;
- wherein the second auxiliary switch set changes the connecting configuration of the resonant capacitor and the auxiliary capacitor according to the second control potential;
- wherein the transformer further includes a second secondary winding;
- the rectifying device includes a first rectifying component and a second rectifying component;
- the first secondary winding and the second secondary winding both have a first terminal and a second terminal;
- a first terminal and a second terminal of the first rectifying component are respectively coupled to the first terminal of the first secondary winding and the first terminal of the detecting resistor;
- a first terminal and a second terminal of the second rectifying component are respectively coupled to the second terminal of the second secondary winding and the first terminal of the detecting resistor;
- the second terminal of the first secondary winding is coupled to the first terminal of the second secondary winding and a second reference ground;
- and
- the output capacitor has a first terminal and a second terminal, the first terminal of the output capacitor is coupled to the second terminal of the detecting resistor, and the second terminal of the output capacitor is coupled to the second reference ground.