Abstract
An active damping circuit capable of performing soft-switching comprises a bidirectional transducer and an active damper. The bidirectional transducer is connected between an input power source and a load end. The bidirectional transducer includes at least a voltage boost circuit, a voltage reduction circuit and a filtering inductor, wherein the filtering inductor is disposed between the voltage boost circuit and the voltage reduction circuit while a reverse recovery current is generated when the voltage boost circuit and the voltage reduction circuit make the switch. The active damper is connected with the filtering inductor of the bidirectional transducer in parallel. Accordingly, when the voltage boost circuit and the voltage reduction circuit make the switch and generate the reverse recovery current, the active damper provides an energy recovery path to the load end, so as to release the energy of the filtering inductor and thereby solve the problem of surge voltage generated during the switch process of the transducer. As a result, the transduction efficiency of the whole circuit is improved.