Resonant dc converter

A resonant DC converter, used to convert a DC input voltage into a DC output voltage in order to provide a load with power supply, comprising:

• a front-end conversion circuit, comprising a full-bridge resonant DC conversion circuit and a voltage-type auto charge pump circuit, wherein the full-bridge resonant conversion circuit is provided with a positive voltage terminal at an input side in coupling with a first active switching element and a second active switching element in parallel, and a negative voltage terminal at the input side in coupling with a third active switching element and a fourth active switching element in parallel, the first active switching element and the third active switching element are coupled in series with a positive voltage terminal of a first inductor, the positive voltage terminal of the first inductor is coupled with one common node between the first active switching element and the third active switching element, a negative voltage terminal of the first inductor is coupled in series to a semi-resonant circuit of the voltage-type auto charge pump circuit, the semi-resonant circuit contains a second inductor and a capacitor coupled with the second inductor in parallel, the voltage-type auto charge pump circuit further includes a second capacitor coupled in series with the semi-resonant circuit, and the second capacitor is coupled with one common node between the second active switching element and the fourth active switching element;
• and
• a transformer, wherein a primary side of the transformer is coupled to the front-end conversion circuit and to the second capacitor in parallel, a secondary side of the transformer is coupled to a rear-end conversion circuit which is electrically coupled with the front-end conversion circuit through the transformer.