US Patent 11870346 DC-DC converter

A DC-DC converter includes: a first capacitor, a second capacitor, a first switch device, a second switch device, a third switch device, a fourth switch device, a flying capacitor, where one end of the flying capacitor is coupled to the first intermediate node, the other end of the flying capacitor is coupled the second intermediate node; and the protective circuit, including a clamping unit and a buffering unit, where when a voltage between the positive end of the bus and the negative end of the bus increases, the clamping unit clamps the first switch device to a voltage of the first capacitor, and clamps the fourth switch device to a voltage of the second capacitor, and the buffering unit reduces a current flowing through the clamping unit and the flying capacitor.