In order to provide a switching power supply apparatus operable at a high voltage, a plurality of identical circuit elements may be connected in series to relax requirements for circuit elements, such as switching elements, for example, withstand voltage performance.

However, in the case of the switching power supply apparatus provided with the bootstrap circuit, when synchronously turning on and off two series-connected switching elements, it is not possible to keep a sufficiently high voltage to operate the drive circuit in the capacitor of the bootstrap circuit. As a result, the two switching elements cannot be simultaneously turned on, and one of the switching elements may be broken due to overvoltage. Therefore, it is required to control the plurality of switching elements to synchronously turn on and off with the bootstrap circuit.

An object of the present disclosure is to provide a switching circuit apparatus capable of controlling a plurality of switching elements to synchronously turn on and off with a bootstrap circuit. Another object of the present disclosure is to provide a power converter apparatus provided with at least one such switching circuit apparatus.