An inverter circuit contains a first and second DC sources for providing a DC voltage, a common step-up converter for boosting the DC voltage, an intermediate circuit capacitor connected between the outputs of the common step-up converter, and an inverter for converting the DC voltage provided by the capacitor into an AC voltage. The common step-up converter contains a series circuit having a first inductance and a first rectifier element and is connected between an output of the first DC source and one side of the intermediate circuit capacitor as well as a series circuit which includes a second inductance and a second rectifier element and is connected between an output of the second DC source and another side of the intermediate circuit capacitor. The common step-up converter further contains a common switching element which is connected between the first and second DC sources.