A surgical device having a step-up converter, a power supply unit and a control arrangement. The step-up converter converts a mains AC voltage to an intermediate circuit voltage and energizes a DC intermediate circuit. The power supply unit includes an inverter connected to the intermediate circuit. The power supply unit also includes a transformer that has a primary coil connected to the inverter and a secondary coil for energizing a load. The control arrangement includes a PFC control circuit connected in a controlling manner to the step-up converter. The control arrangement further includes an operation control circuit connected in a controlling manner to the power supply unit. The PFC control circuit and operation control circuit are connected to each other via a digital communication interface.