An apparatus, comprising: - a first transistor element with at least three terminals (22, 24, 26), - wherein a first terminal is supplied with a first voltage, and - wherein a second terminal is supplied with a second voltage, - a first switching unit, - wherein a third terminal is connected to ground potential via the first switching unit, - wherein the first transistor element comprises a predefined threshold voltage, - wherein the first voltage and the second voltage are predefined alternating voltages, and - wherein the first transistor element is configured such that in case a differential voltage between the first predefined alternating voltage and the second predefined alternating voltage is higher than the predefined threshold voltage and the first switching unit is not conductive the third terminal is charged with the first predefined alternating voltage, wherein the apparatus further comprises: - a second transistor element, - wherein a first terminal of the second transistor element is connected to the third terminal of the first transistor element, and - wherein a second terminal of the second transistor element is connected to ground potential; and - at least a third transistor element, the third transistor element comprising - a second terminal supplied by an input signal, and - a third terminal connected to ground potential via a capacitor element - wherein a first terminal of the third transistor element is connected to the third terminal of the second transistor element. - a first transistor element with at least three terminals (22, 24, 26), - wherein a first terminal is supplied with a first voltage, and - wherein a second terminal is supplied with a second voltage, - a first switching unit, - wherein a third terminal is connected to ground potential via the first switching unit, - wherein the first transistor element comprises a predefined threshold voltage, - wherein the first voltage and the second voltage are predefined alternating voltages, and - wherein the first transistor element is configured such that in case a differential voltage between the first predefined alternating voltage and the second predefined alternating voltage is higher than the predefined threshold voltage and the first switching unit is not conductive the third terminal is charged with the first predefined alternating voltage, wherein the apparatus further comprises: - a second transistor element, - wherein a first terminal of the second transistor element is connected to the third terminal of the first transistor element, and - wherein a second terminal of the second transistor element is connected to ground potential; and - a second transistor element, - wherein a first terminal of the second transistor element is connected to the third terminal of the first transistor element, and - wherein a second terminal of the second transistor element is connected to ground potential; and - at least a third transistor element, the third transistor element comprising - a second terminal supplied by an input signal, and - a third terminal connected to ground potential via a capacitor element - wherein a first terminal of the third transistor element is connected to the third terminal of the second transistor element. - a second terminal supplied by an input signal, and - a third terminal connected to ground potential via a capacitor element - wherein a first terminal of the third transistor element is connected to the third terminal of the second transistor element.