Abstract: A video signal clamping circuit for adapting the DC level of a composite video signal to the processing range of a digital video signal processing device, includes an isolating capacitor in the analog video signal path and a controlled current source which is connected to a floating isolating-capacitor terminal and charges or discharges the isolating capacitor solely by means of a positive or negative clamping current, with the value and sign of the clamping pulses being digitally controlled by a comparator circuit which compares predetermined reference values of the composite video signal with mode-dependent comparison values.