INTEGRATED CIRCUIT FOR TELEVISION RECEIVERS COMPRISING A SYNCHRONIZATION SIGNAL SEPARATOR CIRCUIT WITH A CLAMP LEVEL CONTROL CIRCUIT

摘要

To prevent the separation-level shift occurring in the clamping circuit during the transmitted vertical synchronizing pulses or during prolonged interference pulses, a pulse opening an electronic switch (S) inserted between the clamping circuit and one RC section thereof is generated by means of a coincidence stage (KO), a gate circuit (TS), an inverter (I), and an AND gate (U). The clamping circuit is thus unblocked only during the horizontal synchronizing pulses, so that no shift of the separation level can occur during the vertical synchronizing pulses or during any interference pulses in the composite color signal (F).