Linear output stage for charge-coupled circuits

A method for the operation of a linear output stage system for charge coupled circuits having a linear output stage of a charge coupled circuit on a semiconductor substrate with an evaluator electrode over the substrate connected to a first shift pulse train by a switching transistor controlled by a switching pulse train, a following electrode over the substrate connected to a fixed auxiliary potential, and a diode in the substrate connecting to a first auxiliary pulse train, an input stage also being provided connecting to the output stage evaluator electrode and having a second auxiliary pulse train, comprising the steps of:

• fully absorbing a signal charge when the evaluator electrode carries a fixed potential;
• at a first time which occurs before the end of the first shift pulse train, switching off the switching pulse train so as to block the switching transistor;
• following a first interval of time switching on at a second time the first auxiliary pulse train and a second auxiliary pulse train in the input stage provided for the signal transfer, the first auxiliary pulse train setting up the surface potential beneath the evaluator electrode such that a difference between itself and the fixed auxiliary potential exceeds a start voltage;
• at a third time switching off the second auxiliary pulse train;
• following a second interval of time switching off the first auxiliary pulse train at a fourth time;
• and the switching pulse train switching the switching transistor conductive again before the beginning of a last shift pulse train of the charge coupled device.

A linear output stage system for charge-coupled circuits, comprising:

• a charge-coupled circuit on a semiconductor substrate;
• an output stage at one end of the charge-coupled circuit;
• the output stage having an evaluator electrode over the substrate, a follower electrode over the substrate adjacent the evaluator electrode, and a diffused region in the substrate as a diode adjacent the follower electrode;
• the output stage feeding a following stage at its evaluator electrode and also having a switching transistor whose gate terminal is connected to a switching pulse train means for blocking the switching transistor during a read-out process and switching it conductive for a specific length of time between two read-out processes, the switching transistor being inserted into the output stage between a pulse train line supplying a first shift pulse train and said evaluator electrode;
• said switching pulse train means occurring at a time such that prior to the read-out process said first shift pulse train is connected through to the evaluator electrode so that when the evaluator electrode receives the signal charge it has a fixed bias rather than being floating, and during the read-out process the first shift pulse train is isolated from the evaluator electrode;
• and the output stage follower electrode being connected to an auxiliary potential and the diode being connected to a pulse train source means for supplying a first auxiliary pulse train for creating a given surface potential in the output stage.