摘要 |
The circuits include a floating diffusion, a source supplying a controllable amount of charge to the floating diffusion and a charge coupled device (CCD) reference register for periodically removing a fixed amount of charge from the floating diffusion. A feedback circuit senses the average voltage at the floating diffusion and adjusts the controllable amount of charge supplied to the diffusion to maintain its average voltage level constant. The feedback circuit may be employed automatically to control the direct voltage bias at the input electrode of a DDC signal register. It may alternatively be employed to control a radiation source serving as the input to the system, or to operate a circuit for indicating the frequency at which the reference CCD register is being driven, or as an input to a current mirror amplifier.
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