Patent ID: 7109784

Claim:
A charge transfer device comprising: a semiconductor substrate; a first charge transfer region formed in said semiconductor substrate, said first charge transfer region having a first input source, a first gate electrode, and a first output portion; a second charge transfer region coupled to the first charged transfer region and also formed in said semiconductor substrate, said second charge transfer region having a second input source coupled to said first output portion, a second gate input electrode in a second output portion; and a bias circuit for accepting a control voltage reference signal applied to the first charge transfer region, and for developing at least a first reference voltage φ A , the reference voltage corresponding to a surface potential of at least a portion of the first charge transfer region, and also developing therefrom a second reference voltage, φ B , the second reference voltage representing a surface potential of the second charge transfer region, and for further deriving a bias voltage to be applied to control the second charge transfer region.