The effects of smear on antiblooming protection and dynamic range of interline CCD image sensors

The effects of a smearing signal on the dynamic range and the amount of antiblooming protection of an interline CCD image sensor are presented. It is shown that there is a tradeoff between these two parameters, and that they are directly related by the amount of smear. These relationships are analyzed for both constant-integration time and constant-irradiance modes of operation. For the constant-irradiance model of operation it is shown that in order to maintain 90% of the maximum dynamic range and an antiblooming protection of 300×, the smear signal must be less than 0.037%. For the constant integration-time mode of operation, it is shown that in order to maintain 75% of a particular device´s maximum dynamic range and the same amount of antiblooming protection the smear signal must be less than 0.0074%. It is also found in this mode that this relationship between antiblooming protection and the amount of linear dynamic range is exponential, and dependent on the antiblooming structure´s nonideality factor and the individual photodetector´s capacitance