1/3-inch Interline Transfer CCD Image Sensor With Negative Feedback 94dB Dynamic Range Charge Detector

Pixel size of CCD image sensors has recently become smaller to reduce chip size for small optical assembly and to realize a mega-pixel sensor for HD-TV cameras. It is not acceptable, however, to compromise sensor performance for a smaller cell size, and sensitivity and dynamic range must also remain high.1 Buried-channel charge-coupled devices have achieved complete charge transfer with no transfer noise. Therefore, almost all solid-state image sensors use buried-channel CCD scanning circuits. However, conventional charge detectors used with CCDs have relatively high noise. Thus, one of the key technologies for next-generation CCD image sensors will be a superior charge detector that exploits CCD performance. The double-gate floating-surface detector can detect one electron, but its saturation level of 4500 electrons/packet is not sufficient for video-camera sensor application.2,3,4