A 1/2-in 1.3 M-pixel progressive-scan IT-CCD for digital still camera applications

A 1/2-in 1.3 M-pixel progressive-scan interline-transfer charge-coupied-dev ice (IT-CCD) image sensor has been developed for small, low-power mega-pixe l digital still cameras (DSCs). The pixel size as small as 5 mum square mak es small-size progressive-scan IT-CCD (8.3 x 7.1 mm(2)) for the SXGA format . A two-phase-drive horizontal-CCD with phosphorus-implanted storage region s helps reduce the driving voltage to 2.5 V, resulting in the power consump tion of the device being as low as 146 mW, A new source-follower amplifier with separate p-well driver transistors achieves 12% higher gain than that obtained using a conventional amplifier. An overflow drain with a self-adju sting potential barrier can instantly remove superfluous charges in vertica l-CCDs just before an exposure period, which enables DSCs to perform such f unctions as quick auto-focusing and dark-current removal, New dual operatio n modes for still and motion pictures can provide not only high-resolution color signals in a 15-frame/s 1050-line progressive mode but also wide-dyna mic-range color signals in a 30-frame/s 525-line progressive mode. The latt er mode employs a pixel-exchange-and-mix readout operation that helps halve the number of scanning lines with no loss in sensitivity and color informa tion.