High-end digital still cameras rely on charge-coupled devices (CCDs) to provide a quality picture. The CCD is a two-dimensional sensor that collects photons and converts these to electrical charge. Today’s CCDs can easily contain over ten million bits of information. This large scope makes it impractical to read all the data out in parallel. Instead the data is passed out serially pixel-by-pixel and row-by-row. The circuitry required to sequence the data out consists of a number of clock drivers operating at various voltages. These clock drivers are broken into both horizontal and vertical clock drivers. Analog semiconductor companies develop these integrated circuits.
Colon, Rafeal; Combs, Trevor; Schweinfort, Willi; and Munkongsujarit, Songphon, "Vertical CCD Clock Driver Test Time Optimization" (2008). Engineering and Technology Management Student Projects. 1053.