Chargedcoupled

Chargedcoupled is not a standard term in electronics. It is most commonly encountered as charge-coupled or charge-coupled device (CCD), a class of semiconductor devices that transfer electrical charge through a sequence of capacitive wells by clocking voltages. In a typical CCD image sensor, photons generate electron-hole pairs in silicon; electrons accumulate in potential wells formed under gate electrodes. By applying a carefully timed series of clock voltages, the charge packets are shifted stepwise along a chain to an output node where they are converted to a voltage signal and digitized.

History and usage: CCDs were developed in the late 1960s by Willard S. Boyle and George E. Smith at Bell Labs and became widespread in consumer and professional imaging through the 1990s and 2000s. They remain preferred in some high-end applications such as astronomy and spectroscopy due to high quantum efficiency and low noise, though complementary metal-oxide-semiconductor (CMOS) sensors have become dominant in many consumer devices.

Technical variants include full-frame CCDs, frame-transfer CCDs, and interline-transfer CCDs, differing mainly in how they transfer charge and read out without shading artifacts. Advantages of CCDs include high image quality, low dark current, and excellent uniformity; drawbacks include more complex clocking, higher cost, and greater power use, with sensitivity to radiation in space environments.

Beyond imaging, the term charge-coupled can also refer to general techniques of moving charge in integrated circuits, such as charge-coupled logic (CCL) or charge-domain shifting used in analog shift registers, though these are less common today.

See also: charge-coupled device, CMOS image sensor, frame-transfer, back-illuminated CCD.