US Patent 8426796 Image sensor having supplemental capacitive coupling node

An image sensor includes a pixel array, a bit line, a supplemental capacitance node line, and a control circuit. The pixel array includes a plurality of pixel cells each including a floating diffusion (“FD”) node and a photosensitive element coupled to selectively transfer image charge to the FD node. The bit line is coupled to selectively conduct image data output from a first group of the pixel cells. The supplemental capacitance node line is coupled to the FD node of a second group of the pixel cells different from the first group. The control circuit is coupled to the supplemental capacitance node line to selectively increase the potential at the FD node of each of the pixel cells of the second group by selectively asserting a FD boost signal on the supplemental capacitance node line.