Circuit and method for image artifact reduction in high-density, highpixel-count, image sensor with phase detection autofocus

Abstract

An image sensor includes an array of multiple-photodiode cells, each photodiode coupled through a selection transistor to a floating diffusion of the cell, the selection transistors controlled by respective transfer lines, a reset, a sense source follower, and a read transistor coupled from the source follower to a data line. The array includes phase detection rows with phase detection cells and normal cells; and a compensation row of more cells. In embodiments, each phase detection row has cells with at least one photodiode coupled to the floating diffusion by selection transistors controlled by a transfer line separate from transfer lines of selection transistors of adjacent normal cells of the row. In embodiments, the compensation row has cells with photodiodes coupled to the floating diffusion by selection transistors controlled by a transfer line separate from transfer lines of selection transistors of adjacent normal cells of the compensation row.