Image sensor having separate, stacked, pixel array, dram, and logic/analog-digital converter integrated circuit die

Abstract

A multiple IC, buffered, image sensor has a first IC with pixels, selection transistors, and interconnect coupling selected pixels with first inter-die bond pads that convey image data to a second IC having logic and ADCs. The ADCs having inputs coupled to selected pixels and outputting through-silicon vias and inter-die bond pads to a third IC coupled to buffer raw image data in DRAM. A method includes capturing images with array pixel IC divided into sub-arrays each coupled to a separate, associated, ADC through inter-die bonds, scanning the sub-arrays and converting the image data to digital image data; and transferring the digital image data over inter-die bonds into buffers in DRAM.