Active pixel array with matching analog-to-digital converters for image processing

Abstract

An imaging device includes a plurality of photo-diodes arranged in a plurality of columns on a single Complementary Metal Oxide Semiconductor (CMOS) substrate. A plurality of analog-to-digital converters (ADCs) corresponding to the plurality of columns of photo-diodes are arranged on the substrate, with each ADC having an input coupled to outputs of the photo-diodes in the corresponding column. Parallel processing of the data streams produced by the multiple ADCs improves the bandwidth of the imaging device. The ADCs have one or more capacitors based on a reference capacitor that are configured so that the corresponding capacitors for different ADCs are substantially equal across the CMOS substrate. As such, image variation and streaking across the columns of photo-diodes is minimized or eliminated. The reference capacitors of the ADCs are above a minimum capacitance value, determined by a maximum variation of the reference capacitors across the substrate.

Dependencies are inferred from the claim text.