US Patent 11284031 Systems and methods for low-power image digitization

A low-power image sensor includes a plurality of light-sensitive pixel cells, a plurality of analog-to-digital converters (ADCs) and image processing circuitry. The image sensor can be disposed in multiple semiconductor layers such that the pixel cells are disposed in a first layer and various other components are disposed in the second layer or between the first layer and the second layer. The image sensor is configured such that the analog output of a pixel cell is sampled by a first ADC and a second ADC within respective first and second dynamic ranges, the second dynamic range being greater than the first dynamic range. The first ADC and the second ADC sample the analog output with different sampling resolutions. The digital outputs of the first ADC and the second ADC are subsequently used by an image processor to generate a pixel value for an image frame.