Energy Efficient Pixel-Parallel Read-Out Circuits for Digital Image Sensors Using Cross-Layer Pixel Depth Control

Digital pixel sensors with pixel-parallel readout provide opportunities for high frame rate and high resolution in 3D integrated camera platforms with in-sensor machine learning. The active energy consumption of the digital pixels at the sensor front end is a key performance parameter for applications involving smart cameras. This work proposes a novel digital pixel design that utilizes cross-layer feedback to improve active energy efficiency of pixels in image sensors. An algorithm-circuit co-simulation of
$336\times256$
image sensor in 65nm CMOS for an object detection task shows 58% active energy saving in digital pixel circuits, while maintaining accuracy of end task.