Selfputing: A 0.57 μW @ 15 fps Vision Chip with Self-powered In-Pixel Computing and In-Memory Computing for Visual Perception on the Edge

This paper presents an intelligent vision chip featuring self-powered in-pixel computing and in-memory computing (Selfputing) for distributed vision sensor nodes. The sensed light signal is processed with computing-in-pixel (CIP) scheme in the pixel array utilizing light-induced photocurrent to extract convolutional features. The output of CIP array is processed by SRAM-based charge-domain computing-in-memory (CIM) array to derive the image classification result. A power-managementunit driven by energy-harvesting photovoltaic (PV) cell is designed to power the CIP and CIM array. The Selfputing chip is fabricated in 180 nm CMOS process and consumes $0.57 \mu \mathrm{~W}$ power at a frame rate of 15 fps with 95.1% accuracy on MNIST dataset, achieving self-powered operation when driven by a PV cell with $1.26 \mu \mathrm{~W}$ harvesting power.