Hybrid CMOS-OxRAM Image Sensor for Overexposure Control

Abstract

This paper presents a first of its kind unique application of OxRAM devices in CMOS image sensor pixels. Our proposed hybrid CMOS-OxRAM pixel circuit exploits the non-linear capacitive and resistive properties of OxRAM device to control image overexposure autonomously. HfOx based OxRAM device is used as a programmable capacitive load in a conventional 4T-APS (active pixel sensor) circuit. Our solution exploiting HfOx based OxRAM devices, improves the dynamic range of individual pixels by a factor of ~2.45 (or 7.8 dB), and capacitance density by a factor of ~5 at 180 nm node.