Memristive Device's Resistive and Capacitive Switching for Exposure Adaptive Sensing

Ashwani Kumar1 and Aakash Jain2
1Department of Electrical and Computer Engineering, UC San Diego, 2Indian Institute of Information Technology, Design and Manufacturing Technology Kancheepuram


Abstract

This paper presents a use case of emerging memristive kind oxide-based memory (OxRAM) device in active pixel sensor (APS) architecture. The proposed hybrid architecture exploits OxRAM's multiple non-volatile resistance states to achieve variable gain at pixel's column output and OxRAM's nonlinear dynamic capacitance property for overexposure correction at sensing-node. The exposure correction scheme under bright-light condition utilizes the OxRAM as a tunable capacitive load to obtain optimum charge-to-voltage (Q-V)
conversion-gain (CG). The hybrid-pixel architecture shows a ∼ 15 dB relative improvement in pixel dynamic-range (DR) for overexposure case. The implementation of variable-gain hybrid differential amplifier using OxRAM helps to optimize the input-referred noise and also DR at pixel's column output. The hybrid differential-amplifier simulations show multiple gain curves (varying from ∼ 17 dB to ∼ 32 dB) using OxRAM's multiple resistance states. The proposed hybrid-pixel architecture using emerging memristive technology, i.e, OxRAM, presents a proof-of-concept of pixel- level flexibility and reconfigurability for difficult-light conditions.