Analog-to-Stochastic Converter Using Magnetic Tunnel Junction Devices for Vision Chips
This work addresses the high power and area overhead of conventional analog-to-stochastic signal conversion, which typically requires two separate stages—analog-to-digital followed by digital-to-stochastic—rendering it unsuitable for energy-efficient vision chips. To overcome this limitation, the study proposes a novel single-step direct conversion approach leveraging the intrinsic probabilistic switching behavior of magnetic tunnel junctions (MTJs). This method significantly reduces hardware complexity and improves energy efficiency. Furthermore, to mitigate the impact of MTJ resistance variability, a compensation mechanism is introduced to enhance conversion accuracy and robustness. Mixed-mode NS-SPICE simulations based on 90 nm CMOS and 100 nm MTJ technologies demonstrate the proposed circuit’s advantages in terms of reduced area, lower power consumption, and improved tolerance to device variations.