Photoreceptor Circuit Based on Only Metal–Oxide–Semiconductor Transistors

In this study, a photoreceptor circuit composed solely of MOS (metal-oxide-semiconductor) transistors was proposed. Currently, researchers in neuromorphic engineering are focusing on mimicking biological nervous systems using silicon devices. The challenges involved in mimicking biological systems are as significant as their potential. These challenges include circuit complexity, low power consumption, computational difficulty, and the challenge of integrating passive components onto a chip. Biologically, millions of neurons consume only a few watts of energy to process information. Therefore, the main reasons challenging researchers in silicon circuit design are reducing power consumption and making it entirely composed of transistors for applicability within the chip. In this study, the modified photoreceptor circuit holds promise due to its low power consumption and entirely transistor-based design. The circuit design was created in LTspice. Permission for real production in TSMC 90-nm technology was granted for the simulation results. The metal-oxide-semiconductor field-effect transistors used in the design were operated below their threshold. The modified circuit is approximately equivalent to the potential change in a biological photoreceptor cell. The modified circuit has been shown to consume approximately 23 times less power compared to the reference circuits. Furthermore, the modified circuit was analyzed under different background light conditions and was found to operate stably. The proposed circuit, composed entirely of MOS transistors, enhances its compatibility with chip designs. This feature reduces its size, which in turn helps lower costs. Content of this journal is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.