Transimpedance Amplifier with Automatic Gain Control Based on Memristors for Optical Signal Acquisition

Transimpedance amplifiers (TIA) play a crucial role in various electronic systems, especially in optical signal acquisition. However, their performance is often hampered by saturation issues due to high input currents, leading to prolonged recovery times. This paper addresses this challenge by introducing a novel approach utilizing a memristive automatic gain control (AGC) to adjust the TIA's gain and enhance its dynamic range. We replace the typical feedback resistor of a TIA with a valence-change mechanism (VCM) memristor. This substitution enables the TIA to adapt to a broader range of input signals, leveraging the substantial OFF/ON resistance ratio of the memristor. This paper also presents the reading and resetting sub-circuits essential for monitoring and controling the memristor's state. The proposed circuit is evaluated through SPICE simulations. Furthermore, we extend our evaluation to practical testing using a printed circuit board (PCB) integrating the TIA and memristor. We show a remarkable 40 dB increase in the dynamic range of our TIA memristor circuit compared to traditional resistor-based TIAs.