Conceitos essenciais
A novel transimpedance amplifier (TIA) design utilizing a memristor-based automatic gain control (AGC) mechanism to significantly extend the dynamic range of optical signal acquisition.
Resumo
The paper presents a novel approach to designing a high dynamic range transimpedance amplifier (TIA) for optical signal acquisition. The key innovation is the incorporation of a memristor device into the TIA's feedback network to provide automatic gain control (AGC) capabilities.
The proposed TIA operates as follows:
- The memristor is initially in a high resistance state (HRS), allowing the TIA to have high gain and sensitivity for low-level input signals.
- As the input current increases and approaches the maximum current the TIA can amplify before saturation, the circuit output voltage becomes high enough to switch the memristor to a low resistance state (LRS).
- The memristor's resistance transition from HRS to LRS reduces the TIA's gain, enabling it to handle high input currents without saturating.
- This memristor-based AGC mechanism extends the TIA's dynamic range by the ratio of the memristor's Roff/Ron resistance.
The authors fabricated a prototype circuit on a printed circuit board (PCB) and conducted both simulations and experimental measurements to validate the proposed design. The results demonstrate a remarkable 40 dB increase in the TIA's dynamic range compared to traditional resistor-based TIAs.
The paper also discusses the reading and resetting circuits required to monitor and control the memristor's state. Challenges related to cycle-to-cycle variations in the memristor's parameters and the need for an explicit reset operation are identified, motivating further research into using volatile memristors to simplify the circuit.
Estatísticas
The proposed TIA design enables a 40 dB increase in dynamic range compared to traditional resistor-based TIAs.
The memristor used in the prototype has an Roff/Ron ratio of approximately 100.
Citações
"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."
"For the memristor device we used, the dynamic range can be extended by approximately 40dB compared to resistor-based TIAs."