Micro Four-Transistor CMOS Memristor and Its Application in Cut-off Frequency-Tunable Active Filter Design

A tiny-size four-transistor memristor equivalent circuit is proposed. Based on 180nm/1.8V standard CMOS technology, the designs of the memristor and a memristor-C type active low-pass filter (LPF) circuit are implemented. Compared with the existing discrete memristors in special manufacturing process, the proposed four-transistor memristor with full MOSFET architecture processes significant advantages in terms of circuit area, design complexity and process cost. The memristor element has a simple floating two-port structure, which is more conducive to manufacturing and system integration for large-scale artificial neural networks. After the design and function verification of the proposed memristor, we further employ the memristor to implement a memristor-C type second-order voltage-controlled active low-pass filter circuit, which generally consists of adjustable resistors, capacitors and an high-performance operating amplifier. The schematic design and performance simulation are performed on the Cadence IC design platform. The experimental results show that the electrical characteristics of the proposed memristor are stable and reliable. The memristor-C active LPF built by the memristor achieves the expected low-pass and cut-off frequency-tunable feature in pass bandwidth benefiting to the resistance-adjustable feature of the memristor.