Four quadrant analog multiplier based memristor emulator using single active element

Abstract

This paper presents a novel Four Quadrant Analog Multiplier (FQAM) circuit and its applications using a single active element Current Differencing Transconductance Amplifier (CDTA) and two NMOS. This circuit has a cascadability feature as it produces current and voltage outputs at high and low impedance ports, respectively. It offers additional features such as resistor-less realization, operability in voltage and trans-conductance mode, and configurable structure. Further, the FQAM circuit is configured to develop a memristor emulator based on the proposed mathematical analogy. The proposed memristor circuit contains active elements (one CDTA, two NMOS, and one Inverting Voltage buffer) and only one grounded capacitor. It offers tunability using the transconductance gain of the CDTA block. Also, the proposed memristor emulator circuit doesn’t contain any additional multiplier block. The emulator circuit can be operated in both the Incremental and the Decremental mode of memristance variation. The results demonstrate the non-volatile property as well as hysteresis behavior for the wide frequency range. The effects of statistical variation in passive component, threshold voltage, and aspect ratios on the proposed circuits using Monte-Carlo simulation have been estimated. Also, the impact of non-idealities and the parasitic effects of the CDTA on the proposed circuits are investigated. In last, the capacitor-less version of the memristor emulator and its hysteresis characteristics have been demonstrated. The simulation results obtained using HSPICE, are agreed well with the theoretical analysis.