Chua's Oscillator With OTA Based Memcapacitor Emulator

A charge-controlled memcapacitor emulator design based on the current-mode technique has been proposed in this research work. The physical realization of a memcapacitor is an open problem that motivates creating newer designs for memcapacitor emulator circuits. The memcapacitor emulator comprises an operational transconductance amplifier (OTA), an active component and has additional passive elements. Memcapacitor, abstracted to have a (pinched) hysteresis loop, is emulated in this work, can be also observed as a nonlinear capacitor with memory in its physical form. The simulations are carried out using 0.18 μm (Taiwan Semiconductor Manufacturing Company) TSMC technology and a ±1.2 V supply voltage to analyse robustness of design through process corner, temperature variation, and non-volatility. Experimental validations are performed using ICs CA3080 on breadboard. An application of chaotic oscillator and adaptive learning circuit using a memcapacitor emulator circuit is shown as a practical case study.

I. Introduction

Memcapacitors are the mem-elements [1] that connect the time integrals of charge and voltage. This can be modelled in both voltage-controlled and charge-controlled memcapacitive system topologies. In the case of memcapacitor, the hysteresis loop is obtained in the charge-voltage plane. Its capacitance value, which is nothing but the memcapacitance, is defined by its history, which shows a nonlinear variation.