TiO_2−x–TiO₂ Memristor Applications for Programmable Analog VLSI Circuits at 45 nm CMOS Technology Node

Abstract

Memristor-CMOS (MCM) technology combines CMOS processing with nano-scale memristors enabling a significant reduction in the silicon area as compared to CMOS-only counterparts. Moreover, the non-volatile memory characteristics of the memristor offers opportunity for new and innovative MCM hybrid VLSI circuits that can outperform conventional CMOS designs. MCM based hybrid, homogeneous re-configurable architectures have already gained immense popularity among digital VLSI designers. This paper explores application of $TiO_{2-x}$–$TiO_{2}$ charge trap memristor for programmable analog VLSI applications. The threshold adaptive memristor SPICE model has been used to evaluate the performance of the memristor in electronic design automation tool in conjunction with 45 nm CMOS devices. A digitally controlled MCM analog buffer, MCM binary phase shift keying modulator and a variable gain MCM differential amplifier has been presented in this paper. The MCM analog buffer has 81% greater gain-bandwidth product than the corresponding CMOS-only buffer and has an attenuation of $-32$ dB when the control signal is low. A MCM differential amplifier is proposed whose gain can be varied in both directions by shifting the operating point of the memristor through control signals, proving the advantages of using MCM technology for automatic gain control and other programmable analog VLSI applications. A MCM BPSK modulator circuit is also proposed which occupies 37.2% lesser silicon area than the conventional CMOS-only BPSK modulators, thus illustrating the utility of memristor in analog switching circuits.