Analysing and Measuring the Performance ofMemristive Integrating Amplifiers

TL;DR

This paper analyzes a memristor-based integrating amplifier used for neural signal recording, proposing new validation methods for key performance metrics considering its unique transient behaviour during integration.

Contribution

It introduces alternative definitions for performance metrics of memristive amplifiers, accounting for their dynamic operating points and transient behaviour during integration.

Findings

New validation methods for gain, bandwidth, and offset sensitivity.

Insights into design trade-offs for memristor-based amplifiers.

Analysis of transient behaviour during neural signal amplification.

Abstract

Recording reliably extracellular neural activities isan essential prerequisite for the development of bioelectronicsand neuroprosthetic applications. Recently, a fully differential,2-stage, integrating pre-amplifier was proposed for amplifyingand then digitising neural signals. The amplifier featured a finelytuneable offset that was used as a variable threshold detector.Given that the amplifier is integrating, the DC operating pointkeeps changing during integration, rendering traditional analysis(AC/DC) unsuitable. In this work, we analyse the operation ofthis circuit and propose alternative definitions for validating thenecessary key performance metrics, including: gain, bandwidth,offset tuning range and offset sensitivity with respect to thememory states of the employed memristors. The amplificationprocess is analysed largely through investigating the transientbehaviour during the integration phase. This benchmarkingapproach is finally leveraged for providing useful insights anddesign trade-offs of the memristor-based integrating amplifier.