Analysing and Measuring the Performance ofMemristive Integrating Amplifiers

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.