Calibration of the Nauta structure differential OTA

Abstract

This work identifies properties and behaviours of a differential operational transconductance amplifier (OTA) consisting of six inverters, first proposed by Bram Nauta, that are exploited to design a digital calibration technique for a modified, digitally-controllable version of the OTA. The calibration technique is designed to reliably tune the OTA for high gain in such a way that very little additional analogue hardware is required, that then could be implemented as an integrated on-chip solution.