In Depth Analysis of The CMOS OTA-Based Floating Inductors

Abstract

Commonly known, the gyrator-based OTA simulated floating inductor can be divided into two categories; 3-OTA and 4-OTA structure which perform identically in the ideal phenomena where all OTA's nonidealities i.e. parasitic elements, effect of finite open-loop bandwidth and noise have been neglected. It has been found in R. Banchuin et al. (2005) that the 4-OTA-based floating inductor has better functional and noise performances than its 3-OTA counterpart in the practical phenomena where all of the cited nonidealities included. However, this conclusion has been made based upon the assumption that all OTAs are of the bipolar type. Therefore, due to the rise of the age of CMOS technology; an attempt to find the difference between the 3-CMOS-OTA and 4-CMOS-OTA based floating inductors has been made. Including all of the cited nonidealities, the 4-CMOS-OTA-based floating inductor also has both better functional and noise performances than its 3-CMOS-OTA counterpart. This conclusion strengthens the superiority of the 4-OTA structure over the 3-OTA counterpart since it has been found to be independent of the basis technology and also supports the design guideline proposed in R. Banchuin et al. (2005)