High performance carbon nanotube based folded cascode operational transconductance amplifiers

In this work, we propose and simulate two new folded cascode operational transconductance amplifiers (FC-OTAs). The novelty of the proposed OTAs is the use of carbon nanotube field effect transistors (CNT-FET) in their design. The two proposed OTAs include one employing the combination of n-type CNT-FETs and conventional-PMOS transistors and the other one using the combination of p-type CNT-FETs and conventional-NMOS transistors. The design is based on 45 nm technology node. The proposed structures show a significant improvement in performance in comparison to the conventional one. An increase of 72.44% in DC voltage gain and ~22% decrease in average power is observed in the proposed n-CNT-FET-PMOS-OTA in comparison to CMOS counterpart. Further, the performance can be improved further by using an optimized number of nanotubes in the CNT-FETs used.