A Novel Carbon Nanotube Field Effect Transistors Based Triple Cascode Operational Transconductance Amplifier: An Optimum Design

This paper discusses a triple-cascode operational transconductance amplifier (TCOTA) circuit’s design and modeling. These proposed TCOTAs are constructed using 45 nm Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) and Carbon Nanotube Field Effect Transistors (CNTFETs). At the 45 nm technology node, three distinct varieties of CNT-based TCOTAs have been designed and contrasted with conventional CMOS-based TCOTAs. The performance of the CNT-based TCOTAs, particularly a pure CNT-TCOTA, has significantly improved, according to the assessment of the fundamental aspects of all the devices. The DC gain has been enhanced by 73% when contrasting the pure CNT-TCOTA to the conventional CMOS-TCOTA, the CMRR has improved by 28%, and the power consumption has been reduced by 100.63%. Furthermore, in pure CNT-TCOTA, (FOM)₁ and (FOM)₂ have increased by 194% and 173%, respectively. It has also been investigated thoroughly how CNT-based OTAs perform by adjusting the CNT diameter (DCNT), pitch (S), and number of CNTs (N) at CL = 0.01 pF and 0.9 V power supply. It has been determined that using optimum CNT quantity, the pitch between CNTs, and diameter values can further enhance their performance. The simulation and comparative studies of all circuit structures have reported that novel and remarkable improvement is distinguished in CNT-based TCOTA. According to simulation and comparative assessments of all circuit structures, CNT-based TCOTA exhibits a novel and noteworthy improvement. Moreover, when compared to the conventional CMOS-TCOTA, the pure CNT-TCOTA has shown significant enhancement of 11.1% and 10.24% in GM and PM, respectively. Pure CNT-TCOTA has been demonstrated to be highly stable by the stability analysis.