Optimizing the ratio of number of tubes in PCNTFET to NCNTFET for digital circuits

Abhinav Bhansali

Dr. Abhijit Asati

Carbon Nanotube Field Effect Transistors (CNTFET) offer various benefits as compared to other FETs. Many circuits can be constructed using PCNTFETs (P-type CNTFETs) and NCNTFETs (N-type CNTFETs) like the PMOS and NMOS of the Complementary Metal Oxide Semiconductors (CMOS) technology. The CNTFETs employ carbon nanotubes in the channel of the device to provide a path for the ballistic conduction of electrons. The different ratios of the number of tubes in the channel of the PCNTFET to the number of tubes in the channel of the NCNTFET lead to different properties of the device. This paper focuses on determining that ratio of the number of tubes in the PCNTFET to the NCNTFET which gives minimum Power Delay Product (PDP) by analysing a circuit in which an inverter is loaded with 8 inverters. Using the results, a 4×4 Baugh-Wooley multiplier is constructed and its performance is compared with that of a multiplier constructed in a different way.