This study presents new low‐power multiple‐valued logic (MVL) circuits for nanoelectronics. These carbon nanotube field effect transistor (FET) (CNTFET)‐based MVL circuits are designed based on the unique characteristics of the CNTFET device such as the capability of setting the desired threshold voltages by adopting correct diameters for the nanotubes as well as the same carrier mobility for the P‐ and N‐type devices. These characteristics make CNTFETs very suitable for designing high‐performance multiple‐ V th circuits. The proposed MVL circuits are designed based on the conventional CMOS architecture and by utilising inherently binary gates. Moreover, each of the proposed CNTFET‐based ternary circuits includes all the possible types of ternary logic, that is, negative, positive and standard, in one structure. The method proposed in this study is a universal technique for designing MVL logic circuits with any arbitrary number of logic levels, without static power dissipation. The results of the simulations, conducted using Synopsys HSPICE with 32 nm‐CNTFET technology, demonstrate improvements in terms of power consumption, energy efficiency, robustness and specifically static power dissipation with respect to the other state‐of‐the‐art ternary and quaternary circuits.
This article presents a high-speed and high-performance Carbon Nanotube Field Effect Transistor (CNFET) based Full Adder cell for low-voltage applications. The proposed Full Adder cell is composed of two separate modules with identical hardware configurations which generate the Sum and Cout signals in a parallel manner. The great advantage of the proposed structure is its very short critical path which is composed of only two carbon nanotube pass-transistors. This design also takes advantage of the unique properties of metal oxide semiconductor field effect transistor-like CNFETs such as the feasibility of adjusting the threshold voltage of a CNFET by adjusting the diameter of its nanotubes to correct the voltage levels as well as to achieve a high performance. Comprehensive experiments are performed in various situations to evaluate the performance of the proposed design. Simulations are carried out using Synopsys HSPICE with 32-nm Complementary Metal Oxide Semiconductor (CMOS) and 32-nm CNFET technologies. The simulation results demonstrate the superiority of the proposed design in terms of speed, power consumption, power delay product, and less susceptibility to process variations, compared to other classical and modern CMOS and CNFET-based Full Adder cells.
18 March 2010 in International Journal of Electronics
Novel direct designs for 3-input exclusive-OR (XOR) function at transistor level are proposed in this article. These designs are appropriate for low-power and high-speed applications. The critical path of the presented designs consists of only two pass-transistors, which causes low propagation delay. Neither complementary inputs, nor VDD and ground exist in the basic structure of these designs. The proposed designs have low dynamic and short-circuit power consumptions and their internal nodes dissipate negligible leakage power, which leads to low average power consumption. Some effective approaches are presented for improving the performance, voltage levels, and the driving capability and lowering the number of transistors of the basic structure of the designs. All of the proposed designs and several classical and state-of-the-art 3-input XOR circuits are simulated in a realistic condition using HSPICE with 90 nm CMOS technology at six supply voltages, ranging from 1.3 V down to 0.8 V. The simulation results demonstrate that the proposed circuits are superior in terms of speed, power consumption and power-delay product (PDP) with respect to other designs.
1 June 2011 in Journal of Circuits, Systems and Computers