An Optimal Gate Design for the Synthesis of Ternary Logic Circuits

Department of Electrical EngineeringOver the last few decades, CMOS-based digital circuits have been steadily developed. However, because of the power density limits, device scaling may soon come to an end, and new approaches for circuit designs are required. Multi-valued logic (MVL) is one of the new approaches, which increases the radix for computation to lower the complexity of the circuit. For the MVL implementation, ternary logic circuit designs have been proposed previously, though they could not show advantages over binary logic, because of unoptimized synthesis techniques. In this thesis, we propose a methodology to design ternary gates by modeling pull-up and pull-down operations of the gates. Our proposed methodology makes it possible to synthesize ternary gates with a minimum number of transistors. From HSPICE simulation results, our ternary designs show significant power-delay product reductions; 49 % in the ternary full adder and 62 % in the ternary multiplier compared to the existing methodology. We have also compared the number of transistors in CMOS-based binary logic circuits and ternary device-based logic circuits We propose a methodology for using ternary values effectively in sequential logic. Proposed ternary D flip-flop is designed to normally operate in four-edges of a ternary clock signal. A quad-edge-triggered ternary D flip-flop (QETDFF) is designed with static gates using CNTFET. From HSPICE simulation results, we have confirmed that power-delay-product (PDP) of QETDFF is reduced by 82.31 % compared to state of the art ternary D flip-flop. We synthesize a ternary serial adder using QETDFF. PDP of the proposed ternary serial adder is reduced by 98.23 % compared to state of the art design.ope

Novel Ternary Logic Gates Design in Nanoelectronics

In this paper, standard ternary logic gates are initially designed to considerably reduce static power consumption. This study proposes novel ternary gates based on two supply voltages in which the direct current is eliminated and the leakage current is reduced considerably. In addition, ST-OR and ST-AND are generated directly instead of ST-NAND and ST-NOR. The proposed gates have a high noise margin near V_(DD)/4. The simulation results indicated that the power consumption and PDP underwent a~sharp decrease and noise margin showed a considerable increase in comparison to both one supply and two supply based designs in previous works. PDP is improved in the proposed OR, as compared to one supply and two supply based previous works about 83% and 63%, respectively. Also, a memory cell is designed using the proposed STI logic gate, which has a considerably lower static power to store logic ‘1’ and the static noise margin, as compared to other designs

Energy Efficient CNTFET Based Full Adder Using Hybrid Logic

Full Adder is the basic element for arithmetic operations used in Very Large Scale Integrated (VLSI) circuits, therefore, optimization of 1-bit full adder cell improves the overall performance of electronic devices. Due to unique mechanical and electrical characteristics, carbon nanotube field effect transistors (CNTFET) are found to be the most suitable alternative for metal oxide field effect transistor (MOSFET). CNTFET transistor utilizes carbon nanotube (CNT) in the channel region. In this paper, high speed, low power and reduced transistor count full adder cell using CNTFET 32nm technology is presented. Two input full swing XOR gate is designed using 4 transistors which is further used to generate Sum and Carry output signals with the help of Gate-Diffusion-Input (GDI) Technique thus reducing the number of transistors involved. Proposed design simulated in Cadence Virtuoso with 32nm CNTFET technology and results is better design as compared to existing circuits in terms of Power, Delay, Power-Delay-Product (PDP), Energy Consumption and Energy-Delay-Product (EDP)

CNFET-based design ternary logic design and arithmetic circuit simulation using HSPICE

This project report focuses on the multiple-value logic (MVL) or commonly known as ternary logic gates by using carbon nanotube (CNT) FETs devices (CNTFETs). It is shown ternary logic has promising future in CNTFETs when compare to conventional binary logic design, due to its simplicity and energy efficiency in digital design reduced circuit overhead such as chip area and interconnection. In this research, existing CNTFET-based binary inverter and standard ternary inverter with resistive-load (STI-R) for comparison with the other three types of inverter are proposed - Complementary Standard Ternary Inverter (CSTI); Standard Ternary Inverter with 1 resistor and 3 NCNTFET (NSTI-R); Standard Ternary Inverter with 1 resistor and 3 PCNTFET (PSTI-R) to analysis the performance, structure design and application. In addition, the research covers all the basic logic Ternary NAND gate and Ternary NOR gate for further benchmarking. All simulation results using SPICE are obtained and analyzed in the Direct Current (DC) setting and verifed using half adder. Further study behavior of ternary logic includes the implementation of partial binary design into the ternary design and performance benchmarking. The result shows the CSTI have advantage on low power design with low leakage while NSTI-R has advantage on high-speed design inverter. In addition, partial binary design in the arithmetic circuit ternary design with CSTI shows added advantage in a low power design