Energy efficient design of unbalanced ternary logic gates and arithmetic circuits using CNTFET

Abstract

The emergence of multi-valued logic (MVL) is a substitute to binary logic approaches for realizing high-information density logic systems and high-operating speed systems. In this paper, a design for standard ternary inverter (STI), ternary NAND (TNAND), ternary NOR (TNOR) using carbon nanotube field effect transistors (CNTFETs) is proposed in which a p-type dynamic diode is used with the goal of lowering the energy consumption expressed as power delay product (PDP) and thereby reducing battery usage. Additionally, the basic arithmetic operations are then performed using proposed ternary logic circuits, which can be extended to realize more complex operations. The proposed designs are simulated in HSPICE using a 32 nm Stanford CNTFET model. With respect to variation in process parameters, the reliability of the proposed STI circuit is examined. Simulation results verify that the proposed designs show improvement in terms of power consumption and power delay product (PDP) compared to the other CNTFET based ternary logic circuits. Moreover, less variations are observed in power and PDP of the proposed logic gates with variation in process parameters, capacitance, temperature, frequency and supply voltage. The proposed circuit designs of STI, TNAND, TNOR, ternary half adder (THA), ternary multiplier (TMUL) show 78 %, 98 %, 99 %, 99 %, 99 % improvement in PDP respectively, as compared to the conventional CNTFET based circuit designs and 99 % PDP improvement in all proposed circuits compared to CNTFET based logic circuits with resistive load.