A Novel Design of Flip-Flop Circuits using Quantum Dot Cellular Automata(QCA)
Abstract
As the device dimension is shrinking day by day the conventional transistor based CMOS technology encounters serious hindrances due to the physical barriers of the technology such as ultra-thin gate oxides, short channel effects, leakage currents & excessive power dissipation at nano scale regimes. Quantum Dot Cellular Automata is an alternate challenging quantum phenomenon that provides a completely different computational platform to design digital logic circuits using quantum dots confined in the potential well to effectively process and transfer information at nano level as a competitor of traditional CMOS based technology. This paper has demonstrated the implementation of circuits like D, T and JK flip flops using a derived expression from SR flip-flop. The kink energy and energy dissipations has been calculated to determine the robustness of the designed flip-flops. The simulation results have been verified using QCA Designer simulation tool.
Existing System
? CMOS technology is one of the most popular technology in the computer chip design industry and broadly used today to form integrated circuits in numerous and varied applications. ? This technology makes use of both P channel and N channel semiconductor devices. ? One of the most popular MOSFET technologies available today is the Complementary MOS or CMOS technology. ? This is the dominant semiconductor technology for microprocessors, microcontroller chips, memories like RAM, ROM, EEPROM and application specific integrated circuits (ASICs).
Disadvantages
? The conventional CMOS technology faces serious challenging problems due to the physical limitations in its feature size reduction. ? To avoid the input and output lagging problem, we generally use clock signal to add delay. ? In CMOS the serious effects due to physical barriers such as short channel effect , leakage current and excessive power dissipation at nano scale regions. ? One possible alternative method is QCA to overcome this problem. QCA technology transfer’s information by means of polarization using the flow of electrical current.
Proposed System
• In this paper, we proposed the optimized QCA JK flip flops, which require minimum area, number of cells and clock phases. • We propose a dual edge triggered Flip-flops based 4-bit up counter. • QCA is a novel emerging technology in which logic states are not stored as voltage levels, but rather the position of individual electrons. • The QCA cell in contrast to electronics based on transistors, QCA does not operate by the transport of electrons, but by the adjustment of electrons in a small limited area of only a few square nanometers. • QCA is implemented by quadratic cells, the so-called QCA cells.
Advantages
? The scaling of CMOS devices at nano scale affects the performance of several factors like heat dissipation and leakage currents. ? The advantages of QCA over conventional CMOS technology include lesser delay, high density circuits and low power consumption which permits us to perform quantum computing in near future. ? In this paper, novel efficient designs for QCA JK flip flop without wire-crossing are presented. ? In this paper, novel efficient designs for QCA JK flip flop without wirecrossing are presented, which are optimized in terms of cell count, area, power and delay. ? It is clear that the QCA designs are more efficient in terms of area, power and delay in comparison with CMOS technology.
