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.
? 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).
? 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.
• 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.
? 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.
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