In present work, improved designs for voltage controlled ring oscillators (VCO) using three transistors XNOR/XOR gates have been presented. Supply voltage has been varied from [1.8 - 1.2] V in proposed designs. In fir...In present work, improved designs for voltage controlled ring oscillators (VCO) using three transistors XNOR/XOR gates have been presented. Supply voltage has been varied from [1.8 - 1.2] V in proposed designs. In first method, the VCO design using three XNOR delay cells shows frequency variation of [1.900 - 0.964] GHz with [279.429 - 16.515] μW power consumption variation. VCO designed with five XNOR delay cells shows frequency variation of [1.152 - 0.575] GHz with varying power consumption of [465.715 - 27.526] μW. In the second method VCO having three XOR stages shows frequency variation [1.9176 - 1.029] GHz with power consumption variation from [296.393 - 19.051] μW. A five stage XOR based VCO design shows frequency variation [1.049 - 0.565] GHz with power consumption variation from [493.989 - 31.753] μW. Simulations have been performed by using SPICE based on TSMC 0.18μm CMOS technology. Power consumption and output frequency range of proposed VCOs have been compared with earlier reported circuits and proposed circuit’s shows improved performance.展开更多
To fill the continuous needs for faster processing elements with less power consumption causes large pressure on the complementary metal oxide semiconductor(CMOS)technology developers.The scaling scenario is not an op...To fill the continuous needs for faster processing elements with less power consumption causes large pressure on the complementary metal oxide semiconductor(CMOS)technology developers.The scaling scenario is not an option nowadays and other technologies need to be investigated.The quantum-dot cellular automata(QCA)technology is one of the important emerging nanotechnologies that have attracted much researchers’attention in recent years.This technology has many interesting features,such as high speed,low power consumption,and small size.These features make it an appropriate alternative to the CMOS technique.This paper suggests three novel structures of XNOR gates in the QCA technology.The presented structures do not follow the conventional approaches to the logic gates design but depend on the inherent capabilities of the new technology.The proposed structures are used as the main building blocks for a single-bit comparator.The resulted circuits are simulated for the verification purpose and then compared with existing counterparts in the literature.The comparison results are encouraging to append the proposed structures to the library of QCA gates.展开更多
Quantum-dot cellular automaton (QCA) is an emerging, promising, future generation nanoelectronic computational architecture that encodes binary information as electronic charge configuration of a cell. It is a digital...Quantum-dot cellular automaton (QCA) is an emerging, promising, future generation nanoelectronic computational architecture that encodes binary information as electronic charge configuration of a cell. It is a digital logic architecture that uses single electrons in arrays of quantum dots to perform binary operations. Fundamental unit in building of QCA circuits is a QCA cell. A QCA cell is an elementary building block which can be used to build basic gates and logic devices in QCA architectures. This paper evaluates the performance of various implementations of QCA based XOR gates and proposes various novel layouts with better performance parameters. We presented the various QCA circuit design methodology for XOR gate. These layouts show less number of crossovers and lesser cell count as compared to the conventional layouts already present in the literature. These design topologies have special functions in communication based circuit applications. They are particularly useful in phase detectors in digital circuits, arithmetic operations and error detection & correction circuits. The comparison of various circuit designs is also given. The proposed designs can be effectively used to realize more complex circuits. The simulations in the present work have been carried out using QCADesigner tool.展开更多
文摘In present work, improved designs for voltage controlled ring oscillators (VCO) using three transistors XNOR/XOR gates have been presented. Supply voltage has been varied from [1.8 - 1.2] V in proposed designs. In first method, the VCO design using three XNOR delay cells shows frequency variation of [1.900 - 0.964] GHz with [279.429 - 16.515] μW power consumption variation. VCO designed with five XNOR delay cells shows frequency variation of [1.152 - 0.575] GHz with varying power consumption of [465.715 - 27.526] μW. In the second method VCO having three XOR stages shows frequency variation [1.9176 - 1.029] GHz with power consumption variation from [296.393 - 19.051] μW. A five stage XOR based VCO design shows frequency variation [1.049 - 0.565] GHz with power consumption variation from [493.989 - 31.753] μW. Simulations have been performed by using SPICE based on TSMC 0.18μm CMOS technology. Power consumption and output frequency range of proposed VCOs have been compared with earlier reported circuits and proposed circuit’s shows improved performance.
文摘To fill the continuous needs for faster processing elements with less power consumption causes large pressure on the complementary metal oxide semiconductor(CMOS)technology developers.The scaling scenario is not an option nowadays and other technologies need to be investigated.The quantum-dot cellular automata(QCA)technology is one of the important emerging nanotechnologies that have attracted much researchers’attention in recent years.This technology has many interesting features,such as high speed,low power consumption,and small size.These features make it an appropriate alternative to the CMOS technique.This paper suggests three novel structures of XNOR gates in the QCA technology.The presented structures do not follow the conventional approaches to the logic gates design but depend on the inherent capabilities of the new technology.The proposed structures are used as the main building blocks for a single-bit comparator.The resulted circuits are simulated for the verification purpose and then compared with existing counterparts in the literature.The comparison results are encouraging to append the proposed structures to the library of QCA gates.
文摘Quantum-dot cellular automaton (QCA) is an emerging, promising, future generation nanoelectronic computational architecture that encodes binary information as electronic charge configuration of a cell. It is a digital logic architecture that uses single electrons in arrays of quantum dots to perform binary operations. Fundamental unit in building of QCA circuits is a QCA cell. A QCA cell is an elementary building block which can be used to build basic gates and logic devices in QCA architectures. This paper evaluates the performance of various implementations of QCA based XOR gates and proposes various novel layouts with better performance parameters. We presented the various QCA circuit design methodology for XOR gate. These layouts show less number of crossovers and lesser cell count as compared to the conventional layouts already present in the literature. These design topologies have special functions in communication based circuit applications. They are particularly useful in phase detectors in digital circuits, arithmetic operations and error detection & correction circuits. The comparison of various circuit designs is also given. The proposed designs can be effectively used to realize more complex circuits. The simulations in the present work have been carried out using QCADesigner tool.
