Novel Design of BCD to Excess-3 Code Converter in Quantum Dots Cellular Automata(QCA)
Quantum-dot cellular automata (QCA) represent a new technology at the nanotechnology level. Conventional digital technologies use ranges of voltage or current to represent binary values. In contrast, QCA uses the positions of electrons in quantum dots to represent binary Values ‘0’ and ‘1’. Quantum technology has gradually applied in various fields. A quantum-dot cellular automaton is projected as a promising nanotechnology for future ICs. A QCA is an array of structures known as quantum-dots. The advantages of using QCA technology are smaller circuit size, higher clock frequency, and lower power consumption. Two electrons occupy each cell. Each electron is free to tunnel between dots within one cell, but cannot leave the cell. The two electrons within each cell repel each other to diagonally opposite corners of the cell. This leaves only two stable states for each cell. These two states are used to represent logic values. The occupation of upper-left and lower-right dots represent logic ‘0’. In this case, the QCA cell is said to be polarized to -1. Similarly, the occupation of upper-right and lower left dots represent logic ‘1’. In this case, the QCA cell is said to be polarized to +1. In this paper, a BCD to excess-3 code converter circuit is proposed based on QCA logic gates: the 3-input MV OR gate, 3-input MV AND gate, MV NOT gate. This 3-input AND & 3-input OR gates, 3-input complex gates, multi-input complex gates. The proposed circuit is a remising future in constructing of nano-scale low power consumption information processing system and can stimulate higher digital applications in QCA.
