Design of Novel Inverter and Buffer in Quantum-dot Cellular Automata (QCA)

Quantum-dot Cellular Automata (QCA) is an emerging nanotechnology to reduce size as well as power consumption of switching devices for Very Large Integrated Circuits (VLSI). Moreover QCA circuits offer an advantage of very high device density, high speed, high fan out, and lower circuit complexity. The QCA based circuits have been used for implementations of basic logic gates like AND, OR, NOT as well as XOR/XNOR gates. This paper aims at the design of a programmable inverter/buffer using proposed XOR gate. The proposed circuit can be used as an inverter (NOT gate) or a buffer (pass gate). The programmable inverter/buffer has been designed and simulated based on intensive discrete arithmetic analysis. In addition, 2-bit and 3-bit programmable inverter/buffer has also been designed and implemented in this paper. The proposed design enjoys the features of small area, superior performance factors in respect of speed and circuit stability. The simulation results have been verified using QCADesigner tool version 2.0.3.