QCA-Based Pulse/Bit Sequence Detector Using Low Quantum Cost D-Flip Flop

Abstract

In this paper, a Quantum-Dot Cellular Automata (QCA)-based [Formula: see text]-flip flop is designed with low quantum cost to propose a 3-bit sequence detector which detects a bit pattern 101 in both overlapping and non-overlapping forms. Initially, a level to edge-triggered clock converter is proposed to convert clock signal levels into edge defining signals. Later, [Formula: see text]-flip flops of both level and edge triggered clock inputs are developed. Compared with the recently reported designs in the literature, it is observed that the quantum cost of the proposed [Formula: see text]-flip flops is decreased by more than 28% with a cell count of 34, which in turn defines the low area too. Also, latency of the same is reduced by one-fourth with a value of [Formula: see text] s. As far as the sequence detector is concerned, it is smaller in size at 0.16[Formula: see text][Formula: see text]m2 than the existing sequential circuits with a reduction in area and quantum cost by 30%. Further, from the bit stream it detects, the proposed sequence detector can also be used as negative pulse detector and interrupt handler circuit in the future QCA-based digital systems to detect the external interrupts.