A fault tolerant CSA in QCA technology for IoT devices

Area of Science:

• Nanoelectronics
• Quantum Computing
• Fault-Tolerant Systems

Background:

• Internet of Things (IoT) devices require high-performance, low-power circuits.
• Quantum-dot Cellular Automata (QCA) offers nanoscale digital design advantages over CMOS.
• QCA circuits are susceptible to manufacturing and environmental faults, degrading performance.

Purpose of the Study:

• To present a fault-tolerant Carry Skip Adder (CSA) specifically designed for QCA circuits.
• To enhance the reliability of arithmetic components in IoT nodes for signal processing and data manipulation.
• To address the critical need for fault tolerance in QCA-based systems for continuous operation.

Main Methods:

• Designed a fault-tolerant full-adder core (0.06 μm², 0.75 clock cycle) for the CSA.
• Implemented fault-tolerant multiplexers (MUX) and a majority gate resilient to single-cell faults.
• Developed a three-layer CSA architecture comprising 1542 quantum cells and 4.75 clock phases.

Main Results:

• The proposed QCA-based CSA exhibits an 85% tolerance to various failure types.
• The compact CSA architecture occupies an area of 4.59 μm², suitable for area-constrained IoT applications.
• The design integrates fault tolerance directly, ensuring functionality in fault-prone environments.

Conclusions:

• The fault-tolerant CSA enhances the robustness and reliability of QCA digital circuits.
• This architecture is highly suitable for IoT applications demanding power efficiency and minimal area.
• The proposed design enables QCA circuitry to maintain functionality despite inherent fault susceptibility.