AC-Logic Family for Smart Dust and IoT Applications

Ultra-low power consumption and efficient nano-energy harvesting are critical requirements to prolong the lifetime of the IoT motes. In this work, an AC logic family was developed, which, unlike the conventional logic unit, provides logic information in phase instead of the amplitude of the signal. The AC sinusoid signals are directly applied to the AC logic unit, thus, eliminating the rectifier and storage capacitor, which significantly improves the overall system’s power efficiency. In the proposed approach, AC sinusoids are used as power source and as data inputs to the logic cells. The proposed design is suitable for ultra-low power smart dust IoT sensors operating in the µW to mW regime. In the proposed design, NOT, NAND, and NOR gates consume 8.2 nW, 16 nW, and 20.8 nW respectively and a 3-bit adder consumes 15 µW of power in simulations, while operating at 100 MHz. The design is simulated and taped out using a 65 nm bulk CMOS process. The die is packaged using CLCC 68 pins and measurements are carried out to verify the functionality of the proposed logic gates.