Sustainability Benchmark of Subthreshold Level Shifters for IoT Applications
Abhishek Jain, Anuj Grover · 2025
The advancement of semiconductor technology has intensified the demand for ultra-low-power ICs, especially in energy-constrained IoT applications. With continued scaling, the subthreshold operation has become a promising approach for minimizing power consumption. In advanced SoCs utilizing dynamic voltage and frequency scaling (DVFS), Level Shifters are essential for interfacing domains operating at different voltage levels. When one of the voltage islands functions at a sub-threshold voltage, specialized Subthreshold Level Shifters (SLS) are employed to ensure reliable signal transition. Various SLS architectures are available in the industry, each evaluated based on conventional PPA (Power, Performance, and Area) metrics to determine their suitability for different applications. Beyond PPA, the integration of a sustainability evaluation paradigm broadens the analysis by assessing the fabrication and operational impact of a design, ensuring long-term efficiency and a reduced carbon footprint. In this work, a set of SLS architectures has been benchmarked using a novel sustainability-focused evaluation paradigm in 65nm Low Standby Power technology. This bench-mark paradigm enables designers to choose the most efficient and sustainable SLS architecture among the available ones.