Low-Power Analog Front-End Design for Energy-Harvesting IoT Sensor Nodes
Keywords:
Analog front-end, Energy harvesting, Temperature sensor, Resistive interface, Low power, IoT nodeAbstract
Energy-harvesting Internet-of-Things sensor nodes impose severe constraints on analog front-end circuits, requiring microwatt-level power consumption, wide dynamic range, and robust operation across industrial temperature extremes. This work presents a low-power analog front-end architecture that integrates three complementary design strategies: a compact temperature-sensing channel with sub-degree accuracy, a fully dynamic dual-mode resistive interface with high linearity, and a self-calibrating gain mechanism that eliminates backend nonlinearity correction. The proposed front-end employs a duty-cycled biasing scheme, a switched-capacitor programmable gain stage, and a digital-assisted offset compensation loop. Fabricated in a standard complementary metal-oxide-semiconductor process, the prototype occupies a small active area and consumes only a few microwatts in continuous conversion mode. Measurement results demonstrate a temperature inaccuracy within a narrow band over the industrial range, a dynamic range exceeding one hundred decibels for resistive sensing, and a gain error below one percent without any post-processing correction. The front-end also achieves a power efficiency figure of merit that compares favorably with state-of-the-art designs. The combination of high accuracy, wide dynamic range, and minimal silicon footprint makes the proposed architecture suitable for self-powered environmental and industrial monitoring nodes. The design methodology and measured performance establish a practical pathway for integrating multiple sensing modalities into a single energy-autonomous platform.References
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