An n-FET-only IGZO low-dropout regulator evaluated under practical power-management conditions

Power-management circuits remain underdeveloped in flexible electronics, limiting autonomous sensing and control systems. Thin-film transistor low-dropout (LDO) regulators have demonstrated voltage regulation beyond silicon, but standalone metrics alone do not show whether foundry-enabled IGZO regulators can support practical low-power rails. We report an n-FET-only IGZO low-dropout regulator evaluated as a power-management block, not only as a standalone circuit. The regulator operates from a 3.3 V rail with quiescent current close to 1 µA and provides reference-set local regulation for low-power sensing electronics. The measurements show three relevant limits for practical use: chip-to-chip output-voltage variability, with standard deviation of approximately 98–125 mV across the load range, simulation-to-measurement discrepancies under headroom-limited operation, and output-voltage drift during 24 h fixed-bias operation. Finally, the fabricated regulator replaced a commercial LDO in one solar-powered sensing node, achieving a similar operating time, while the output drift limits its use as a general-purpose replacement.