A Temperature-Adaptive Low Dropout Regulator Architecture with Dynamic Voltage Scaling for Low Power IoT Applications

The aggressive scaling of CMOS technologies for Internet of Things (IoT) devices has intensified power management challenges, particularly under thermally stressed and battery-constrained conditions. Elevated temperatures exacerbate leakage and quiescent currents due to reduced gate oxide thickness and increased subthreshold conduction, severely degrading efficiency and system reliability. This work presents a temperature-adaptive Low Dropout (LDO) regulator architecture specifically designed for ultra-low power IoT applications. In contrast to conventional fixed-reference LDOs, the proposed design dynamically adjusts its output voltage based on die temperature using a composite temperature-sensitive reference, synthesized by combining a process-tunable bandgap reference with a Complementary-To-Absolute-Temperature (CTAT) voltage. The designed regulator supports dual-mode operation, providing 1.8 V and 1.2 V from a 2–3.3 V battery supply. The proposed architecture has been simulated and verified using the 45 nm Cadence technology node. Simulation results confirm its temperature-dependent performance, demonstrating a smooth voltage drop from 1.99 V at -40 °C to 1.65 V at 125 °C under a nominal 1.8 V supply. For a nominal 1.2 V output, the voltage scales from 1.27 V to 0.93 V, with 1.13 V at 25 °C. These results substantially outperform conventional fixed-reference LDOs. The proposed architecture is highly relevant for modern IoT edge devices, wearables that demand ultra-low power operation, extended battery life, and consistent performance in thermally dynamic environments.