A high DC accuracy, nano-ampere output-capacitor-less LDO with embedded voltage reference and multi-loop regulation scheme

This paper presents a 0.9-1.5 V output-capacitor-less low-dropout (LDO) regulator designed to break the tradeoff between ultra-low power consumption and high DC accuracy for compact Internet of Things (IoT) applications. By leveraging a hybrid biasing scheme combined with a multi-loop regulation architecture, the proposed LDO achieves a 10 nA-10 mA range while maintaining robust stability. An embedded CMOS voltage reference (VR) is integrated with a body-trimming mechanism to ensure robustness against PVT variations, yielding a temperature coefficient (TC) of 14.8 ppm/°C from -40 °C to 125 °C. The circuit is implemented in TSMC 180-nm CMOS process, occupying 0.074 mm2 with a quiescent current of 265 nA. Measurement results demonstrate superior regulation performance with a line regulation of 0.29 mV/V and a load regulation of 0.11 mV/mA. For a full-scale 10 mA load transient with a 10 ns edge time, the regulator exhibits a 444.5 mV undershoot, proving its capability to handle highly dynamic loads in battery-powered systems.