A 13.5-nA Quiescent Current LDO With Adaptive Ultra-Low-Power Mode for Low-Power IoT Applications

This brief presents a low-dropout regulator (LDO) for power-efficient Internet of Things (IoT) devices. When IoT devices are in low-power standby mode, the proposed LDO senses the load current and enters an ultra-low-power mode to enable an extremely low-power system. The proposed LDO alternates between two modes of operation. One is the ultra-low-power mode in which the core circuit of the LDO is turned off to save power, and the other is an active mode in which all circuit components are on. The successful operation of the proposed scheme is demonstrated by implementing and measuring silicon LDO chips, resulting in an extremely low-quiescent current of 13.5 nA and a superior figure-of-merit (FOM).