High Stability Adaptive LDO using Dynamic Load Sensing for Low Power Management of Wireless Sensor Networks

Presented in this paper is the design of a low-dropout voltage regulator implemented in 65nm CMOS technology for low power management of wireless sensor networks for IoT technology. High stability is achieved using a dynamic load sensing technique where the sensed load current adjusts the bias of the error amplifier. The dynamic mechanism provides low/high bias current to the error amplifier as the load current decreases/increases, respectively. The LDO adapts and transforms from a 2-stage configuration at light-loads to a 3-stage configuration at high-load conditions for a more current-efficient system. Two power transistors are activated depending on the load conditions, with the main power transistor activated only if the load current is greater than the threshold current I
_on
of 919.11μA, allowing for wide range of load application from 0 to 100 mA. Simulation results confirm that adaptive biasing technique through dynamic load sensing and subthreshold operation of the system enables the LDO to achieve ultra-low quiescent current of 930.21nA with power consumption of 744.17nW at no-load. A regulated output voltage of 600mV from 800mV to 1.2V supply voltage with a dropout voltage of 135mV.