A fully-integrated system power aware LDO for energy harvesting applications

A digitally enhanced low dropout regulator (LDO) supplying the digital core of an ultra-low-power MCU is presented. By making use of known system power information the LDO digitally adapts its maximum current drivability up to 2.56mA while its quiescent current is as low as 650nA in light load conditions. In this way, the LDO current efficiency remains above 97% over two decades of load current. Energy required for start-up is minimized by drastically reducing capacitance at the LDO output.