Performance of Power Converters for Ultra Low Power Systems: A Review

In the new era of Internet of Things (IOT) where 50 billion devices are projected to be linked to the internet, different challenges like system integration, low power design, security are imposed on the semiconductor industry. The rapid increase in the demand for battery-operated IOT devices and the scaling of Complementary Metal Oxide Semiconductor (CMOS) devices has gained the attention of ultra-low power design approaches. Most IOT devices are active for a short amount of time and are in sleep or standby mode for a long time. Systems require different power levels as they combine Intellectual Property from analog, digital and mixed signal vendors thereby necessitating efficient power management circuits. This paper reviews different power converters and energy harvesting systems with low power architectures and circuit level optimizations.