A 0.2V-to-5V fully-integrated reconfigurable buck/boost switched-capacitor voltage regulator for self-powered wireless sensors

Abstract

This paper presents a wide-input, fully-integrated switched-capacitor voltage regulator with multiple conversion ratios (CRs) for self-powered wireless sensors. To reduce design complexity, the paper proposes to design a standard unit cell as the fundamental element to construct step-down or step-up voltage conversions flexibly. Detailed power loss breakdown of the unit cell assists to optimize power devices for high efficiency. Employing only 3 unit cells, a prototype design achieves 11 step-down and 10 step-up voltage conversions for an input voltage range from 0.2V to 5V. A simple single-bound hysteretic control is employed to regulate the output voltage at 1.2V. The proposed switched-capacitor voltage regulator supports the maximum load current of 10mA and achieves a peak efficiency of 80.5%.