LAUSR

This paper presents a fully-integrated adaptive dual-output power management system with storage capability for thermoelectric energy harvesting applications. The first output delivers the load power and is regulated at 1.6 V. This output is provided by the primary path of the system that is implemented using a 5-stage reconfigurable Dickson charge pump. In case of the presence of more available power than the load demand, a secondary path is enabled to store the excess amount of energy on a supercapacitor. This provides the second output of the system that is capable of charging up to about twice the voltage of the first output. Besides storing the excess energy, a new technique using the secondary path is proposed for regulating the first output and achieving the maximum power point tracking of the input source. The proposed system is automatically reconfigured to maximize the end-to-end efficiency with the aid of a finite state machine. The system is implemented in 180nm CMOS technology. It utilizes a total on-chip flying capacitance of 2.1 nF, and operates across an input voltage range from 0.35 V to 1 V. Measurement results show that the system achieves an end-to-end efficiency of 72% at a total output power of 1.24 mW.