Ultra Low Power Conversion Circuit For Batteryless Applications
Energy harvesting is generally seen to be the key to power cyber-physical systems in a low-cost, long term, efficient manner. However, harvesting has traditionally been coupled with large energy storage devices to mitigate the effects of the source's variability. The emerging class of transient, or batteryless, systems avoids this issue by performing computation only as a function of the harvested energy, minimizing the expensive and obtrusive storage element. One of the biggest challenges in batteryless system design is the cold start phase, where the harvesting circuit needs to self-start from 0V with the least amount of energy possible.
While commercially available harvesters, based on boost-buck converters, can operate very efficiently in the >10 uW input power range, they are unable to operate in the nanowatt range. In this project, we want to design a DC-DC converter optimized for very low input power requirements, based on discrete components. The student will start making a caratterizzation of novel small form factor SMD or flexible solar panel and the conversion circuit that is more suitable for the operating points of these solar panel. Afterward a PCB will be desinged and tested in lab to evalute the efficiency performance achieved. As the storage as a important part on the overal efficiency, both supercap and thin-film storage will be evaluated to select the one with the most energy efficiency and low leakage current. Finally a full system which include the energy harvesting and a sensor (a ultra low power camera or other sensor) will be builded and evaluated in the field.
Depending on the applicant's profile and project type, his tasks may involve some of the following:
- lab. testing/characterization of the initial prototype: measuring efficiency and minimum input power requirements
- printed circuit-board design.
- You should have basic knowledge of electrical circuits and simulators.
- Knowledge about DC-DC converters would be an asset.
- 20% Theory
- 50-60% Implementation
- 30-20% Testing