Compact Micro scale Multi- Source (Solar and Thermal) Energy harvesting IC with regulated Multi load Power Management scheme

Power is required for all man-made systems to work and perform their corresponding activi-ties.Generation of power in large scale is carried out from power grids and supplied to systems that need high power whereas systems requiring less power are supplied from batteries. Batteries need to be replaced after their lifetime which seem to be a less attractive option in applications where systems are placed out of reach for humans as WSN nodes or in some of biomedical systems which are kept inside human body. The need for a self-supporting system i.e. a system that produces energy by itself and supports all the modules by powering them by itself is increased. A harvesting system that harvests energy from the ambience and converting that energy into electrical form and supplying the power to loads or storing in a battery is the solution for all the problems mentioned above. Solar, thermal, vibration and RF are the sources in the ambience from which energy can be harvested and supplied to load or charged into a battery. Availability of a single energy source(thermal,vibration,solar,RF) at all instances cannot be guaranteed creating a situation of insufficient supply of power to loads or unable to charge the load capacitor to the required voltage. Usage of multiple sources for harvesting energy is a prominent solution to the above mentioned problem. Designing a microscale energy harvesting from multiple sources is the main motto behind the current work.TEG and piezo are compatible to be used alternatively in the system because of their close resemblance in their energy densities. Therefore TEG and piezo have been used as two input sources for the system. The other modules in the system include design of a buck boost power converter that switches between buck and boost modes depending on the source connected to the system and the input voltage available at the input. The other module being a digital controller that generates clocks for power switches, signals that decide if TEG or PV need to be connected to the system.Intra source selection block for TEG array where multiple TEG sources switch between series or parallel depending on the voltage available across each TEG source so as to increase the net power from the TEG. The load is a capacitor that needs to be charged to 1.8V where the system stops working once the capacitor gets charged to the desired voltage. Idea of sharing a single inductor between two different sources without using two power converters for individual sources is implemented. Using the dead time of inductor current of TEG for PV source is the main thought behind the development of the current system. System is designed considering all the specifications, constraints, functionality