Design Consideration of Self-Oscillating Voltage booster Including JFET Characteristics for Energy Harvesting Applications

An Energy Harvesting (E.H.) has been paid attention for the field of Internet of Things (IoT) in recent years. The wireless sensor as a key component of IoT can be realized battery less operation by using E.H technology. The oscillating circuit with a step-up transformer is used as a voltage booster for E.H. The voltage booster has not been fully analyzed the influences of the circuit parameters yet. In this paper, the influence of JFET parameters such as parasitic capacitance and threshold voltage are analyzed, and the self-oscillating voltage booster is designed including the JFET parameters. As a result, it is clarified that the large additional capacitance connected into gate-source terminal of JFET can be remarkably reduced the influence of input capacitance of JFET. Moreover, the relationship between threshold voltage and amplitude condition are clarified. Finally, the validity of the analysis and design method are experimentally confirmed.