Design And Research Of Low Voltage Self-startup Boost Converter For Energy Harvesting Systems

With the development and progress of wireless sensor networks, portable devices and wearable devices, the collection and utilization of micro power waste energy has attracted more and more attention. Meanwhile, energy harvesting and development is also an important research topic in the future development of green energy.This paper proposed a low voltage self-startup boost converter structure based on transformer reuse, achieving self-startup function in the case of very low input voltage. At the same time, in order to achieve low power consumption and high conversion efficiency,the converter we designed also has the maximum power point tracking function, so that the converter has always been power supply to the follow-up equipment with the maximum power.The minmum working voltage of the proposed self-startup circuit is 55mV with oscillation through a positive feedback loop formed by a native MOS and transformer.The oscillation autonomously starts up by thermal nosie and Vout is charged up to 1.3V. When the input voltage is equal to the external reference voltage, the transformer for start-up is reused as an inductor, and the normal boost converter mode with the maximum power point tracking module is enabled for better energy transfer and low-power.The chip is designed and simulated in SMIC 0.18um CMOS process. The simulation results show that the converter can start up at a low input voltage of 55mV-300mV, and it can provide a stable 2V output voltage and a maximum outpur power of 2.1mW. The maximum conversion efficiency of the system is 60% when the input voltage is 300mV.Thus the low power high efficiency converter is achieved, which meets the design expectations.