Research And Design Of The System Of Boost DC-DC Converter For Micropower Energy Harvesting

Today,portable devices and wireless sensor networks are widely used.These electronic devices are usually powered by batteries,but in some remote areas,due to the difficulty of battery replacement and maintenance,how to supply power to these devices has become a problem.Therefore,people have paid great attention to the collection and utilization of tiny power energy.It has become possible to use micropower energy in the environment to power these devices.In the energy harvesting system,how to achieve energy harvesting,boosting,and power supply to the load has become this paper research problem.DC-DC converters have become the first choice for energy harvesting systems because of their fast response,low power consumption,and high power efficiency.Therefore,this paper designs a Boost DC-DC converter that can be used for micropower energy harvesting.By analyzing the application background,development history and research status of the energy harvesting system,as well as the analysis of the advantages and disadvantages of the three commonly used DC-DC converters,the characteristics of the power supply module suitable for the energy harvesting system are summarized.Boost DC-DC is used as the topology of the converter,and the peak current feedback mode is used as the control method of the converter.This mode reduces the difficulty of loop compensation and improves the response speed of the system.Aiming at the problem of low output voltage of the energy collector,a startup circuit that can work under low input voltage is proposed.The built-in startup oscillator and charge pump realize ultra-low input voltage startup,and set up auxiliary power tube and auxiliary voltage,speed up the start-up phase.The voltage detection circuit designed at the same time shuts down the startup circuit after the circuit enters the normal working mode,which reduces the power consumption of the system.The maximum power point tracking circuit based on the open-circuit voltage method input sampling proposed in this paper works by dynamically adjusting the inductor current to make the input voltage work at the maximum power point,so that the energy is used to a great extent,and the system always uses the maximum power to the load output energy.In this paper,0.18μm BCD process is used for the design of the micro-power energy harvesting Boost DC-DC converter.The converter can work in an extremely wide input voltage range of 0.4V 5V and an output voltage range of 1.6V 5.25V;When the input voltage is 1V,the system efficiency is up to more than 80%;the system startup characteristics,linear transient and load transient response are stable.