The Design Of DC-AC-DC Booster Circuit Applied To Tiny Environment Energy Collection

The micro wireless sensors are the nerve endings of the future internet of things era, it will be everywhere and pass the information of perceive the world to information processing center continuously. However, in many cases,it is not feasible to power micro wireless sensors with batteries or ac powers, because the energy of the batteries will run out to a certain service life, it is almost impossible to replace batteries in many cases and ac powers are not widely available.So, a new integrated circuit and micro-electro-mechanical cross technology about energy harvesting begin to get the attention of people. The technology of environmental energy power generation appears early, such as hydroelectric power and solar power generation that used in our daily life. But usually the environmental energy power generation that we say refers to the tiny environment energy collection.However the energy get from small environment is so small, in general get dozens to hundreds of microwatt orders of magnitude, but the power consumption of traditional integrated circuit is above milliwatts orders of magnitude, so if want to use the collected energy to power integrated circuit,we must put forward a new circuit structure.The design of DC-AC-DC boost circuit in this paper is composed by DC-AC inverter and AC-DC active rectifier circuit two parts. DC-AC inverter is composed by transformer and depletion MOSFET, using the electromagnetic induction principle to implement since the launch, using the conversion between can the electric field and magnetic field energy to implement the self-excited oscillation, thus to get the ac on the output side that we need. We use PMOSFET controlled by comparator instead of common PN junction diode in AC-DC active rectifier circuit, thus reducing the voltage drop of the circuit, improve the efficiency of the rectifier.This DC-AC-DC boost circuit system has been implemented in a 0.5um CMOS technology and simulated by the analog integrated circuit simulation tools. The simulation results show that the minimum start-up voltage of the system is 30 m V, the energy conversion efficiency above 45%, when the input voltage is 100 m V, the static power of the circuit less than 250 uW.