Design Of Power Management ASIC For Triboelectric Nanogenerators

The self-powered environmental energy harvesting system can offer a new power supply schema for wireless sensor nodes(WSNs) and wearable devices. This system has made a breakthrough about the battery life and maintenance. In recent years, a novel triboelectric nanogenerator(TENG) energy harvester has been developed. The power density has been raised up greatly and optimized. However, the research about the energy management circuit for TENG is not enough. The TENG energy harvester has a high voltage, low current and high impedance output characteristic. The output is capacitance alternative current. On the other side, the TENG energy harvest has a great out power compared with other energy harvesters. This characteristic has made its energy management circuit very difficult to realize. Currently, the TENG energy management circuits are based on independent devices and PCB circuits. The energy management circuits have consumed much energy. Therefore, this paper designs an ASIC(Applied Specific Integrated Circuits) to manage energy of TENG. This ASIC circuit consumes much lower power and is more purposeful and customizable.This paper firstly analyzes and compares the characteristics and output performances of different TENGs, such as the first order equivalent circuit model. This paper also makes a summary of TENGs’ electrical output characteristic. It focuses on the research of impedance matching, maximum power transfer and optimal load matching, then raises a optimization about TENG power management’s load switching method and charging management method. Based on the theory research, this paper raises a real impedance matching circuit, rectifier and optimized electric energy harvesting plan. The energy management circuit for TENG has been raised up in this paper. Then based on this energy management circuit, the thesis designs a power conditioning circuit. Taken the ASIC design method, the voltage feedback PWM(Pulse Width Modulation) regulating DC-DC(Direct Current to Direct Current) method has been used in the power condition circuit. This circuit mainly contains the low-power reference circuit, low-power in-chip relaxation oscillation circuit, low-power amplifier, low-power UVLO(Under Voltage Lock) circuit, low-power PWM comparator and high performance power switch transistor. This chip uses CSMC 0.18 um 1P6M CMOS process. These circuits are simulated and analyzed carefully based on EDA software in this paper. Finally, the total work current of the ASIC is about 5uA. The low power consumption has been realized.