微功率能量收集系统中片上集成的超低压自启动方法研究

项目名称： 微功率能量收集系统中片上集成的超低压自启动方法研究

项目编号： No.61504109

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 无线电电子学、电信技术

项目作者： 马彦昭

作者单位： 西北工业大学

项目金额： 20万元

中文摘要： 微功率能量收集系统在可穿戴设备、植入式医疗电子、无线传感器网络等低功耗电子设备中能够替代电池实现自给供电。微功率能量收集器的输出功率小、电压低，无法采用传统的电源管理电路进行电压调整，需要一种自启动机制。本项目针对微功率能量收集系统面临的超低压自启动问题，研究功率损耗和启动方法对启动电压的影响，揭示限制最低启动电压的关键因素，探索降低最低启动电压的方法。为了减小功率损耗，采用阈值电压补偿或增加过驱动电压的方法减小导通损耗，采用衬底动态偏置或增大器件的栅源反向电压的方法减小漏电流损耗。在启动方法上，直流输入的启动电路采用增大摆幅的LC振荡器与电压倍增器级联的方案，交流输入的启动电路采用桥式整流器与电荷泵级联的方案。为了避免系统锁定，提出了一种对输入电压和负载电流进行动态启动检测的方法。本项目预期的方案具有低压低功耗和易于片上集成的特点，研究成果对于微功率能量收集系统的低功耗应用具有重要意义。

中文关键词： 能量收集；电源管理集成电路；超低压自启动方法；超低功耗电路；亚阈值电路

英文摘要： The micro-power energy harvesting system is possible to power the low-power devices instead of battery, such as wearable device, implantable medical devices， and wireless sensor network. The output of micro-power energy harvester is low-power and low-voltage, and it is not possible to regulate by the conventional power management. The ultra-low voltage self-start method is crucial for micro-power energy harvesting system. The proposal is aimed to solve the problem by analyzing the startup voltage under the influence of power loss and startup method, disclosing the chief factor of limiting the minimum startup voltage, and investigating the method to reduce the minimum startup voltage. The conduction loss is reduced by adopting threshold voltage compensation method or increasing the overdrive voltage, and the leakage current is reduced by adopting dynamic body biasing method or increasing the reverse gate-drain voltage. The method by cascading enhanced swing LC oscillator and voltage multiplier is proposed for startup of the energy harvester with dc output. The method by cascading bridge rectifier and charge pump is proposed for startup of the energy harvester with ac output. A method by dynamic detecting the input voltage and load current is proposed to avoid system lockup. The expected solution would be low-voltage, low-power and suitable for on-chip implementation. Furthermore, these theories are crucial to micro-power energy harvesting for low-power application.

英文关键词： Energy harvesting;Intergrated power management circuits;Ultra-low voltage self-start methods;Ultra-low power circuits;Subthreshold circuits