一個用於壓電能量擷取系統的同步反相和電荷提取介面電路

Abstract

隨著物聯網概念的發展，無線設備被廣泛使用，而為這些設備供電則是一個問題。如果使用電池，我們必須每隔一段時間更換一次電池。此外，廢棄的電池也會造成環境汙染。因此，我們從環境能源中收集能量來延長電池壽命，最終實現無電池IOT設備的目標。在室內，環境的振動源提供最高的功率密度，因此，我們使用壓電能量擷取系統來收集這些能量。 同步電感式能量擷取電路 (SSHI)和同步電荷擷取電路(SECE)是兩種常見的的介面電路。與標準介面電路相比，SSHI具有高功率增益的優點，而功率增益取決於負載阻抗。而SECE具有中等的功率增益，但功率增益完全獨立於負載阻抗。而本論文提出用於壓電能量擷取的同步反相和電荷提取（SICE）介面電路，結合SSHI和SECE電路，在給定的反轉次數下，反轉達到峰值的壓電電壓（偏置翻轉動作），然後通過SECE電路擷取總能量。因此，可以同時獲得高功率增益和負載獨立的優點。 此晶片使用台積電0.25μm HV-CMOS製程來實現。根據量測結果，此介面電路在壓電電壓峰值為10 V且不翻轉的情況，擷取的功率為130μW，此時的功率增益為290%；而在壓電電壓峰值為2.8 V且反轉次數為3時，擷取功率為22μW，此時的功率增益為628%。

With the development of the Internet of Things, wireless devices are widely used, and powering these devices is a problem. If using a battery, we must replace the battery at regular intervals. In addition, discarded batteries can also cause environmental pollution. Therefore, we collect energy from environmental energy to extend battery life and ultimately achieve the goal of battery-free IOT equipment. Indoors, the ambient vibration source provides the highest power density, so we use a piezoelectric energy harvesting system to collect this energy. Synchronized switch harvesting on inductor (SSHI) and synchronous electric charge extraction (SECE) are two common interface circuits. Compared to standard interface circuits, SSHI has the advantage of high power gain, while power gain depends on loading impedance. In contrast, the SECE has a medium power gain, but the power gain is independent of the loading impedance. This thesis proposes a synchronous inversion and charge extraction (SICE) interface circuit for piezoelectric energy harvesting, combined with the SSHI and the SECE circuits, under the given number of inversions, the peak voltage of piezoelectric voltage is reversed (bias flip action), and then the total energy is extracted through the SECE circuit. Therefore, the advantages of high power gain and load independence can be obtained at the same time. According to the measurement results, when the peak of the piezoelectric voltage is 10 V and the number of inversions is 0, the extraction power is 130μW, and the power gain is 628%; When the peak of the piezoelectric voltage is 2.8 V and the number of inversions is 3, the extraction power is 22μW and the power gain is 628%.