用于能量收集應用的電源管理IC的選擇

　　電源管理IC（PMIC）支持和管理傳感器和能量采集通道、儲能元件（電池，傳統的電容器或超級電容器），和處理器/無線鏈路。這種能量收集設計的關鍵塊實現了幾個主要功能：

　　捕捉和提取隨機，從源傳感器微小的能量

　　將提取的能量轉換為存儲元件的能量，通常是通過DC / DC轉換器。

　　管理來自存儲元件的電源流出，同時確保當存儲的能量低于閾值且不會被浪費時，電源不會被抽出。

　　也許最具挑戰性的，它必須管理它自己的啟動順序從轉型的時候有足夠的可用存儲的能量為PMIC本身

　　用于能量收集系統的設計師，也有好消息：對PMIC的更多的選擇，現在可以從供應商，每個具有不同的屬性和特點。有些是為一個特定的收獲源優化，而其他人更一般；有些實現是PMIC作用的一部分，而其他人將更多的基本功能。

　　Engineers should always keep in mind that all energy-harvesting designs are based on one principle – to accumulate over time the trickle of minuscule， sporadic energy from the source， store it， and then release it as a power pulse when needed by the rest of the system for data collection， analysis and transmission. Therefore， there are long quiescent periods when the PMIC‘s only activity is to allow the energy to flow to the storage element and little else， as well as periods when there is no incoming energy.

　　You must also be aware that a conventional DC/DC switching converter core， no matter how efficient， is generally not a good choice for energy harvesting. This is because these are designed to work with a consistent source such as battery， which is a low-impedance， somewhat regulated source. Further， the DC/DC switching converter of a PMIC must have extremely low quiescent current requirements， as there may be long periods without available source energy and thus no power-converter activity.