電源管理IC簡化集成超級電容器的能量microharvesting設計

　　能源microharvesting應用如無線傳感器節(jié)點需要周期性的爆發(fā)力量遠遠超出大多數環(huán)境來源的穩(wěn)態(tài)可用。在這方面，超級電容器提供了非常適合于能量收集環(huán)境的性能特性。由超級電容器適當的功率和充電管理電路相結合，利用從制造商包括線性技術，集成的專業(yè)設備，和德克薩斯的工具，工程師可以利用microharvesting技術應用要求的峰值功率要求。

　　電化學雙層電容器（電容器），或超級電容器，能夠排出幾十甚至幾百毫安的電流在幾秒鐘的過程（見高新區(qū)的文章“超級電容器滿足能量收集應用的獨特需求）。例如，對于無線傳感器節(jié)點應用而言，這種功率輸出在無線通信突發(fā)的峰值需求包中很好。超級電容器的高效充放電循環(huán)使其非常適合于突發(fā)式應用，如無線傳感器節(jié)點。

　　Similarly， their efficient charge/discharge characteristics make them well suited to specialized demands of microharvesting applications that must periodically “cold boot” after an extended absence of ambient energy has depleted all onboard charge storage devices. Here， the full application circuitry is reenergized sequentially after microharvesting circuitry first charges a bootstrap supercapacitor used to power subsequent stages of the bootstrap process.

　　A typical microharvesting application uses supercapacitors as the sole storage device or as supplemental storage for peak or cold boot requirements （Figure 1）。 For load management， a DC/DC converter is required to maintain a stable supply voltage to the load because the voltage output of a supercapacitor is linearly proportional to the charge on the supercap. Engineers will typically use a buck-boost converter with low dropout to extract maximum power from the supercap even as charge levels drop under load.