運動促進冗余電源控制器的設計

　　數據中心服務器、電信系統(tǒng)和軍事基礎設施等關鍵任務應用程序不能容忍任何故障或停機時間。因此，它們在冗余電源配置中使用兩個或多個電源，以確保如果一個電源故障，另一個電源可以無例外地提供全功率。ORing控制器IC是用來實現冗余電源配置。基本上，在這個方案中，兩個電壓輸入或輸出到一個共同的。在事件一輸入電源發(fā)生故障或短褲，ORing電路保護冗余總線與系統(tǒng)。冗余電源結構用于各種不同的總線電壓，范圍從5 V到48 V。

　　由于系統(tǒng)的功率水平和密度的需求，在過去是不嚴格的，ORing二極管主要用于這些應用程序。然而，隨著功率水平的上升和提供高效率解決方案的壓力不斷增加，傳統(tǒng)的方法已經不再適用于當今的高端系統(tǒng)，因為二極管具有很高的正向壓降。這意味著在高功率水平的高電流，功耗也很高。例如，一個典型的正向電壓下降為400毫伏的肖特基二極管，功耗為800毫瓦，或略小于1瓦，與2的電流單位。能夠處理這種功耗的二極管既大又昂貴。

　　While a MOSFET offers an attractive alternative solution because its on-state resistance RDS（on） is very low （typically a few milliohms）， and substantially lowers power loss as compared to a Schottky， it has a significant drawback. When a MOSFET is turned-on， current can flow in both directions through its channel. Consequently， if any input power source fails due to a short circuit， a large reverse current which can flow through the MOSFET and damage the redundant power source will be induced. Because of this， it is essential that the active ORing solution be very accurate and capable of extremely fast detection of reverse current fault conditions. To address this issue， the MOSFET is combined with a controller IC that can quickly detect the reverse current and shut the MOSFET off.