設計USB Type-C和使用電源快速充電

　　USB已經(jīng)從一個數(shù)據(jù)接口，能夠提供有限的電源到一個主電源與一個高速數(shù)據(jù)接口。USB Type-C?和USB供電（PD）2（和即將到來的3版）加速了這一演變。然而，需要謹慎選擇應用USB Type-C USB PD提供多個功率水平的最具成本效益的解決方案。

　　例如，USB Type-C就可以支持高達5伏3安培（15 W），而USB PD USB Type-C使生態(tài)系統(tǒng)支持多種功率最高可達20伏，5安培（100 W）。缺點是，USB PD增加設計的復雜性和成本的材料清單（BOM）。

　　Fortunately， by using a range of recently introduced components， designers can take advantage of new capabilities such as reversible power delivery， power negotiation and the 100 watt power delivery to design USB power supplies that charge devices – even portable computers – safely and quickly.

　　This article attempts to cut through the complexity of USB Type-C and USB PD by explaining how designers can use USB Type-C for many applications and when they should migrate to USB PD for higher power applications. The article will then provide guidance on how to implement practical USB Type-C and USB PD designs.