具支援USB-PD系統之前瞻電源模組

Abstract

現代化生活中對於3C電子產品的充斥及依賴與日俱增，每日都會使用到的充電器、筆記型電腦、平板電腦電源供應器等琳瑯滿目，不同的接頭形式、不同的供電電壓、負載電流，在汰舊換新的過程中必須一併更新，既浪費資源亦對環境造成衝擊。因此歐盟訂定新手機充電孔一律採用Micro USB介面才可上市的法令，但對於筆記型電腦或平板電腦的充電要求上，並無統一的規範。為符合節能減碳的要求並提供不同裝置上的供電應用，國際USB開發者論壇(USB Implementers Forum,簡稱USB-IF)於2012年7月正式制訂USB Power Delivery(簡稱USB-PD)技術規格，可同時相容於USB 2.0與3.0兩種主流規格，透過USB介面傳遞電力，可同時進行資料傳輸的任務。而雙向且靈活的運用，使得USB-PD規格成為眾所期待的新技術應用。 本論文提出具支援USB-PD系統之前瞻電源模組，具備低成本、高效率及低功耗並能符合USB-PD的要求，依不同的電源需求改變輸出電壓及負載能力。此模組以Flyback為架構基礎，切換在不連續導通的模式下，利用波谷切換技術確保系統有最小的切換損失及同步整流技術確保系統有最小的導通損失，以達到高效率的要求。並利用節能機制在極輕載的條件下有最低的功率消耗。相較於傳統的控制法，在輸出100瓦時效率可以達到88%以上，整體平均效率可達90%以上，而輕載待機功率低於10mW。

Modern life is full and rely increasingly for 3C electronic products, will be used daily to the charger, notebook computers, tablet PCs and other dazzling power supply, the different forms of joints, different supply voltage, load current, eliminating the old renewal process must be updated to a waste of resources also impact on the environment. Therefore, The EU has developed a new decree, phone charging holes must use the Micro USB interface can only be listed, but for the laptop or tablet PC charging requirements, there is no uniform standard. To comply with the requirements of energy saving and carbon reduction, USB Implementers Forum (referred to as USB-IF) formally formulate USB Power Delivery (referred to as USB-PD) technical specifications in July 2012 to provide powered applications on different devices, can compatible with USB 2.0 and 3.0 two mainstream specifications, through the USB port provides power and data transfer tasks at same time. This two-way flexibility makes USB-PD specification become a new technology awaited. This paper presents an advanced power module can support USB-PD system, with low cost, high efficiency and low power consumption, and can meet the requirements of USB-PD, depending on power requirements change the output voltage and load capacity. This module architecture is based on Flyback and operated in discontinuous conduction mode, in order to achieve high efficiency use of valley switching and synchronous rectification technologies to ensure the system have minimum switching and conduction losses. Also using Green mode mechanism under very light load conditions to achieve lowest power consumption. Compared to the conventional control method, when output power is 100 watts the efficiency can reach 88% and the average efficiency is higher than 90% while the light-load power consumption is less than 10 mW.