Today, we mainly introduce the following USB Power Delivery fast charging protocols by USB-IF organization:
USB PD and USB Type-C™ is a new connector technology that provides great expansion capabilities. It provides 22 pins, while Type-A/Type-B connectors only provide 4 pins. It can instead of the power socket (100W), provide additional pins for USB PD and higher rated current 3A-5A, while Type-B's rated current is only 2A.The USB Type-C™ technology is universal and versatile. Both ends of the cable are USB Type-C™ connectors, and there is no difference in the insertion of the connector. It is suitable for all mobile, computing and TV applications, and is supported by all major consumer OEM manufacturers. Moreover, it is much smaller than Type-A and can achieve a smaller size design.
USB PD 2.0 standard function USB PD is a communication protocol that runs through the configuration channel pins (CC1/CC2) on the USB Type-C™ connector. USD PD 2.0 provides standard functions via USB PD Powered Data Objects (PDO). The standard PDO structure allows up to 7 discrete voltage levels (related to current limit per step). There are multiple product options that can cover PDOs with different system functions.
USB PD expansion function USB PD 3.0 is backward compatible with USB PD 2.0, and adds direct charging. The theoretical maximum rate is 5.0Gbps (ie 500MB/S). It provides a new type of enhanced power supply data object (APDO) for programmable power supply (PPS) mode. Mobile devices can request and control the output voltage of the power adapter within a specified range with high precision, and achieve programmable current foldback. It provides a new mechanism to support direct charging and other charging algorithms. PPS requires 20mV/step voltag resolution, and the minimum voltage can be reduced to 3.3V. Portable power adapters designed with PPS can directly charge batteries in mobile devices, including smartphones. This helps solve the heat dissipation and cost challenges of power management on mobile devices.
In addition, the USB-IF organization released an important update of USB PD 3.0 in 2017, officially launched the PPS (Programmable Power Supply) aimed at unifying the fast charging technical specifications, and successfully included QC4.0 of Qualcomm, which is PD fast charging at this time. It can be compatible with the QC4.0 fast charge agreement in Qualcomm. This is of particular importance for the unified fast charging technical specifications.
