What is USB PD3.0 (Power Delivery 3.0)?

Aug 22, 2022

What is USB PD3.0 (Power Delivery 3.0)?

USB PD3.0 (Power Delivery 3.0) is a power supply standard based on the USB Type-C interface. The maximum power supply can reach 100W(watts). The connectors at both ends of the PD 3.0 compliant cable must be Type-C, which means that PD3.0 will not be applied to the common USB-A cable we used before, but only USB-C to USB-C Cable; With the popularity of the USB Type-C interface, more and more devices have begun to use the USB PD fast charging solution. For example: mobile phones, tablets, monitors, chargers, even lamps, electronic scales, small appliances, toys, etc.

For detailed protocol standards of USB PD 3.0, please refer to: USB Power Delivery

USB PD3.0 is only related to the power supply of the cable, and has nothing to do with the data transmission. Traditional USB-A charging cables can be only two wires, VBUS and Gound. However, a USB-C to USB-C cable that complies with PD 3.0 requires at least three wires, VBUS, Gound and CC (Channel Configuration). The CC wire can communicate and define the role of the power supply during the connection between the two devices.

Before the Type-C interface appeared, the USB cable was only allowed to provide 2.5W of power, while the USB Type-C cable allowed the maximum power to be up to 5V/3A (15W). If the Power Deliver (PD) protocol is adopted, the voltage and current can be increased to 20V/5A (100W), which allows the power supply of large devices through the USB interface, such as charging a laptop with a large battery.

The new USB PD 3.0 protocol also supports the Programmable Power Supply (PPS) protocol, allowing precise regulation of the voltage and current of the bus. Using this protocol, a high-efficiency direct-charging system that directly charges the battery with an adjustable bus voltage becomes possible, and the bus voltage can be as low as 3V.