USB-Power Delivery (USB PD) is a fast charging specification formulated by the USB-IF organization and is one of the mainstream fast charging protocols. USB PD increases power delivery through USB cables and connectors, extending cable bus power capabilities in USB applications. This specification enables higher voltages and currents, delivers up to 100 watts of power, and can freely change the direction of power delivery. The USB-PD fast charging protocol is output through the Type-C interface, but it cannot be said that the USB-PD protocol fast charging must be supported with the Type-C interface.

The fast charging of mobile phones is mainly divided into three categories: VOOC fast charging technology, Qualcomm Quick Charge 2.0 fast charging technology, and MediaTek Pump Express Plus fast charging technology.