The technical points of USB chargers mainly include the following aspects:
USB PD technology: USB Power Delivery (USB-PD) is a power transmission protocol based on the USB Type-C interface, which aims to achieve higher power transmission through a single USB connection. USB-PD supports multiple voltage and current configurations, up to 100W or even 240W charging power. Its working principle is to communicate between the power adapter and the device through the configuration channel (CC pin), negotiate the required voltage and current, and ensure safe and efficient charging of the device.
Voltage and current configuration: USB-PD supports multiple voltage and current configurations, including 5V, 9V, 12V, 15V and 20V voltages, and a maximum current of 5A. In practical applications, the voltage on VBUS is first increased while the maximum current is maintained at 3A. After reaching the maximum voltage of 20V, the current can be adjusted to 5A (special cables and e-mark chips are required).
Intelligent negotiation and dynamic adjustment: USB-PD performs intelligent power negotiation through the CC pin to ensure safe and efficient charging of the device. During the charging process, the device and the power adapter can dynamically adjust the voltage and current to optimize charging efficiency and safety. This dynamic adjustment requires support for the PPS (Programmable Voltage Regulation) function.
Bidirectional power supply: USB-PD supports bidirectional power transmission, and the device can act as both a power provider and a power receiver. This means that two devices that support USB-PD can be connected via a USB cable to charge each other, improving the portability and application scenarios of the device.
Compatibility and safety: USB interfaces are widely used in various devices. Users only need one USB charging cable to charge multiple devices, reducing the trouble of carrying multiple chargers. In addition, the voltage and current of USB chargers follow strict standards to ensure safe use.
