Charging Protocols for USB A Ports:

1.USB BC 1.2 (Battery Charging 1.2)
This is the most basic charging protocol for USB A ports. It supports a maximum output of 5V/1.5A, roughly 7.5W.

2.QC (Quick Charge)
Developed by Qualcomm, this fast-charging protocol supports various voltage and current levels, such as 5V/2A or 9V/2A. QC 3.0 can dynamically adjust the voltage to improve charging efficiency, with a maximum output of 18W (e.g., 9V/2A).

3.AFC (Adaptive Fast Charging)
Developed by Samsung, this protocol is similar to QC and also supports different voltage levels, such as 9V/1.67A, with a maximum output of 15W.

4.FCP (Fast Charge Protocol)
Developed by Huawei, this protocol supports 9V/2A, with a maximum output power of 18W.

5.SCP (SuperCharge Protocol)
Also developed by Huawei, this protocol supports higher currents, such as 5V/4.5A, with a maximum power output of 22.5W.

6.Apple 2.4A
Used by Apple devices, this protocol supports 5V/2.4A, with a maximum output of 12W.

7.DCP (Dedicated Charging Port)
A dedicated charging port protocol that allows USB A ports to provide higher power, typically up to 5V/2.4A.


USB A ports primarily enhance charging speed by adjusting voltage and current. Unlike USB-C ports with Power Delivery (PD) protocols, which offer higher power and bi-directional power delivery, USB A focuses on simpler power management to improve charging efficiency.

USB A 口通常通过以下几种协议进行充电：

1.USB BC 1.2 (Battery Charging 1.2)
- 这是USB A口最基础的充电协议。最大输出为5V/1.5A，约7.5W。

2.QC (Quick Charge)
- 由高通推出的快充协议，支持不同电压和电流档位，如5V/2A、9V/2A等。QC 3.0甚至可以动态调节电压，提高充电效率，最高支持到18W（如9V/2A）。

3.AFC (Adaptive Fast Charging)
- 三星开发的快充协议，和QC协议类似，也支持不同电压档位，如9V/1.67A，最大输出15W。

4.FCP (Fast Charge Protocol)
- 由华为推出的快充协议，支持9V/2A，最高18W的输出功率。

5.SCP (SuperCharge Protocol)
- 也是华为的快充协议，支持更高的电流，如5V/4.5A，最大功率22.5W。

6.Apple 2.4A
- 苹果设备使用的协议，支持5V/2.4A，最大12W的充电功率。

7.DCP (Dedicated Charging Port)
- 专用充电口协议，允许USB A口进行更高功率的充电，通常可达到5V/2.4A。
总结：USB A口的充电协议主要是通过调整电压和电流来加快充电速度，而不像USB-C口的PD协议那样复杂，可以实现高功率双向供电。

Charging Protocols for USB C Ports:

1. USB Power Delivery (PD)
- PD is the most important protocol for USB-C, supporting programmable power output with voltage ranges from 5V to 20V and up to 240W of power (USB PD 3.1). PD also supports bi-directional power, meaning the device can charge or supply power to other devices via the same USB-C port.

2. Qualcomm Quick Charge (QC)
- Originally designed for USB A, newer versions of QC (like QC 4.0 and QC 5.0) are compatible with USB-C and even integrate with PD, allowing for up to 100W of power depending on the device and charger.

3.PPS (Programmable Power Supply)
- PPS is an extension of the PD protocol, allowing devices to adjust the voltage in small increments (e.g., 20mV), improving charging efficiency and reducing heat generation, especially during high-power charging. PPS can support up to 45W or more for devices that utilize super-fast charging.

4. Apple Fast Charge
- While not officially named, Apple devices like iPhones and iPads support fast charging via USB-C, using the PD protocol with power levels ranging from 18W to 30W.

5. SuperCharge (SCP)
- Developed by Huawei, SCP uses USB-C and can support up to 66W of power. The latest versions of SCP allow stable charging at higher voltages with consistent current flow.

6. VOOC / SuperVOOC
- OPPO’s proprietary fast charging protocols use USB-C, leveraging high current and low voltage for fast charging. The latest **SuperVOOC** version supports up to 65W or even higher power.

7. Dash Charge / Warp Charge
- OnePlus’s fast charging protocols use USB-C, with Dash Charge offering 20W (5V/4A) and Warp Charge supporting up to 65W.

8. Adaptive Fast Charging (AFC)
- Developed by Samsung, AFC uses USB-C to support fast charging with varying voltage and current levels, similar to QC, reaching up to 25W or 45W.

Conclusion
The USB-C interface’s core charging protocol is **PD**, but it also supports other fast-charging protocols like **QC**, **PPS**, and **VOOC**. Compared to USB A, USB-C offers a broader power range, bi-directional power delivery, and smarter voltage regulation, significantly enhancing charging speed and efficiency.

USB C 口通常通过以下几种协议进行充电：

1. USB Power Delivery (PD)
- PD协议**是USB-C最重要的充电协议之一，支持可编程电源输出，能提供5V到20V的电压范围，并且最大功率可以达到240W（USB PD 3.1）。PD协议还支持双向供电，这意味着设备不仅可以通过USB-C口充电，还可以通过同一接口为其他设备供电。

2. Qualcomm Quick Charge (QC)
- 尽管QC协议最初是为USB A设计的，但最新的QC版本（如QC 4.0和QC 5.0）也支持USB-C接口，甚至与PD协议兼容，最高支持100W的功率（取决于设备和充电器）。

3. PPS (Programmable Power Supply)
- PPS协议**是一种PD的扩展协议，允许设备在充电过程中以小的步进（如20mV）调节电压，从而提高充电效率，减少发热，尤其是在高功率充电时。PPS协议通常用于支持超级快充的设备，功率最高可达45W或更多。

4. Apple Fast Charge
- 虽然没有特别的名称，但苹果的设备（如iPhone和iPad）通过USB-C接口支持快速充电，采用PD协议，支持18W到30W的快充。

5. SuperCharge (SCP)
- 华为开发的快充协议，部分通过USB-C实现，支持最高66W的充电功率。最新的SCP协议可以在更高的电压下以稳定的电流进行充电。

6. VOOC / SuperVOOC
- OPPO开发的快速充电协议，VOOC协议采用USB-C接口，并且通过高电流低电压实现快速充电。最新的SuperVOOC协议可支持到65W甚至更高功率。

7. Dash Charge / Warp Charge
- 这是OnePlus推出的快充协议，通常采用USB-C接口。Dash Charge支持5V/4A的20W充电，而Warp Charge最高可达到65W。

8. Adaptive Fast Charging (AFC)
- 由三星开发，支持通过USB-C接口以不同的电压和电流进行快速充电，类似于QC协议，最高可达25W或45W。

总结
USB-C接口最核心的充电协议是PD协议，但它还兼容其他快充协议，如QC、PPS、VOOC等。相比传统的USB A接口，USB-C不仅在功率范围上更广，而且支持更多高级功能，如双向供电和智能电压调节，进一步提升了充电的速度和效率。