USB Type-C is a major improvement of the USB port. It has faster speed and stronger power transmission performance. It can transmit data and video at a high speed and improve the power transmission capacity. These unique advantages of Type-C allow consumers to complete charging, video or data transmission only with Type-C cables, without the need for multiple cables. Manufacturers only need to design and equip Type-C ports on their devices to support different purposes.
Type-C has multiple functions because USB cables, ports, adapters, and hubs all use more complex embedded components instead of simple internal working components in the past. The seemingly simple HDMI to Type-C Cable is actually difficult to design, because the design requires the use of embedded components. There are two main problems to be dealt with when designing a Type-C solution. One is to deal with the problem of power supply range, and the other is to deal with the problem of communication failure due to the adoption of higher communication standards. When connecting two devices, the power transmission protocol needs to be activated. This process will negotiate the power to be transmitted and who is the power supplier and power user. Because this communication process needs to detect, read and process analog and digital signals, it is necessary to embed MCU modules in the host port, cable or adapter to realize the MCU function. If the devices or the host and the device do not support each other, communication cannot be established, and a malfunction may occur. Detect the device, and then the device communicates with the host, which also requires MCU functionality.
USB Type-C not only reduces the number of cables, but also ensures smooth transmission between devices, simplifying the complexity of operations for users and consumers. However, this will cause problems for designers and developers.
Type-C cables and adapters
Users who wish to use older peripherals need to use conversion cables or adapters. There are many such situations. The first is to simply convert USB 2.0 to Type-C. Since USB 2.0 does not support higher speeds and the voltage or current of Vbus does not exceed 5V or 3A, the cable can be simply switched from D+/D-, Vbus and GND Connect to the connector. The second is a Type-C to Type-C cable, an adapter that converts USB 3.0/1 to Type-C, or an adapter whose Vbus voltage or current exceeds 5V or 3A. Design this cable or The connector is more difficult.
In these cases, the adapter becomes a part of the power negotiation between the two devices, so the cable or adapter is required to use an embedded PD controller. The PD controller is initially powered by the Vbus or Vconn channel set to 5V. Subsequently, it negotiates with the host to set a consistent power level on the Vbus channel.