What kind of connector do I need for a USB Type-C charging cable?

At a high level, the latest USB Type-C standard only defines the physical connector users see in many of today's phones and electronic devices. Data transfer protocols like USB 3.2, and even the latest USB 4, only apply to electrical signals. While often used together, engineers can create a system using the USB 3.2 data transfer specification with its own proprietary connector that doesn't conform to the physical USB connector standard.

The same is true for the USB Power Delivery (PD) specification. Due to its design, the USB Type-C connector supports a maximum rated current of 5A and a rated voltage of 20V _DC , enabling power delivery capabilities up to 100W as defined in USB PD 3.0. While the USB Type-C connector can support USB PD, the power delivery specification is actually controlled by the charging circuitry and is limited only by the voltage and current capabilities of the physical connector. However, the higher power delivery capabilities supported by USB Type-C connectors have opened them up to a new world of power delivery applications.

The standard 24-contact USB Type-C connector has 16 data transmission contacts, 4 power contacts, and 4 ground contacts, supporting power delivery of up to 100 W. This makes the USB Type-C connector an attractive solution for power applications, capable of replacing standard DC power connectors even when data transmission is not required.

Standardization is one of the primary advantages of using USB for power delivery. USB connectors are widely adopted across many different industries, and Type-C continues to establish itself as the universal connector for phones and mobile devices. For this reason, the European Union has discussed the possibility of adopting the USB Type-C connector as the standard for all future devices purchased and sold within its jurisdiction. For end users, the convenience of being able to connect a wide range of products with a single, readily available cable is self-evident. OEMs also benefit from a stable supply chain, as USB connectors are readily available and their standardization ensures a certain level of interoperability. This standardization also reduces design integration challenges. Furthermore, USB Type-C connectors typically offer a smaller footprint than many barrel connectors and offer high reliability and long life, rated for up to 10,000 mating cycles.

Given the advantages listed in the previous section, CUI Devices has developed a power-only USB Type-C receptacle for applications where the intended use is solely for charging or power delivery. CUI Devices' power-only USB Type-C receptacle eliminates the 16 data transfer contacts and two ground contacts, leaving only four power contacts and two ground contacts.

Figure 2: Comparison of 24-contact Type-C and 6-contact power-only Type-C (Image source: CUI Devices)

Compared to the standard 24-contact Type-C connector, this connector eliminates 16 contacts, leaving only 6. This simplified design significantly reduces costs. This not only lowers part cost but also reduces complexity and failure rates due to fewer failed contacts and associated solder joints. While these power-only USB Type-C connectors do not transmit data, they remain compatible with all standard data + power USB Type-C cables. This increases their convenience, as no additional hardware or requirements are required when connecting the connector to the cable.

While the USB Type-C connector is suitable for a wide variety of applications and designs, specialized power delivery products, such as DC power connectors , still have their place. Most importantly, the USB Type-C connector is limited to 100W power delivery, making it an impractical option for designs requiring more than 100W. While a standardized footprint is beneficial in many cases, there are also instances where a different footprint or package type may be a more suitable option.

In other words, when a more customized connector is needed, USB Type-C may be limited by its standardized size and limitations. For more information on situations where other power connectors may still be the best solution, read CUI Devices' blog on Selecting a DC Power Connector .

The USB Type-C connector and its widespread adoption offer engineers a new way to look at power management and delivery. While not a one-size-fits-all solution, Type-C's ability to deliver up to 100W of power and global standardization give it a strong foothold in a wide range of products and applications. With its low cost and simplified design integration, CUI Devices' power-only USB Type-C receptacles offer engineers an attractive option when power delivery is the only function.

CUI Devices currently offers a 60W power-only USB Type-C receptacle with a maximum current rating of 3A and a maximum voltage rating of 20V _{DC . A 100W version is in development and will be available soon. This version will have the full 5A current rating and 20V DC} voltage rating supported by the USB Type-C connector .