USB C – the Future of Connectivity
What is USB-C?
USB-C, also referred to as USB Type-C, stands as the latest USB connector type developed by the USB Implementers Forum (USB-IF). The designation "C" sets it apart from its predecessors, namely the USB-A and USB-B connector group, which include standard B, mini, and micro B connectors. Unlike earlier USB cables, which were unidirectional (with USB-A connectors linking to hosts and USB-B connectors to devices), USB-C is designed to replace both. A standard USB-C to USB-C cable is bidirectional, facilitating connection in either orientation.
The primary objective of USB-C is to offer universal support for all existing and future USB data transfers. Presently, USB-C connectors accommodate data transfer ranging from early USB 1.1 to the latest USB4 v2 standards. However, this uniformity sometimes leads to confusion among users regarding the features of their USB-C cables. This guide aims to provide clarity on this matter.
USB-C Connector Types
Characterized by its oval shape, USB-C connector is engineered in a compact form factor, making it easily adaptable for smaller electronic devices like smartphones, tablets, and laptops. One of its standout features is its support for reversible plug-in orientation, finally resolving one of the most significant complaints in USB connector history.
USB-C connectors come in two primary types, distinguished by the number of pins it comes with: the Full Feature USB-C plug that comes with 22 pins and USB-C for USB 2.0 which comes with 12 pins.
USB-C Plug for USB 2.0
This plug contains a single differential channel (D+/D-) to support USB 2.0 at a maximum speed of 480Mb/s. It's commonly used for charging cables or for lower data rate peripherals such as microphones, keyboards, mice, and microcontroller units
Full Feature USB-C Pinout
Considered the complete form of USB-C, this plug features 22 pins, including the USB 2.0 data channel (D+/D-), four additional differential channels for SuperSpeed USB data (SDP), and one sideband channel (SBU). These additional channels enable support for higher USB data rates such as USB 3.2 and USB4, along with advanced features like DP alt-mode, PCIe tunneling, and more.
USB-C Speed for Data Transfer
Within the USB-C connector, two SuperSpeed differential pairs—one for transmitting data (TX) and one for receiving data (RX)—combine to form a USB SuperSpeed data lane. With four SuperSpeed differential pairs inside the USB-C connector, it can support a maximum of two SuperSpeed data lanes. Both the USB 3.2 and USB4 standards utilize either one or two lanes for USB data transfer, with speed varying according to each specification. The D+/D- channel remains dedicated to supporting USB 2.0 data, ensuring backward compatibility with USB 2.0/1.1 peripherals across all USB versions.
| USB Specification | Lane Rate | Number of Lanes | USB-IF Marketing Name | Logo |
|---|---|---|---|---|
| USB 3.2 Gen 1×1 | 5 Gbps | 1 | USB 5 Gbps |  |
| USB 3.2 Gen 2×1 | 10 Gbps | 1 | USB 10 Gbps |  |
| USB4 Gen 2×2 | 10 Gbps | 2 | USB 20 Gbps |  |
| USB4 Gen 3×2 | 20 Gbps | 2 | USB 40 Gbps |  |
| USB4 Gen4 | 40 Gbps | 2 | USB 80 Gbps |  |
USB-C Cable Length Limits
While both USB 3.2 and USB4 signals are transferred through the same SuperSpeed differential data lanes, the electrical characteristics differ according to the specification. As the data rate increases, signal integrity requirements become tighter, resulting in variations in the maximum USB-C cable length according to the standards. Active repeater cables are utilized to reach longer distances.
| USB Specification | Max. Data Transfer Rate | Passive Cable Max. Length | Newnex Active Cable Max. Length |
|---|---|---|---|
| USB 2.0 | 480 Mb/s | 10m | - |
| USB 3.2 Gen 2×1 | 5 Gb/s | 5m | 30m |
| USB 3.2 Gen 2x1 | 10 Gbps | 2m | 15m |
| USB4 Gen 2x2 | 20 Gbps | 2m | 4m |
| USB4 Gen 3x2 | 40 Gbps | 1m | 4m |
USB-IF Certification
When people think of USB, they often associate it with "Plug and play." To ensure such user-friendly experiences, the USB Implementers Forum (USB-IF) has established a compliance program. This program certifies USB cables and devices, affirming their adherence to the claimed USB standard. Especially with USB 3.2 and USB4 boasting data transfer speeds up to 10 to 80 times faster than previous USB 2.0 standards, compliance has become more critical than ever, setting a new standard for the craftsmanship and quality assurance of USB cable manufacturing.
Newnex Reaction
As one of the active developers and contributors to the USB standard, Newnex is dedicated to designing and manufacturing products that meet the requirements of all generations of USB specifications. We provide top-rated products to the professional USB user community. Learn more about Newnex USB-IF Certifications
USB-C Locking Connectors
In response to the growing need for secure interconnections among professional users, USB-IF has standardized USB-C locking connectors. This includes two types of industrial-standard locking mechanisms: single-screw and dual-screw locking USB-C connectors. Learn more about USB-C for Machine Vision
DisplayPort Alt-Mode
DP Alt-Mode, or DisplayPort Alt-Mode, was initially introduced by the Video Electronics Standards Association (VESA) in 2014. It enables the transmission of DisplayPort protocol signals over a USB-C connector. The DisplayPort signal utilizes the four SuperSpeed differential pairs within the USB-C interface to transmit DisplayPort data packets up to HBR3 mode, featuring 8.1 Gbps per DisplayPort Lane. Read more about DP Alt-Mode over USB-C
USB Power Delivery (PD)
USB Power Delivery is a groundbreaking technology that harnesses the USB-C interface to deliver significantly higher levels of power than conventional USB bus power. Enabled by the USB-C interface, the USB PD standard facilitates safe transfer of power between USB-C ports, accommodating various voltage and current profiles, with a maximum power delivery of up to 240W at 48V/5A. Read more about USB PD over USB-C
Thunderbolt Compatibility
Thunderbolt 3 and Thunderbolt 4 both utilize the USB-C physical connector for their cables, making Thunderbolt and USB-C cables appear nearly identical from the outside. Consequently, users may sometimes find it challenging to differentiate between a Thunderbolt and USB-C cable.
Most laptops equipped with Thunderbolt 3 and 4 ports are compatible with USB Type-C cables, allowing for USB data transmission speeds of up to 40Gbps. However, it's essential to note that USB cables can only be used with USB peripherals. Therefore, if you intend to connect a Thunderbolt device, you'll require a Thunderbolt cable. Hence, identifying the data protocol of your device becomes crucial.
Read more about Thunderbolt vs USB-COutlook and Summary
As USB4 v2 looms on the horizon, promising an impressive 80Gbps data rate, the potential of the USB-C connector is set to reach new heights. At the forefront of this remarkable connectivity technology, we are thrilled to witness its evolution and contribute to its advancements within the industry.
Looking forward, Newnex eagerly awaits opportunities to collaborate with USB-C adopters worldwide. With a steadfast focus on reliability and innovation, we remain committed to providing cutting-edge connectivity solutions. Together, we aim to shape a future where the USB-C interface continues to empower businesses and individuals with seamless connectivity experiences.