SuperSpeed USB
Last modified by Microchip on 2023/11/10 11:19
SuperSpeed Universal Serial Bus (USB) was first introduced in 2008 with the release of the USB 3.0 specification. In 2015, USB 3.0 was renamed USB 3.1 Gen 1 to avoid confusion.
SuperSpeed USB Significant Features
- Speeds of up to 5 Gbit/s are supported
- Backwardly compatible with all speeds defined in USB 2.0
- New and slightly larger connectors are used for SuperSpeed USB than are used with USB 2.0. The hub receptacles receiving these connectors can also accept the standard 2.0 connectors.
- Implements 8 b/10 b encoding in a Full-Duplex Communications mode.
Data Signals
SuperSpeed USB uses six data lines configured in two groups:
- D+ and D- differential half-duplex signals
- Two pairs of full-duplex differential signals ( SSTX-, SSTX+, and SSRX-, SSRX+)
| Pin Number | Signal | Description |
|---|---|---|
| 1 | VBUS | Power |
| 2, 3 | D- , D+ | 2.0 Differential Pair |
| 4 | GND | Ground |
| 5, 6 | SSRX- , SSRX+ | SuperSpeed receiver differential pair |
| 7 | GND_DRAIN | Ground for return signal |
| 8, 9 | SSTX- , SSTX+ | SuperSpeed transmit differential pair |
SuperSpeed Power Distribution
USB 3.0 provides for low-power and high-power ports. Both of these ports are able to supply their specified current while maintaining 5 Gbit/s transfers.
- Low-power ports provide up to 150 ma
- High-power ports provide up to 900 ma
There are several power delivery specifications cable of supplying additional power. Not all modes can sustain the data transfer while supplying power (see the power delivery specifications for details).
Notes
- Many observers believe SuperSpeed USB will be quickly eclipsed by 10 GB SuperSpeed + USB
- The full SuperSpeed USB specifications are available from USB Document Library.