USB Cables and Connectors
Last modified by Microchip on 2025/05/23 05:43
Cables
Traditional Cables
| Specification | Speed | Number of Lines | Maximum Length |
|---|---|---|---|
| 1.0 | Low | 4 (VBUS, Gnd, D+, D-) | 5 |
| 1.0 | Full | 4 (VBUS, Gnd, D+, D-) | 5 |
| 2.0 | High | 4 (VBUS, Gnd, D+, D-) | 5 |
| 3.0 | Superspeed | 9 (VBUS, Gnd, D+, D- SSRX-, SSRX+, Gnd, SSTX+, SSTX-) | 3 |
| 3.1 | Superspeed + | 9 (VBUS, Gnd, D+, D- SSRX-, SSRX+, Gnd, SSTX+, SSTX-) | 3 |
USB Type-C® Cables
USB Type-C® calls for a cable with 24 signals:
Depending upon the mode of operation, all of the signals may not be needed.
- When running in USB 2.0, only the signals associated with 2.0 (VBUS, GND, D+, and D-) and VCONN need to exist.
- To be USB 3.x compliant all the lines must be present.
- To allow Type-C Alternate mode to run, the following pins need to be able to be re-allocated: TX1+/-, TX2+/-, RX1+/-, RX2+/-, SBU1, and SBU2. If these signals are not used in the Alternate mode, they may be eliminated.
Electronically Marked Type-C cables
USB Type-C provides for a cable containing embedded circuitry. The circuitry may draw up to 70 mA which can be drawn from either VBUS or VCONN. An electronically marked Type-C cable is required when running under Specification 3.1 or when executing the Power Delivery 2.0 protocol.
Connectors
Traditional Plugs and Connectors
Type-A connectors face the host. Type-B connectors face the device.
| Connector Type | Pinout | Picture | Notes |
|---|---|---|---|
| Type A |  |  | Operates in USB 2.0 mode, if plugged into a USB 3.0 A receptacle. |
| Type B |  |  | Operates in USB 2.0 mode, if plugged into a USB 3.0 B receptacle. |
| Mini B |  |  | |
| Micro A |  |  | |
| Micro B |  |  | Operates in USB 2.0 mode, if plugged into a USB 3.0 Micro B receptacle. |
| 3.0 Type A |  |  | Operates in USB 2.0 mode, if plugged into a USB 2.0 A receptacle. |
| 3.0 Type B |  |  | |
| 3.0 Micro B |  |  |
Type-C Connector
The USB Type-C connector has a 24-pin count and is reversible.
