USB 3.0 Type-A Pinout
The 9-pin SuperSpeed Standard-A connector - USB 2.0 plus a SuperSpeed second row.
Overview
USB 3.0 Standard-A keeps the four legacy USB 2.0 contacts in the front row and adds five SuperSpeed contacts in a recessed back row, for 9 pins total. It is backward compatible: a USB 2.0 plug mates only with the front row.
SuperSpeed uses two extra differential pairs (SSTX, SSRX) plus a ground drain, enabling 5 Gbps.
Pinout
| Pin | Name | Function | Description |
|---|---|---|---|
| 1 | VBUS | POWER | +5 V bus power |
| 2 | D- | USB2 / DATA | USB 2.0 data, negative |
| 3 | D+ | USB2 / DATA | USB 2.0 data, positive |
| 4 | GND | POWER / GND / USB2 | Ground (USB 2.0 / power return) |
| 5 | StdA_SSRX- | USB3 | SuperSpeed receive, negative |
| 6 | StdA_SSRX+ | USB3 | SuperSpeed receive, positive |
| 7 | GND_DRAIN | GND / USB3 / SIGNAL | Ground for SuperSpeed signal return / shield drain |
| 8 | StdA_SSTX- | USB3 | SuperSpeed transmit, negative |
| 9 | StdA_SSTX+ | USB3 | SuperSpeed transmit, positive |
Notes
- Pins 1-4 are the legacy USB 2.0 row (backward compatible); 5-9 are the SuperSpeed row.
- Signal names use the StdA_ prefix in the USB-IF spec; RX/TX are from the host perspective.
Reference: USB 3.0 specification (USB-IF) / aggsoft USB3 pinout· verified 2026-06-27