Article
August 23, 2019

USB 3.0 Type-A to Type-A Cable Wiring Options


Many users may assume there is only one type of wiring for USB 3.0 Type-A Male to Type-A Male Cable. Actually, there are three different wiring configurations for USB 3.0 A to A cable assemblies for different applications.

1. Standard USB 3.0 A to A Wiring

USB 3.0 specification lists only one wire connection for USB 3.0 Standard-A Male to USB 3.0 Standard-A Male cable assembly. This cable intended to use for host-to-host connection, such as for operating system debugging.

For such applications, the wiring (Table 1) will be:

  • The 5V VBUS pin should not be connected to prevent current backflow to either USB host port.
  • The Pin to Pin connection for the SuperSpeed signal data pairs is not straight through but crossed over, so that the TX pair is connected to the RX pair, while the RX pair is connected to the TX pair.
USB 3.0 Standard-A Plug#1 Wire USB 3.0 Standard-A Plug#2
Pin Number Signal Name Wire Number Signal Name Pin Number Signal Name
1 VBUS No connect 1 VBUS
2 D- 2 UTP_D- 2 D-
3 D+ 3 UTP_D+ 2 D+
4 GND 4 GND_PWRrt 4 GND
5 StdA_SSRX- 5 SDP1- 8 StdA_SSTX-
6 StdA_SSRX+ 6 SDP1+ 7 StdA_SSTX+
7 GND_DRAIN 7 & 10 SDP1_Drain & SDP2_Drain 7 GND_DRAIN
8 StdA_SSTX- 8 SDP2- 5 StdA_SSRX-
9 StdA_SSTX+ 9 SDP2+ 6 StdA_SSRX+
Shell Shield Braid Shield Shell Shield
Table 1, Standard USB 3.0 A to A Wiring

2. Custom USB 3.0 A to A Special Wiring #1 – With VBUS and Data Pair Crossed-Over

Despite the wiring configuration for host-to-host connection application (as listed is Table 1 above), users sometimes need USB 3.0 A to A cable to connect with some types of adapters for host-to-device connection applications.

For such applications, the wiring (Table 2) will be:

  • The 5V VBUS need to be connected to provide USB bus power.
  • The Pin to Pin connection is crossed over for the SuperSpeed Data Pair.
USB 3.0 Standard-A Plug#1 Wire USB 3.0 Standard-A Plug#2
Pin Number Signal Name Wire Number Signal Name Pin Number Signal Name
1 VBUS 1 PWR 1 VBUS
2 D- 2 UTP_D- 2 D-
3 D+ 3 UTP_D+ 3 D+
4 GND 4 GND_PWRrt 4 GND
5 StdA_SSRX- 5 SDP1- 8 StdA_SSTX-
6 StdA_SSRX+ 6 SDP1+ 9 StdA_SSRX+
7 GND_DRAIN 7 & 10 SDP1_Drain & SDP2_Drain 7 GND_DRAIN
8 StdA_SSTX- 8 SDP2- 5 StdA_SSRX-
9 StdA_SSTX+ 9 SDP2+ 6 StdA_SSRX+
Shell Shield Braid Shield Shell Shield
Table 2, Custom USB 3.0 A to A Special Wiring #1

3. Custom USB 3.0 A to A Special Wiring #2 – With VBUS and Data Pair Straight Through

For some other special applications, in which all wire connections for USB 3.0 A to A cable need to be connected straight through with certain types of straight-through adapters (e.g USB 3.0 female to female coupler for wall plate) for host-to-device connections.

For such applications, the wiring (Table 3) will be:

  • The 5V VBUS need to be connected to provide USB bus power.
  • The Pin to Pin connection is straight through for the SuperSpeed Data Pair.
USB 3.0 Standard-A Plug#1 Wire USB 3.0 Standard-A Plug#2
Pin Number Signal Name Wire Number Signal Name Pin Number Signal Name
1 VBUS 1 PWR 1 VBUS
2 D- 2 UTP_D- 2 D-
3 D+ 3 UTP_D+ 3 D+
4 GND 4 GND_PWRrt 4 GND
5 StdA_SSRX- 5 SDP1- 5 StdA_SSTX-
6 StdA_SSRX+ 6 SDP1+ 6 StdA_SSRX+
7 GND_DRAIN 7 & 10 SDP1_Drain & SDP2_Drain 7 GND_DRAIN
8 StdA_SSTX- 8 SDP2- 8 StdA_SSTX-
9 StdA_SSTX+ 9 SDP2+ 6 StdA_SSTX+
Shell Shield Braid Shield Shell Shield
Table 3, Custom USB 3.0 A to A Special Wiring #2

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