USB 3.0 Header is a 20 pin 2mm pitch header using the less common ICC pin numbering. The header has a key slot on the pin 1-10 side if enclosed.
USB 2.0 Header is a 10 pin .1 pitch header using the standard IDC pin numbering. The header has a key slot on the pin 1-9 side if enclosed. (The 10-pin IDC male graphic shown has the keying on the wrong side).
Both headers contain two ports each, and have a missing pin for filled female connectors.
USB 3.0 | USB 2.0 | |||||
---|---|---|---|---|---|---|
Pin (ICC) |
Equivelent IDC Pin # |
Pin Name |
Description | Port | Pin Name |
Pin (IDC) |
1 | 1 | VBus | +5V Power | 1 | +5V | 1 |
2 | 3 | SSRX1- | SuperSpeed recevier | |||
3 | 5 | SSRX1+ | ||||
4 | 7 | GND | Ground for Power | GND | 7 | |
5 | 9 | SSTX1- | SuperSpeed transmitter | |||
6 | 11 | SSTX1+ | ||||
7 | 13 | DRAIN | Ground for Shield Drain | Shared pin 10 | ||
8 | 15 | D1- | USB 2.0 data | D1- | 3 | |
9 | 17 | D1+ | D1+ | 5 | ||
10 | 19 | NC | ||||
11 | 20 | D2+ | USB 2.0 data | 2 | D2+ | 6 |
12 | 18 | D2- | D2- | 4 | ||
13 | 16 | DRAIN | Ground for Shield Drain | S-GND | 10 | |
14 | 14 | SSTX2+ | SuperSpeed transmitter | |||
15 | 12 | SSTX2- | ||||
16 | 10 | GND | Ground for Power | GND | 8 | |
17 | 8 | SSRX2+ | SuperSpeed recevier | |||
18 | 6 | SSRX2- | ||||
19 | 4 | VBUS | +5V Power | +5V | 2 | |
20 | 2 | No Pin | Space of Filled Keying | No Pin | 9 |
The standard USB 2.0 Header is missing pin 9 (for keying), but logically pin 9 is for port1's Sheild GND. The sheild is left unconnected if a single port cable is plugged in to port 1. Dual Port hear connectors, share port 10 for both sheilds
This is the most common USB 2.0 header (10 pin [2x5], missing pin 9) and it is pin compatable with the rare 8 pin [2x4] version (missing pins 9 and 10) and 10 pin [2x5] (no pins missing). It is not pin compatable with the very rare (10 pin [2x5], missing pins 10 and 2).
A new feature of USB 3.0 is the SuperSpeed bus, which provides a fourth transfer mode at 5.0 Gbit/s, this is simply left out of the 2.0 header.