Universal Serial Bus

Super-Speed USB Interface

[USB Description]
[USB Interface ICs]
[USB Pinout] [USB Connector]
[USB Standard / Organizations]
[Converter, Adapter, Cables]

SuperSpeed USB Description

The USB [Universal Serial Bus] 3.0 specification defines the Mechanical, Electrical and Protocol layers of the interface. Cables and connectors are fully defined and retain backward compatibility with the USB 2.0 Type-A connectors. USB defines 2 types of hardware, Hubs and Functions. Revision 3.0 of the USB standard is called SuperSpeed USB. Up to 127 devices may be connected together in a Tiered Star Topology. The limiting factor being 7 address bits. The physical wire segments are point-to-point between a Host, Hub, or Function. The system may only have one Host, which connects to a Hub. A USB Hub may connect to another Hub or to a USB Function. Each layer transition from Hub to Hub represents another Tier. USB Hubs allow connection to a USB bus, while USB Functions are the devices which perform some function.

As of January 2010 products supporting USB3.0 were just starting to be released, with a few more by 2011.

The USB bus is a [Differential] Bi-directional serial interface cable bus. Differential NRZI data is transmitted Isochronous or Asynchronous between devices. Data is transferred at three different rates over a maximum cable length of 4 meters ~ over 4 wires, 2 of which carry data on a balanced twisted pair.
SuperSpeed USB [3.0] allows operation up to 4.8Gbps, and while operating in the compatibility mode USB [2.0] may operate at any speed from 10kbps to 480Mbps in one of three speed modes. A Slow-Speed mode of 10kbps to 100kbps is used for devices such as a USB keyboard or USB mouse. Full-Speed mode is used by most devices and allows a transfer rate of 500kbps to 10Mbps. High-Speed mode allows rates of up to 480Mbps, with a speed range of 25Mbps to 400Mbps. Transmission at the High-Speed mode requires the addition of 45 ohm termination resistors between each data line and ground. Operation at Full-Speed mode is 2.8 volts [High] to 0.3 volts [Low]. Operation at High-Speed mode is at 400mV +/-10% [High] to 0V +/- 10mV {Low]. Cable impedance for both modes is 90 ohms +/- 15% (differential).

Four different (packet) protocols are used; Control, Interrupt, Isochronous and Bulk. Each exchange contains 3 packets; A token packet which holds the address, a data packet which holds the data, and a handshake packet which terminate the exchange.
NRZI produces a change in the signal indicating a logic zero, no change indicates a logic one. Bit stuffing is used with NRZI to stop the signal remaining in the steady state condition; if more then 6 ones are transmitted (no change in the signal) a zero is inserted to produce a transition. NRZI, with bit stuffing is self clocking, allowing the receiver to synchronize with the transmitter.

USB 3.0 (Super-Speed USB) increases the data rate to 4.8 Gbit/s, or 600 MB/s. USB 3.0 ports and cabling are designed to enable backward compatibility as well as future-proofing for optical capabilities (USB 3.0 adds fiber), although the fiber was dropped around 2007. USB 3.0 connectors contain legacy pins to interface to USB 2.0 devices, and a new set of pins for USB 3.0 connectivity (both sets reside in the same connector). Simultaneous operation of SuperSpeed and non-SuperSpeed modes is not allowed in peripheral devices. USB 3.0 devices are able to connect to either USB 3.0 or 2.0 devices, and USB 2.0 devices may connect to either USB 2.0 or 3.0 devices. The new USB 3.0 interfaces are two differential pairs, one pair for transmit and one pair for receiving data [like PCIe].

Note; the first USB 3.0 flash drive were released in 2010, but there seems to be many products by the end of 2011.
It's unknown how many USB 3.0 compatible computers have been released by the end of 2011.

{USB Bus Index}

USB Standard and Specifications

The Universal Serial Bus specification was first released in 1994.
The current USB standard, Revision 2.0 was released in 2000.
Revision 3.0 (Superspeed USB), the newest version was just released in 2008.

Extensible Host Controller Interface [xHCI] Draft Specification for USB 3.0 [09/08]
{Describes the register-level host controller interface for USB}

USB 3.0 Specification
Provides both version 3.0 and version 2.0 and 1.1 of the USB Standard

USB 2.0 Specification {USB.org}
Provides both version 2.0 and version 1.1 of the USB Standard

micro-USB Description {micro-USB description and devices}

Wireless USB description and details. USB w/ wireless access

There are two different IC USB standards; HSIC, and Inter-IC USB

{USB Bus Index}

USB 3.0 Bus Interface IC Manufacturers

This is a list of revision 3.0 USB IC Manufacturers. For revision 1.1 and 2.0 compliant IC's refer to USB 2.0

Fresco Logic
{Single-chip PCI Express to USB 3.0 host adapter, integrating a SuperSpeed PHY and a host controller conforming to eXtensible Host Controller Interface (xHCI) specification.}

Genesys Logic
{USB 3.0 host controller, in the works}

LucidPort Technology, Inc.
{Single chip USB 3.0 to SATA-II Bridge Controller with integrated USB and SATA PHYs}

Currently there are not many manufacturers that are producing USB 3.0 compliant ICs.
USB 3.0 devices are not expected until 2010, so Integrated Circuits should start showing up in late 2009.

IC Manufacturers {All other types}

{USB Interface Bus Index}

USB Pinout

The signal assignments for the Standard-A connector are shown in the pin-out table.
The Standard-B connector would reverse the Rx and Tx pins, so Rx connects to Tx.

3.0 USB Type A Connector
Super USB Connector

USB A Pinout, Cable Assembly
Pin Signal name Description Mating
1 VBUS Red Second
2 D- White Third
3 D+ Green
4 GND Black Second
5 StdA_SSRX- Blue Last
6 StdA_SSRX+ Yellow
8 StdA_SSTX- Purple
9 StdA_SSTX+ Orange
Shell Shield Connector Shell First

The five new pins were situated deeper in the connector than the legacy pins, allowing the deeper new connector to connect the extra pins,
while legacy plugs in new sockets, or new plugs in legacy sockets, would use only the original four.
The USB pinout is the same for either a type A or B connector, the difference is in the connector shape.

The pin out table also provides the mating sequence of the pins. The connector shell makes connection first.
Followed by the power [VBUS] and ground [GND] pins which make connection next.
The original USB2 pins make connection next, followed by the new pins added under the USB3 specification.

USB Powered-B Pinout, Cable Assembly
Pin Signal name Description Mating
1 VBUS Power Second
2 D- USB 2.0 Differential Pair Third
3 D+
4 GND Ground Second
5 StdA_SSTX- SuperSpeed Transmitter Pair Last
6 StdA_SSTX+
8 StdA_SSRX- SuperSpeed Receive Pair
9 StdA_SSRX+
10 DPWR Power from device
11 DGND Ground from device
Shell Shield Connector Shell First

{USB Interface Bus Index}

USB Connector Manufacturers

(Type A/B, Male/Female)

There are four different connector types: the (A/B) Jacks are used on the chassis side, and the (A/B) Plugs are used on the cable ends. Type A jacks connect to type A plugs, and type B jacks connect to type B plugs. Normally Hubs will have an A jack. Cables will have an A plug on one end an a B plug on the opposite end. The connectors have both pins 1 and 4 longer then 3 and 4, so power and ground mate first. Having the power and ground pins mate first allow devices to be Hot-Swappable. Type A connectors point to the Hub, while type B connectors point to the Function. Normally a cable will have a type A connector on the computer side [Hub] and a USB type B connector on the far [function] side, to a USB device. The cable pinout and signal names are shown in the table below [90 ohms +/-15% differential impedance]:

micro-USB Connector Manufacturers.
USB 2.0 Connector Manufacturers

ACON {USB 3.0 plugs & USB 3.0 receptacles SMT and Thru-hole or right angle connectors}

Keystone {USB 3.0 Type A/B Sockets, USB 3.0 Type A/B Plugs}

OUPIIN America Inc. {Type A, B USB Connectors}

Samtec {USB 3.0 type A socket}

Tyco Electronics {USB 3.0 I/O Connectors; Single port plug & receptacle}

Be sure you check the connector, some companies do not correctly reference the USB version, they just indicate the term USB.
So unless you know what your looking for, an older catalog will just reference USB, which may only include USB 2.0 products.
In addition I find some manufacturers placing USB3.0 products into a separate category, apart from the standard USB products.

{USB Bus Index}

USB Cable Assemblies and Adaptors

Cable cross section for USB 3.0
USB 3.0 Cable Diagram

The USB 3.0 cable contains 10 wires, unlike the 4 wire cable used with USB 2.0.
The wire gauge is not specified in the USB 3.0 standard; however there are some recommendations.
The power and ground wires should be between 20 to 28 gauge wire, and are single wires.
The original USB 2.0 data wires [D+/D-] should be between 28 to 34 wire gauge.
The four new USB 3.0 data wires should be between 26 to 34 wire gauge.
The drain wires as part of the shielded twisted pairs should range from 28 to 34 wire gauge.
A lower gauge wire should be selected when possible, and all wires are stranded.

The term SDP stands for Shielded Differential Pair, which could be a STP [Shielded Twisted Pair].
The term UTP stands for Un-shielded Twisted Pair, and matches the original standard.

Newnex Technology Corp. {USB 3.0 A to B Cable, USB 3.0 A panel mount, Bare wire.}

Be sure you check the cable, some companies do not correctly reference the USB version, they just indicate the term USB.
If the cable only has 4 wires that it's a version 2.0 cable, not a version 3.0 as shown above.

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Modified 2/4/12
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