Dock Connector

A dock connector is a connector used to attach a mobile electronic device simultaneously to multiple external resources. The dock connector will typically carry a variety of signals and power, through a single connector, to simplify the process of docking the mobile device. A dock connector may be embedded in a mechanical fixture used to support or align the mobile device or may be at the end of a cable.

The dock connector was originally associated with laptops, but other mobile devices use the concept.

Laptop dock connector

Docking connectors for laptop computers are usually embedded into a mechanical device that supports and aligns the laptop and sports various single function ports and a power source that are aggregated into the docking connector. Early docking connectors would carry keyboard, serial, parallel, and video ports from the laptop and supply power to it. Often these ports were available on the laptop itself, giving rise to the term "port replicator" for simpler docks. More complicated docks are usually termed docking stations, but both will have some sort of docking connector. As laptop interfaces evolved, so did the functions carried by the dock connector. The keyboard and serial ports changed to PS/2 connector for the keyboard and mouse. Now, USB is almost universal and DVI is common. eSATA and FireWire ports are also carried through the docking connector.

Apple 30-pin dock connector

See also: iPod - Connectivity.

An Apple Dock Connector

The Apple dock connector is a proprietary 30-pin connector that is common on most models of iPods, and all models of the iPhone and iPad2. The iPod shuffle does not have a 30-pin dock connector.^[1] Originally, the Apple dock connector carried USB, FireWire, some controls and line-level audio outputs. As the iPod evolved, so did the signals in the dock connector. Video was added to the connector. FireWire was phased out of the iPods, which led to a discontinuity in usage of the dock connector. Older implementations of the dock connector may have been using the FireWire power pin to supply power, and cannot charge later iPods and iPhone 4s or the iPad, requiring an after market adapter to allow charging.

The simplest form of the dock connector today takes the form of a simple cable with the dock connector on one end and a USB connector on the other. This cable only has the USB signals in the dock connector, but is sufficient to synchronize and charge the devices. At the other end of the spectrum, the dock connector is used to completely merge the Apple devices into a variety of accessories, both mechanically and electrically.

Because of the popularity of Apple's iPod, many third parties have used the dock connector interface for accessories. This includes many variations of external speakers, including stereo systems and clock radios. Automotive accessories for the iPod and iPhone are numerous and include charging cradles, FM transmitters for playing audio through the car's speakers and a full GPS receiver for the iPhone. There are also original and aftermarket cables with dock connectors for direct integration with the car's audio system and controls.

An iPod dock with size 10 & 14 adapters

In the case of both Apple and third-party devices, it is often necessary that the iPod or iPhone be held upright while plugged into the device. Because this can potentially subject the 30-pin connector or corresponding port to strain and damage, an insert, specially fitted to both the Apple device and the standard connector well, is used to stabilize the connection. The adapter, a slot in which allows the dock connector access to the corresponding port on the iPhone or iPod, holds the Apple device immobile and provides a guide for safe, snug-fitting installation and extraction. Apple produces 20 different dock inserts, each fitted to the form factor of a specific device and each numbered (1 through 20) to indicate the particular model it fits.^[2]

See also

• Docking station
• PDMI, a portable device interconnection standard from CEA

Reference

1. ^ iPod Hi-Fi User guide. "Chapter 2, Step 2: Connect your iPod, page 13" (PDF). Apple.com. http://manuals.info.apple.com/en/iPod_Hi-Fi_Users_Guide.pdf. Retrieved 2007-05-25. 
2. ^ http://support.apple.com/kb/HT1380

External links

• Apple iPod, iPhone (2g, 3g), iPad dock connector pinout and interfacing
• [1]—Apple connector pinout
• [2]—Apple connector sources and specifications