Hardware - Chipsets & Electronics

Microcontroller

• iPod first to third generations — Two ARM 7TDMI-derived CPUs running at 90 MHz.

• iPod fourth and fifth generations, iPod mini, iPod nano first generation — Variable-speed ARM 7TDMI CPUs, running at a peak of 80 MHz to save battery life.

• iPod nano second generation — Samsung System-On-Chip, based around an ARM processor.

• iPod shuffle first generation — SigmaTel STMP3550 chip that handles both the music decoding and the audio circuitry.

Audio Chip

• All iPods (except the shuffle and 6G) use audio codecs developed by Wolfson Microelectronics.
• Sixth generation iPods use a Cirrus Logic audio codec chip.

Storage Medium

• iPod first to fifth generation — 45.7 mm (1.8 in) hard drives (ATA, 4200 rpm with proprietary connectors) made by Toshiba

• iPod mini — 25.4 mm (1 in) Microdrives manufactured by Hitachi and Seagate
• iPod nano — Flash memory from Samsung, Toshiba, and others.
• iPod shuffle — Flash memory

Batteries

• iPod first and second generation, nano, shuffle — Internal lithium polymer batteries
• iPod third to fifth generation — Internal lithium-ion batteries

Connectivity

Originally, a FireWire connection to the host computer was used to update songs or recharge the battery. The battery could also be charged with a power adapter that was included with the first four generations. The third generation began including a dock connector, allowing for FireWire or USB connectivity. This provided better compatibility with PCs, as most of them did not have FireWire ports at the time. However, the device could not be charged over USB, so the FireWire cables were nonetheless needed to connect to the AC adapter. The dock connector also brought opportunities to exchange data, sound and power with an iPod, which ultimately created a large market of accessories, manufactured by third parties such as Belkin and Griffin. The second generation iPod shuffle uses a single 3.5 mm jack which acts as both a headphone jack and a data port for the dock.

Two iPod wall chargers, with FireWire (left) and USB (right) connectors, which allow iPods to charge without a computer.

The iPod mini and the fourth generation iPod allowed recharging via USB and eventually Apple began shipping iPods with USB cables instead of FireWire, although the latter was available separately. As of the first generation iPod nano and the fifth generation iPod classic, Apple discontinued using FireWire for data transfer and made a full transition to USB 2.0, due to its widespread adoption. FireWire was then usable for recharging only.

iPod Dock Connector

Introduced in the third-generation iPod, the iPod's 30-pin Dock Connector allows iPods to be connected to a variety of accessories, which can range from televisions to speaker systems. Some peripherals utilize their own interface, while others use the iPod's own screen for access. Such accessories may be used for music, video, and/or photo playback. Because the Dock Connector is a proprietary interface, the implementation of the interface requires paying royalties to Apple.

Accessories

Many accessories have been made for the iPod. A large amount are made by third party companies, although many, such as iPod Hi-Fi, are made by Apple. This market is sometimes described as the iPod ecosystem. Some accessories add extra features that other music players have, such as sound recorders, FM radio tuners, wired remote controls, and audio/visual cables for TV connections. Other accessories offer more unique features like the Nike+iPod pedometer and the iPod Camera Connector. Other notable accessories include external speakers, wireless remote controls, protective cases/films and wireless earphones. Among the first accessory manufacturers were Griffin Technology, Belkin, JBL, Bose, Monster Cable, and SendStation.

( Information Source: Wikipedia )