201305.pdf 43279KB May 08 2013 11:07:04 PM

Three banks of plastichousings contain two LEDseach, with light guided tothe front of the drive.Battery backupThe LSI TruePHY ET1011C2-CGigabit Ethernet transceiver debutedin 2008. It’s built on 0.13-μmtechnology and is fully compliantwith IEEE 802.3, 802.3u, and802.3ab standards. Its main claim tofame is its use of an oversamplingarchitecture to improve equalization.Power-on button on rear, followeddown the back by USB, Ethernet,reset, and power inThree storage platters (These, and the read heads, have come a longway in the past 20 years. For more on modern storage techniques,including giant magnetoresistance all the way up to spintronics andquantum bits, take a look at this summary: http://bit.ly/Zg7yiW.)Read-head armaturein rest position (Thearmature is driven bythe voice coil actuatoron the left, housedbetween nickel-platedneodymium magnets,the most powerfulpermanent magnetsavailable today.)Coil and neodymiummagnet housing (Coil isheld between an upperand lower magnet witha four-wire interfaceto/from the SMOOTHL7251 to control read/write head position andacquire data.)The Oxford SemiconductorOXE810DSE (now the PLX810,since PLX Tech acquired Oxford)is a Gigabit Ethernet to dual SATAcontroller. It is the main interface IC,with 802.11 support via Mini PCI.It has since been discontinued andreplaced by the NAS 7821. BrianDipert spent some time on the PLXchip in his teardown of an olderWD NAS drive back in 2010 (www.edn.com/4312333). Also shown:1 Gbyte of DDR2 memory (HynixHY5PS1G1631C)Over the years, fundamentalresearch into electromagnets,quantum principles, materials,channel equalization, and motorcontroland -positioning algorithmshas been embodied within thesedrives. It’s more than can even betouched on in a short teardown piece,yet we can take these drives so muchfor granted. As always, I’ll be holdingonto the parts, much like I do a goodbook. So much thought, research, andingenuity have gone into realizingthe product that throwing it out isactually hard to do, though I can onlyhoard so much until my wife gives me“that look.”[ www.edn.com]MAY 2013 | EDN 23