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Preamplifier designed for current and future 2.5-inch HDDs

Allentown, PA — Agere Systems announces a new low-power preamplifier integrated circuit (IC) specifically designed for use in mobile hard disk drives (HDDs). This storage chip delivers the industry's fastest operating speeds in a low-power design, equipping notebook PCs with increased storage capacity, extended battery life, and the performance needed to serve as desktop PC replacements.

Developed specifically for 2.5-inch mobile HDDs, Agere's new TrueStore PA7700 preamplifier IC offers exceptional performance, with read/write speeds topping 1.2 gigabits-per-second (Gbits/s) while consuming half the power of previous-generation Agere chips. This chip enables higher storage capacity in disk drives and more reliable storage for PC manufacturers. Agere is delivering engineering samples of this new chip to leading HDD developers.

Industry analyst firm Gartner Dataquest expects that the number of 2.5-inch disk drives shipped globally will reach more than 96 million by 2008, with a 14 percent compound annual growth rate from 2004 to 2008. Gartner has ranked Agere No. 1 in hard disk drive semiconductors for units shipped in 2003.

“Agere is offering a preamplifier that squarely addresses the needs of laptop PCs, the highest-growth segment of the computing market,” said Joe O'Hare, vice president of Agere's Storage division. “We are delivering the outstanding speed, performance and power savings that will help PC makers accelerate the adoption of laptops as desktop PC replacements.”

The new chip enhances Agere's TrueStore electronics portfolio, which offers preamplifier solutions targeted for each segment of the computing market. This low-power preamplifier joins Agere's previously announced TrueStore PA7500, which is tailored for the desktop PC and enterprise markets.

An HDD's preamplifier is closely tied to the performance of the drive's heads and media. As a drive “reads” analog data from the disk drive platter, the preamplifier amplifies these extremely small signals before they are sent to a read-channel IC for sophisticated processing and digitization. A preamplifier is also integral to the write process by driving current through the inductive write head, which records information on the platter. Agere's new PA7700 offers the fastest data throughput available in a low-power solution, which translates to improved bit error rate performance. With Agere's chip, HDD manufacturers can increase storage capacity in higher performance 7200 RPM drives to match that of today's desktop PCs, and help transition the mobile market to next-generation areal densities.

The PA7700 writer architecture was designed to support the low-power needs of the 2.5-inch 4200 RPM power sensitive market as well as the high-performance requirements of the 2.5-inch 7200 RPM market. This architecture automatically decreases the power proportional to frequency, so extra energy is not used at lower speeds. This is accomplished without degrading the write signal integrity of the lower speed signals, resulting in increased signal-to-noise ratio performance at those data rates.

In addition to low power dissipation, Agere's PA7700 offers innovative features for optimized HDD development. The chip's bit-programmable head support allows disk drive engineers to integrate the PA7700 with either giant magneto-resistive (GMR) or tunneling GMR (TGMR) head technology. The PA7700 is also Agere's first preamplifier to support perpendicular recording, a revolutionary technique for increasing storage capacity beyond the limits of today's longitudinal recording process. Leveraging Agere's expertise in perpendicular recording for read-channels, the PA7700 can provide desktop-class switching times in perpendicular recording systems, providing increased data storage efficiency without adding excess power. With Agere's solution, HDD designers have the flexibility of using a single preamplifier across multiple drive designs and achieve superior performance regardless of what head technology or recording technique is selected.

About Agere Systems
Agere Systems is a global leader in semiconductors for storage, wireless data, and public and enterprise networks. The company's chips and software power a broad range of computing and communications applications, from cell phones, PCs, PDAs, hard disk drives and gaming devices to the world's most sophisticated wireless and wireline networks. Agere's customers include the top manufacturers of consumer electronics, communications and computing equipment. Agere's products connect people to information and entertainment at home, at work and on the road — making personal broadband a reality.

For more information, customers may visit Agere's Web site at www.agere.com or contact one of Agere's regional sales offices. Customers in the U.S. may also call the Agere Systems Customer Response Center at 1-800-372-2447. Customers in Canada may call 1-800-553-2448. Customers outside those countries may call 1-610-712-4323. Fax inquiries may be directed to 1-610-712-4106, or e-mail queries to docmaster@agere.com. Written inquiries should be sent to Agere Systems, Room 10A-301C, 1110 American Parkway NE, Lehigh Valley Central Campus, Allentown, PA, 18109, USA.

The press release points out research from Gartner Dataquest stating that the expected number of 2.5-inch disk drives shipped will reach more than 96 million by 2008, with a 14 percent compound annual growth rate from 2004 to 2008. It also shows that the company is squarely in position to support that growth. The Agere PA7700 preamplifier addresses the needs of the hard disk drive (HDD) for laptop PCs, the segment showing the highest-growth in the computing market.

The PA7700 is important because the HDD's preamplifier is closely tied to the performance of the drive's heads and disk media. As a drive “reads” analog data from the disk drive platter, the preamplifier amplifies these extremely small signals before they are sent to a read-channel IC for sophisticated processing and digitization. A preamplifier is also integral to the write process by driving current through the inductive write head, which records information on the platter.

What else is important and helps set the 7700 apart from the competition in the 2.5-inch market is the read/write speed of 1.2Gbits/s. No one else offers that speed for the low-power, 4200 rpm, 2.5-inch hard-disk drive market.

How did Agere accomplish this feat of speed and low power? Agere knew from experience what they needed to do for the next generation. The company focused on the critical cells of the design to achieve the performance needed for the recording density and data rates, and for those cells that aren't as critical the power can be dropped way down. In the desktop and high-end class performance is everything so the design did not need to go back and look at the power in a given cell. However, for this design, the Agere designers looked at the data paths all the way through for the write and read data paths. To figure out the minimum power the design initially drops the power down to less than an acceptable level and then step it back up to where it meets the performance needs and that is the power used.

Agere PA7700 block diagram
Block diagram of the Agere PA7700 preamplifier

However, this preamp also meets the requirements for both the desk top 7200 rpm and the lap top 4200 rpm drives. The 2.5″ 4200 rpm is more concerned about power consumption. The 7200 rpm market is less concerned about power and more about performance. For the 4200 rpm market the writer process was more difficult than the reader. The writer is part of the preamp that is dominant in setting the performance of the product. So this was designed so the power would scale with frequency. So if you used the part in a lower data rate (4200 rpm) application, the power would not be sacrificed, and the slew rate maintained. The slew rate is the most important part of making sure that recording is as crisp as possible for the best data rate. However, as the toggle rate goes up you need to scale power up to make sure that the higher toggle frequencies and the part is performing as needed. The design also had to consider the slew rate slew rate because it is directly proportional to power. So, there is a fine line between how much power you add and how much slew rate you get back from that power.

Another highlight is that the chip has the most flexibility of any chip on the market for 2.5″ HDDs. It supports a broad range of heads required for this market now and in the future.

This chip will get designers to the next big design move in recording and that is perpendicular recording. So this chip supports both longitudinal and perpendicular recording head technologies. As bits are recorded into the media in today's longitudinal recording they are recorded in the plane of the media, as opposed to perpendicular to the media. You can see that if you can pack the bits on end you can get a higher bit density. Presently, there are a number of challenges to perpendicular recording, and no manufacturers have announced products using perpendicular recording technology, but it's coming.

Agere says that this part will be able to cover the needs of designers for a wide range of HDD manufacturing needs. It can be used across many designs, regardless of which heads are used, the type recording (longitudinal or perpendicular) and the drive speed (4200 or 7200RPMs). All of that gives the designer a comfort zone for longevity of the preamp in their designs, now and in the future.

Agere expects to be in volume production with its low-power PA7700 preamplifier IC in early 2005. Production quantities of the desktop-level PA7500 are available now.

Go to www.agere.com for more information.

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