TEXAS A&M UNIVERSITY
Department of Electrical and Computer Engineer ing
Co l le g e S ta tio n, T exa s 7 7 8 4 3 -3 1 2 8
T EL ( 4 0 9 ) 8 4 5 -7 4 9 8 F AX (4 0 9 ) 8 4 5 -7 1 6 1
sa nc h ez @e ce. ta mu . ed u
ht tp : // a me sp 0 2 . ta mu . ed u
Room 227A ZEC
Thursday, November 15, 2007 3:55 - 5:10 P.M.
From Multi-Gb/s RAID Servers to Ultra Lpw Power iPods:
AFE Ckt Design Techniques for the HDD Industry
Texas Instruments, Inc.
Abstract: Preamplifier is a widely used AFE chip in the Hard Disk Drive application.
With the growing demand of Storage devices, high capacity and faster access times are
becoming critical functions of hard drives. This translates to very high data rate
requirements for Preamplifiers > 3 to 4Gbps. Very high speed Read amplifiers and ultra
fast Write Drivers are the key elements of this ASIC. Key challenges include Wide-Band,
Low-Noise Amplifier within a Very Non-Ideal Environment, Lossy Input/Out interconnect
possess many discontinuities. Furthermore challenging is a very high speed Write driver
which transfers NRZ (digital) data to the magnetic media by switching current through the
inductive write head. Since the preamp is the only electronic device within the drive
enclosure, it also provides test (aka measurement & fault) circuitry to ensure the read/write
heads, Magnetic media, the fly height over media, power supplies, etc are manufactured
and connected properly. Power Consumption is another critical factor in preamp design as
low power mobile applications (MP3s, Still/Video Cameras, Laptops, etc) are battery operated
and thus sensitive to power consumption.
Pankaj Pandey received the Bachelor of Engineering degree from Regional Engineering College
Surat, India in 1998 and the M.S. degree from Texas A&M University, College Station in 2003. He
then joined the Storage Product Group of Texas Instruments, Dallas TX as a Mixed-Signal Design
Engineer, and is currently designing next-generation preamplifiers for the hard-disk-drive industry.
His research interests include high-speed continuous time filters, adaptive tuning schemes, signal
processing, and write coil drivers and high speed H-bridges.