Hard disk drive read channels: technology and trends

Advances in read channel technology over the past 8 years have contributed approximately 50% to the areal density growth in magnetic hard disk drive (HDD) systems. This paper provides an overview of HDD read channel technology and trends. Dominant channel impairments are discussed along with signal processing methods to mitigate their effects. Equalization and coding techniques, capable of achieving higher areal densities, are reviewed. Finally, circuit design challenges in meeting the emerging data rate requirement of 1 Gb/s in read channel products are discussed.