Hard-disk drive read-channel design trade-offs for areal densities beyond 2 Tb/in2

Abstract

Due to the ever-increasing recording densities, disk-drive read channels are required to operate efficiently at high speeds. With the use of conventional design techniques, a compromise should be made between speed, power, latency and chip area. Improvements of head and media technology and the move from conventional single-track magnetic recording to two-dimensional magnetic recording help increase the areal density of magnetic data storage. Especially for the read channel, a performance gain is achieved by using more powerful coding and signal processing algorithms to mitigate inter-symbol and inter-track interferences. Timing recovery is essential to extract timing information in order to sample read data without a significant bit error, while calibration is performed to cancel the effects of gain and dc offset errors. Speed improvement and power consumption diminution are achieved in the resulting read channel system by using high-speed and power-efficient building blocks based on improved algorithms and pipeline stages to shorten critical paths.