Interleaved analog tracking timing and gain feedback loops for partial response maximum likelihood (PRML) data detection for direct access storage device (DASD)

摘要

A high speed analog timing and gain feedback control methods and a low power analog tracking timing and gain feedback apparatus are provided for data detection, such as, partial-response maximum- likelihood (PRML) data detection in a direct access storage device (DASD). The interleaved gain and timing tracking control circuit includes an even interleave gain and timing tracking control providing an even interleave gain error signal and an even interleave timing error signal; and an odd interleave gain and timing tracking control providing an odd interleave gain error signal and an odd interleave timing error signal. The even interleave gain error signal and the odd interleave gain error signal are combined to provide a resulting gain control signal. The even interleave timing error signal and the odd interleave timing error signal are combined to provide a resulting timing control signal. The resulting gain control signal is applied to a variable gain amplifier and the resulting timing control signal is applied to a variable clock circuit in a data channel of a direct access storage device (DASD).