Patent ID: 7619841

Claim:
A disk drive comprising: (a) a disk comprising a plurality of data tracks, wherein: each data track comprises a plurality of data sectors and a plurality of servo sectors; and each servo sector comprises a plurality of servo bursts; (b) a head actuated over the disk operable to read the data sectors and servo sectors to generate read signals; (c) a data path comprising a data decoder operable to decode a data read signal generated as the head passes over the data sectors; and (d) a servo path comprising: a low pass filter operable to extract a low frequency component from a servo read signal generated as the head passes over the servo bursts, wherein the low pass filter does not operate on the data read signal; a subtractor operable to subtract the low frequency component from the servo read signal to generate a servo burst signal; a servo demodulator operable to demodulate the servo burst signal; and a servo burst window signal operable to enable the low pass filter and subtractor as the head passes over the servo bursts.