Patent ID: 8611036

Claim:
A magnetic recording disk drive comprising: a rotatable magnetic recording disk having a plurality of generally concentric data tracks and a plurality of angularly-spaced servo sectors having servo identification (SID) marks extending generally radially across the tracks; an air-bearing slider maintained near the surface of the disk when the disk is rotating; a write head on the slider for writing data in the data tracks of the disk, the write head including an electrical coil for receipt of write current; a read head on the slider for reading data in the data tracks of the disk, the read head being capable of detecting SID marks during rotation of the disk; a heater on the slider for changing the spacing between the heads and the disk; a data controller coupled to the head for controlling the reading and writing of data; a head fly-height controller (FHC) coupled to the data controller and the heater for applying power to the heater to change the spacing, the FHC including a digital-to-analog converter (DAC) for converting a digital heater power value (HPV) to an analog output voltage to the heater, the FHC including logic for undertaking method acts of: during reading of data, inputting to the DAC a HPV corresponding to the desired read head fly-height (Read-HPV); and during writing, for each SID commencing with the SID at initiation of writing, inputting to the DAC a successively reduced HPV, wherein each HPV is a HPV reduced according to an exponential relationship; and terminating the inputting of HPVs when the desired write head fly-height is achieved.