Patent ID: 7872824

Claim:
A disk drive comprising: a disk; a head actuated over the disk, the head comprising a magnetoresistive (MR) element; and control circuitry operable to set an operating bias current for the MR element by: computing a target voltage for the MR element; applying a bias current to the MR element; measuring a voltage across the MR element corresponding to the bias current; and adjusting the bias current applied to the MR element until the measured voltage substantially equals the target voltage, wherein the control circuitry computes the target voltage using a function comprising a DC offset, and the control circuitry is further operable to set the operating bias current for the MR element by: determining a first DC offset of the function corresponding to a first ambient temperature; determining a second DC offset of the function corresponding to a second ambient temperature; measuring an ambient temperature of the disk drive; and adjusting the DC offset of the function in response to the first DC offset, the second DC offset, and the measured ambient temperature.