According to one embodiment, curve fitting, which uses power supplied to the thermal actuator when a magnetic head is brought into contact with a magnetic disk by the thermal actuator and a quadratic or higher curve, is performed at at least five radial positions in a radial direction of the magnetic disk in a case of setting a control value of the thermal actuator, and it is determined as abnormal contact detection when a Z value of an RMS of a fitting residual from the quadratic or higher curve of each power exceeds a predetermined value.

A data storage device is disclosed comprising a first head actuated over a first disk surface, the first head comprising a plurality of elements including a first element. During a first write operation of the first head, a first bias signal having a first polarity is applied to the first element, and a write interval of the first write operation is measured. During a non-write mode of the first head, a second bias signal having a second polarity opposite the first polarity is applied to the first element during a reverse bias interval that is based on the write interval of the first write operation.

According to one embodiment, curve fitting, which uses power supplied to the thermal actuator when a magnetic head is brought into contact with a magnetic disk by the thermal actuator and a quadratic or higher curve, is performed at at least five radial positions in a radial direction of the magnetic disk in a case of setting a control value of the thermal actuator, and it is determined as abnormal contact detection when a Z value of an RMS of a fitting residual from the quadratic or higher curve of each power exceeds a predetermined value.

The present invention is directed to the fabrication of head sliders for use in hard disk drives, and in particular the provision and usage of electrical bond pads on the slider surface structure to accommodate needs of the fabrication process as well as slider operation within a disk drive.

Various illustrative aspects are directed to a data storage device comprising a slider with a resistive temperature detector with a first resistance, a resistance detection circuit electrically coupled to the first resistance and comprising a low and high frequency path corresponding to a DC and AC mode, respectively, and one or more processing devices configured to: bias the first resistance with a voltage bias, where the first resistance is coupled to a first and second amplifier, control a pulse generator to add a bias pulse on the HF path to generate a HF resistance detection signal, where the second amplifier is biased using the voltage bias and the bias pulse, control a clock to chop a LF signal at the first amplifier on the LF path, demodulate the chopped LF signal to generate a LF resistance detection signal, and concurrently process the HF and LF resistance detection signals.

The present invention is directed to the fabrication of head sliders for use in hard disk drives, and in particular the provision and usage of electrical bond pads on the slider surface structure to accommodate needs of the fabrication process as well as slider operation within a disk drive.

According to one embodiment, a magnetic disk drive selects in command evaluation in reordering processing, a command accessible in a shortest time. The device determines whether media bumps which influence a dynamic flying height (DFH) control exist in a seek section between completion of a previous command and start of a selected command or not, calculates a latency necessary for avoidance of the media bumps if it is determined by the determination that the media bumps which influence the DFH control exist, and selects the command accessible in the shortest time including the time obtained by summing the latency calculated by the calculation as the command to be next processed.

A data storage device is disclosed comprising a first head actuated over a first disk surface, the first head comprising a plurality of elements including a first element. During a first write operation of the first head, a first bias signal having a first polarity is applied to the first element, and a write interval of the first write operation is measured. During a non-write mode of the first head, a second bias signal having a second polarity opposite the first polarity is applied to the first element during a reverse bias interval that is based on the write interval of the first write operation.

A method is disclosed for establishing a fly height parameter for a hard disc drive. The method includes receiving a set of testing data associated with the hard disc drive and subjecting the hard disc drive to a fly-height test at a first, nominal temperature to generate fly-height data. Based on the set of testing data and the fly-height data, the method includes predicting the hard disc drive's fly-height data for a fly-height test at a second temperature different from the first, nominal temperature. The method further includes establishing the fly-height parameter for the hard disc drive in response to the fly-height data and the predicted fly-height data.

According to one embodiment, a magnetic disk drive selects in command evaluation in reordering processing, a command accessible in a shortest time. The device determines whether media bumps which influence a dynamic flying height (DFH) control exist in a seek section between completion of a previous command and start of a selected command or not, calculates a latency necessary for avoidance of the media bumps if it is determined by the determination that the media bumps which influence the DFH control exist, and selects the command accessible in the shortest time including the time obtained by summing the latency calculated by the calculation as the command to be next processed.