A data storage device is disclosed comprising a first voice coil motor (VCM) comprising a first voice coil, and a second VCM comprising a second voice coil. The first VCM and the second VCM are unloaded during a power failure by measuring a first velocity and a first position of the first VCM and measuring a second velocity and a second position of the second VCM. A BEMF voltage generated by a spindle motor is used to generate a first brake voltage based on the first velocity and the first position, and the BEMF voltage is used to generate a second brake voltage based on the second velocity and the second position. The first brake voltage is applied to the first voice coil, and the second brake voltage is applied to the second voice coil.

A driver device coupled to a winding of an electro-mechanical actuator includes: a power stage driving the winding in a discontinuous mode by alternating conduction on-phases to off-phases, and a sensor circuit sensing a voltage across the winding in an off-phase, wherein, during such an off-phase the voltage across the winding includes a residual voltage which decays to zero. The power stage drives the winding from an on-phase to an off-phase by applying to the winding a reverse current pulse to invert the direction of flow of the current through the winding and produce an oscillation of the residual voltage, whereby the residual voltage includes a zero-crossing point after the current through the winding is exhausted. The sensor circuit senses the voltage across the winding at this zero-crossing point, whereby the voltage sensed across the winding at the zero-crossing point is indicative of the back electromotive force of the winding.

Disclosed herein is a magnetic storage device that includes magnetic storage discs and a first carriage arm rotatably movable in a radial direction along a first one of the magnetic storage discs and within a region radially outward from the first one of the magnetic discs. The magnetic storage device includes a first suspension arm co-movably fixed to the first carriage arm and having a first-suspension-arm length extending from a proximate first-suspension-arm end of the first suspension arm to a distal first-suspension-arm end of the first suspension arm. The magnetic storage device also includes a second suspension arm co-movably fixed to the first carriage arm and having a second-suspension arm length extending from a proximate second-suspension arm end to a distal second-suspension arm end of the second suspension arm that is different from the first-suspension arm length.

A magnetic disk device according to an embodiment includes: a magnetic disk including a plurality of tracks; a magnetic head that performs data reading and data writing on the magnetic disk; a plurality of servo regions that is provided in each of the plurality of tracks, and at least partially includes a first physical pattern, the first physical pattern being a physical pattern after writing of a first data pattern including position information of each of the plurality of tracks; and a controller that controls the magnetic head, wherein the plurality of servo regions includes one of a first servo region including the first physical pattern, and a second servo region including a second physical pattern, the second physical pattern being a physical pattern after writing of a second data pattern different from the first data pattern, for each of the plurality of tracks, and the controller performs determination as to which of the first and second physical patterns a third servo region has, the third servo region being one of a servo region among the plurality of servo regions included in the plurality of tracks.