A spin transfer torque reversal assisted magnetic recording (STRAMR) structure is disclosed wherein two flux change layers (FCL1 and FCL2) are formed within a write gap (WG) and between a main pole (MP) trailing side and trailing shield (TS). Each FCL has a magnetization that flips to a direction substantially opposing a WG field when a direct current of sufficient current density is applied across the STRAMR device thereby increasing reluctance in the WG and producing a larger write field output at the air bearing surface. A reference layer (RL1) is used to reflect spin polarized electrons that exert spin torque on FCL1 and cause FCL1 magnetization to flip. A second reference layer (or the MP or TS) is employed to reflect spin polarize electrons that generate spin torque on FCL2 and flip FCL2 magnetization. Non-spin polarization preserving layers and spin polarization preserving layers are also in the STRAMR structure.

The half-bridges driving a multiphase motor are controlled to perform a sequence of operations to support charging a hold capacitor. First, in a brake configuration, the half-bridge transistors are controlled such that either high-side transistors or low-side transistors of the half-bridges are turned on. Second, in an active step-up configuration, the half-bridge transistors are controlled such that the high-side transistor of a first half-bridge and the low-side transistor of a second half-bridge are both turned on and the low-side transistor of the first half-bridge and the high-side transistor of the second half-bridge are both turned off. Third, in an active brake configuration, the half-bridge transistors are controlled such that the low-side transistor of the first half-bridge and the high-side transistor of the second half-bridge are both turned on and the high-side transistor of the first half-bridge and the low-side transistor of the second half-bridge stage are both turned off.

A spindle motor includes a rotating part, a base member, a connector, and a connector accommodating recess in the base member. The connector accommodating recess includes a bottom surface and an annular wall surface extending from the bottom surface to the outer surface. A through-hole is formed in the bottom surface. The bottom surface includes a first annular surface extending toward the annular wall surface from a peripheral edge of the through-hole, and a second annular surface extending around the first annular surface on an axial outer surface side of the base member relatively to the first annular surface. The connector contacts the second annular surface. A first gap between the connector and the first annular surface is filled with an adhesive. An interface of the adhesive extends i to protrude from an inner peripheral surface of the through-hole over an entire circumference of the through-hole.

A slider design for a hard disk drive (HDD) features a shallow cavity adjacent to a leading edge that has patterns of sub-cavities of various shapes etched into its base to reduce its original surface area. The presence of these patterns of sub-cavities significantly reduces the probability that the slider will capture particles on the surface of a rotating disk and thereby reduces the corresponding probability of surface scratches that such captured particles inevitably produce.

A motor includes a shaft, a bearing that rotatably supports the shaft, and a hub fixed to the shaft. The shaft includes a first shaft portion extending in an axial direction, a second shaft portion projecting axially upward from an axially upper end surface of the first shaft portion and including a diameter smaller than that of the first shaft portion, and a screw hole recessed axially downward from the axially upper end surface. The hub includes a shaft fixing hole into and in which the second shaft portion is inserted and fixed. An outer surface of the second shaft portion includes a first region, and a second region axially above the first region, and including surface roughness smaller than that of the first region.

A mobile drive unit includes a turntable and a turntable motor that is located outside of the footprint of the turntable. The motor moves up and down with the turntable such that a motor cover moves up and down with the turntable.

Disclosed herein is an amplification circuit that outputs an output signal formed by amplifying a differential signal between a first input terminal and a second input terminal using an operating amplifier and a plurality of resistors, the amplification circuit including an adjustment circuit configured to adjust a frequency property of the output signal for an in-phase alternating current signal input between the first input terminal and the second input terminal. The adjustment circuit is connected to one input terminal of the first input terminal and the second input terminal through one or more resistors, the adjustment circuit includes a capacitor part whose capacitance is set to be variable, and the adjustment is realized through variable setting of the capacitance of the capacitor part.

A slider design for a hard disk drive (HDD) features a shallow cavity adjacent to a leading edge that has patterns of sub-cavities of various shapes etched into its base to reduce its original surface area. The presence of these patterns of sub-cavities significantly reduces the probability that the slider will capture particles on the surface of a rotating disk and thereby reduces the corresponding probability of surface scratches that such captured particles inevitably produce.

An apparatus, according to one embodiment, includes: a support plate, a stator, a rotor sub-assembly, and at least one isolation mount coupled between the support plate and the stator. The isolation mount is for reducing transfer of vibration from the stator to the support plate. Moreover, the stator is coplanar with the support plate. The rotor sub-assembly includes a magnet, and a hub rotatably fixed relative to the magnet. The rotor sub-assembly is also configured to rotate relative to the support plate and the stator. Other systems, methods, and computer program products are described in additional embodiments.

An apparatus, according to one embodiment, includes: a support plate, a stator, and a stator support arm. The stator support arm has a first end that is coupled to the support plate, and extends from the support plate to the stator. Moreover, the stator is coplanar with the support plate. The apparatus further includes at least one isolation mount, and a rotor sub-assembly. The isolation mount is coupled between a second end of the stator support arm and the stator for reducing transfer of vibration from the stator to the stator support arm. The rotor sub-assembly includes a magnet, and a hub rotatably fixed relative to the magnet. Furthermore, the rotor sub-assembly is configured to rotate relative to the support plate and the stator. Other systems, methods, and computer program products are described in additional embodiments.