Fujitsu MBB2073RC, MBB2147RC manual Hardware Structure

1.2 Hardware Structure

1.2Hardware Structure

The HDDs have a disk enclosure (DE) and a printed circuit board assembly (PCBA). The DE includes heads on an actuator and disks on a spindle motor mounted on the DE. The PCBA includes a read/write circuit and a controller circuit.

(1)Disks

The disks have an outer diameter of 65 mm (2.56 inch).

(2)Heads

The heads have MR (Magnet-Resistive) read element Ramp Load type slider.

(3)Spindle motor

The disks are rotated by a direct-drive hall-less DC spindle motor. The motor speed is controlled by a feedback circuit using the counter electromotive current to precisely maintain the specified speed.

(4)Actuator

The actuator, which uses a rotary voice coil motor (VCM), consumes little power and generates little heat. The heads at the end of the actuator arm are controlled and positioned via feedback servo loop.

The heads are positioned on the ramp when the power is off or the spindle motor is stopped.

(5)Read/write circuit

The read/write circuit utilizes a read channel mounted with a head IC that supports high-speed transmission and an MEEPRML (Modified Enhanced Extended Partial Response Maximum Likelihood) modulation/demodulation circuit in order to prevent errors being triggered by external noise and to improve data reliability.

(6)Controller circuit

The controller circuit uses LSIs to increase the reliability and uses a high speed microprocessing unit (MPU) to increase the performance of the SAS controller.

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