FUJITSU MAY2073RC - Manual (Page 21)

1.1 Standard Features
C141-E230 1-5
1.2 Hardware Structure
The HDDs have a disk enclosure (DE) and a printed circuit assembly (PCA). The DE includes heads
on an actuator and disks on a spindle motor mounted on the DE. The PCA 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 MEEPR4ML (Modified Enhanced Extended Partial Response Class 4 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.