Fujitsu MBB2147RC 用户手册

 
1.2 Hardware 

 

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. 

 
 

C141-E257 

17