4.7Servo Control

The actuator motor and the spindle motor are submitted to servo control. The actuator motor is controlled for moving and positioning the head to the track containing the desired data. To turn the disk at a constant velocity, the actuator motor is controlled according to the servo data that is written on the data side beforehand.

4.7.1Servo control circuit

Figure 4.4 is the block diagram of the servo control circuit. The following describes the functions of the blocks:

(1)

 

 

 

 

 

 

 

 

 

 

MPU

 

 

(2)

 

 

(3)

 

 

 

 

 

 

Servo

 

 

 

 

ADC

 

DSP

 

Head

 

 

burst

 

 

 

 

 

 

 

 

 

 

 

 

 

unit

 

 

 

 

capture

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Position Sense

 

 

 

CSR: Current Sense Resistor

VCM: Voice Coil Motor

SVC

 

(4)

(5)

VCM current

 

P.

DAC

 

Amp.

 

 

 

 

 

CSR

 

 

VCM

(6)

(7)

 

Spindle

Driver

Spindle

motor

motor

control

 

 

 

Figure 4.4 Block diagram of servo control circuit

(1)Microprocessor unit (MPU)

The MPU includes DSP unit, etc., and the MPU starts the spindle motor, moves the heads to the reference cylinders, seeks the specified cylinder, and executes calibration according to the internal operations of the MPU.

The major internal operations are listed below.

a.Spindle motor start

Starts the spindle motor and accelerates it to normal speed when power is applied.

4 - 14

C141-E077-01EN

Page 59
Image 59
Fujitsu MPE3XXXAT manual Servo control circuit

MPE3XXXAT specifications

The Fujitsu MPE3XXXAT series is a robust line of hard disk drives (HDDs) known for their reliability, performance, and advanced technology. Designed primarily for enterprise storage solutions, these drives cater to high-demand environments such as data centers, servers, and workstations. With capacities ranging from hundreds of gigabytes to several terabytes, the MPE3XXXAT series offers scalable storage options to accommodate a variety of applications.

One of the standout features of the MPE3XXXAT series is its high rotational speed. With most models operating at 7200 RPM, these drives ensure faster data access and improved read/write performance. This speed makes them ideal for applications requiring quick data retrieval, such as database management and data-intensive workloads. Furthermore, the series utilizes a Serial ATA (SATA) interface, which facilitates seamless connectivity and compatibility with a wide range of systems.

The Fujitsu MPE3XXXAT series is built with advanced technologies that enhance durability and longevity. Notably, the drives incorporate advanced error correction algorithms and vibration resistance features, which are crucial for maintaining data integrity over time. This is particularly important in multi-drive environments where vibrations from one drive can affect the performance of others. The drives are also designed with low power consumption in mind, contributing to energy savings without compromising performance.

In terms of data security, the MPE3XXXAT series supports various security features that protect against unauthorized access. These include ATA security features that enable password protection and robust encryption to safeguard sensitive information from potential breaches. This aspect is particularly significant for enterprises that handle confidential data and require stringent security measures.

The operational temperature range of the MPE3XXXAT drives is optimized for demanding environments, allowing them to function effectively in a variety of conditions. Their reliability is backed by an impressive Mean Time Between Failures (MTBF), which signifies their resilience and the manufacturer's commitment to quality.

Overall, the Fujitsu MPE3XXXAT series stands out as a reliable choice for enterprise storage needs. With its blend of high speed, capacity, durability, and security features, it addresses the challenges faced by modern data centers and businesses that require efficient data management solutions. Whether for backup, archival, or active data storage, the MPE3XXXAT series is designed to deliver consistent performance and peace of mind for users.