4.7 Servo Control

(6) Driver circuit

The driver circuit is a power amplitude circuit that receives signals from the spindle motor control circuit and feeds currents to the spindle motor.

(7) VCM current sense resistor (CSR)

This resistor controls current at the power amplifier by converting the VCM current into voltage and feeding back.

4.7.2 Data-surface servo format

Figure 4.7 describes the physical layout of the servo frame. The three areas indicated by (1) to (3) in Figure 4.7 are described below.

(1) Inner guard band

This area is located inside the user area, and the rotational speed of the VCM can be controlled on this cylinder area for head moving.

(2) Data area

This area is used as the user data area and SA area.

(3) Outer guard band

This area is located at outer position of the user data area, and the rotational speed of the spindle can be controlled on this cylinder area for head moving.

C141-E249

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Fujitsu MHW2060BS, MHW2100BS, MHW2080BS, MHW2120BS, MHW2040BS manual Data-surface servo format