Disk drive servo arm retract and spindle brake circuit

• US 6,819,072 B2
• Filed: 03/26/2001
• Issued: 11/16/2004
• Est. Priority Date: 12/18/2000
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: White, Bertram J., Ziemer, Kevin W.
• Primary Examiner(s): Martin, David
• Assistant Examiner(s): SMITH, TYRONE W
• Application Number:
  US09/817,695
• Publication Number:
  US 20020074963A1
• Time in Patent Office: 1,331 Days
• Field of Search: 318/739, 318/254, 318/438, 318/439, 318/603, 318/798, 318/812, 318/270, 318/560, 360/74.1, 360/75, 360/78.04, 360/73-1-
• US Class Current: 318/560
• CPC Class Codes: G11B 19/22 Brakes other than speed-regulating brakes
• CPC Class Codes: G11B 21/12 Raising and lowering; Back-spacing or forward-spacing along track; Returning to starting position otherwise than during transducing operation

Abstract

A spindle motor control circuit for controlling a motor; including a control circuit to control the motor during at least a low state, a pulse state and a high state, the motor braking during said low state, the control circuit receiving a flyback voltage from the motor during the pulse state and the control circuit receiving a reduced flyback voltage from the motor during the high state.

Claims

1. A spindle motor control circuit for controlling a motor;

comprising;

a control circuit to control said motor during at least a low voltage state, a pulse voltage state and a high voltage state;

said motor braking during said low voltage state;

said control circuit receiving a flyback voltage from said motor during said pulse voltage state;

said control circuit receiving a reduced flyback voltage being smaller than said flyback voltage from said motor during said high voltage state.

2. A spindle motor control circuit for controlling a motor, as in claim 1, wherein said control circuit includes an op amp to feed back a voltage to limit said flyback voltage from said motor.

3. A spindle motor control circuit for controlling a motor, as in claim 1, wherein said voltage is a first voltage during said pulse voltage state and a second voltage during said high voltage state.

4. A spindle motor control circuit for controlling a motor, as in claim 3, wherein said first voltage is greater than said second voltage.

5. A spindle motor control circuit for controlling a motor, as in claim 1, wherein said motor is braked before said pulse voltage state and after said high voltage state.