Abstract: To provide a disk drive capable of inhibiting the occurrence of acoustic noise caused by a voltage pulse when the head is retracted using a speed control method using voltage obtained by rectifying a back electromotive force after the power source has been cut off from the rotation of a spindle motor. Retraction control circuit is used to control the on and off modes of transistors in accordance with the speed of VCM. The voltage across VCM becomes a voltage that can be regulated with VCM voltage control circuit. At this time, voltage is supplied to the terminals based on the voltage of ISO5V that is the rectified voltage of the back electromotive force of the spindle motor and the pulsating voltage is synchronized and produced at both terminals. As a result, the potential difference across VCM is such that the pulsating voltage is negated and acoustic noise is inhibited.

Abstract: The objective of this invention is to provide a motor control device, and a disk drive device using the same, in which during emergency operation it is possible to supply necessary power to the motor while limiting enlargement of the circuit area. During the retraction operation, control is performed to alternate between a short-circuit mode in which each terminal U, V, W of the spindle motor M1 is short-circuited to the terminal ICOM, and a rectifying mode in which the back electromotive force of the spindle motor M1 is rectifies and output to the power supply line ISO3V, VGND while the input of power from the power supply line ISO3V, VGND to the spindle motor M1 is blocked.

Abstract: A disk drive system including retract logic for control of the voice coil motor in a retract operation, in which the voice coil motor positions the read/write head actuator arm in a safe place in a loss-of-power event, is disclosed. The retract logic includes circuitry for controlling the application of power to the voice coil motor from an external capacitor, so that a constant voltage is maintained across the voice coil motor. Current from the capacitor is directed to an internal variable resistor that conducts a selected current, in parallel with the current applied to the voice coil motor. The voltage developed across the variable resistor is applied to one input of a control amplifier, which receives the voltage across the voice coil motor at another input; the control amplifier in turn controls the gate of a low side transistor. The transistor passes current to the extent that the voltage across the voice coil motor corresponds to that developed across the variable resistor.

Abstract: The objective of this invention is to provide a motor control device, and a disk drive device using the same, in which during emergency operation it is possible to supply necessary power to the motor while limiting enlargement of the circuit area. During the retraction operation, control is performed to alternate between a short-circuit mode in which each terminal U, V, W of the spindle motor Ml is short-circuited to the terminal ICOM, and a rectifying mode in which the back electromotive force of the spindle motor M1 is rectifies and output to the power supply line ISO3V, VGND while the input of power from the power supply line ISO3V, VGND to the spindle motor M1 is blocked.

Abstract: To provide a disk drive capable of inhibiting the occurrence of acoustic noise caused by a voltage pulse when the head is retracted using a speed control method using voltage obtained by rectifying a back electromotive force after the power source has been cut off from the rotation of a spindle motor. Retraction control circuit is used to control the on and off modes of transistors in accordance with the speed of VCM. The voltage across VCM becomes a voltage that can be regulated with VCM voltage control circuit. At this time, voltage is supplied to the terminals based on the voltage of ISO5V that is the rectified voltage of the back electromotive force of the spindle motor and the pulsating voltage is synchronized and produced at both terminals. As a result, the potential difference across VCM is such that the pulsating voltage is negated and acoustic noise is inhibited.

Abstract: One embodiment of the invention includes a voice coil motor (VCM) drive system. The system includes a VCM configured to move a read/write head across a magnetic disk in response to a current flow through the VCM. The system also includes a VCM output stage configured to direct the current through the VCM in one of a first direction corresponding to retraction of the read/write head and a second direction corresponding to extension of the read/write head in response to switching control signals. The system further includes a retract controller configured to control a retraction velocity of the read/write head by generating the switching control signals to provide the current in the first direction to increase the retraction velocity of the read/write head and to provide the current in the second direction to decrease the retraction velocity of the read/write head during a retraction mode of the VCM drive system.

Abstract: A disk drive system including retract logic for control of the voice coil motor in a retract operation, in which the voice coil motor positions the read/write head actuator arm in a safe place in a loss-of-power event, is disclosed. The retract logic includes circuitry for controlling the application of power to the voice coil motor from an external capacitor in a pulse-width modulated manner. Current from the capacitor is coupled to the voice coil motor in a drive phase of the pulse-width modulation cycle, and is recirculated through the voice coil motor in a complementary phase of the pulse-width modulation cycle. The recirculation is accomplished by a recirculation transistor that is smaller than the pull-down transistor used in the drive phase.

Abstract: A disk drive system including retract logic for control of the voice coil motor in a retract operation, in which the voice coil motor positions the read/write head actuator arm in a safe place in a loss-of-power event, is disclosed. The retract logic includes circuitry for controlling the application of power to the voice coil motor from an external capacitor in a pulse-width modulated manner. Current from the capacitor is coupled to the voice coil motor in a drive phase of the pulse-width modulation cycle, and is recirculated through the voice coil motor in a complementary phase of the pulse-width modulation cycle. The recirculation is accomplished by a recirculation transistor that is smaller than the pull-down transistor used in the drive phase.

Abstract: A disk drive system including retract logic for control of the voice coil motor in a retract operation, in which the voice coil motor positions the read/write head actuator arm in a safe place in a loss-of-power event, is disclosed. The retract logic includes circuitry for controlling the application of power to the voice coil motor from an external capacitor, so that a constant voltage is maintained across the voice coil motor. Current from the capacitor is directed to an internal variable resistor that conducts a selected current, in parallel with the current applied to the voice coil motor. The voltage developed across the variable resistor is applied to one input of a control amplifier, which receives the voltage across the voice coil motor at another input; the control amplifier in turn controls the gate of a low side transistor. The transistor passes current to the extent that the voltage across the voice coil motor corresponds to that developed across the variable resistor.

Abstract: A disk drive actuator circuit adapted to retract a head assembly when a capacitor discharges energy to the voice coil. This voltage may be modulated to deliver peak torque to get the actuator over a ramp, yet also deliver a lower torque to suppress the initial head velocity when the actuator is over the disk.