Power failure management in disk drives
AssigneeWestern Digital Technologies, Inc.
InventorsTIMOTHY A. FERRIS, ROBERT P. RYAN
Life of this patent
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Abstract
A disk drive is disclosed comprising a disk, a spindle motor operable to rotate the disk, a head actuated over the disk, an interface operable to receive a host supply voltage, and a capacitor. The host supply voltage is used to charge the capacitor to a capacitor voltage higher than the host supply voltage. During a power failure, the host supply voltage stops charging the capacitor, and a motor supply voltage is generated from the spindle motor. The capacitor voltage is used to operate control circuitry, and when the capacitor voltage decays below the motor supply voltage, the motor supply voltage charges the capacitor.
Claims29
A disk drive comprising:
- a disk;
- a spindle motor operable to rotate the disk;
- an interface configured to receive a host supply voltage;
- a power storage device;
- and
- control circuitry configured to:
- use the host supply voltage to charge the power storage device;
- and
- during a power failure:
- stop charging the power storage device using the host supply voltage;
- generate a motor supply voltage from the spindle motor;
- use power from the power storage device to write a first portion of host data associated with a pending write operation to the disk;
- compare a voltage level of the power storage device to the motor supply voltage to determine when the voltage level of the power storage device becomes less than the motor supply voltage;
- re-charge the power storage device using the motor supply voltage when it is determined that the voltage level of the power storage device has become less than the motor supply voltage;
- and
- write a second portion of the host data to the disk using the re-charged power storage device.
A disk drive comprising:
- a disk;
- a head configured to write data to the disk;
- a microactuator configured to actuate the head;
- an interface operable to receive a host supply voltage;
- a power storage device configured to store a backup voltage;
- a voltage booster configured to receive the host supply voltage at an input and generate a boosted host supply voltage;
- and
- control circuitry configured to, in response to a power failure event:
- disconnect the voltage booster input from the host supply voltage and connect the voltage booster input to the backup voltage;
- generate a boosted backup voltage using the voltage booster;
- and
- power the microactuator using the boosted backup voltage.
A device comprising:
- control circuitry configured to:
- use a host supply voltage received via an interface to charge a power storage device;
- and
- during a power failure:
- stop charging the power storage device using the host supply voltage;
- generate a motor supply voltage from a spindle motor operable to rotate a disk;
- use power from the power storage device to write a first portion of host data associated with a pending write operation to the disk;
- compare a voltage level of the power storage device to the motor supply voltage to determine when the voltage level of the power storage device becomes less than the motor supply voltage;
- re-charge the power storage device using the motor supply voltage when it is determined that the voltage level of the power storage device has become less than the motor supply voltage;
- and
- write a second portion of the host data to the disk using the re-charged power storage device.
Dependencies are inferred from the claim text.