Data storage device with overvoltage protection

Patent metadata

Field	Value
Publication number	US-9251839-B1
Application number	US-201314040426-A
Country	US
Kind code	B1
Filing date	Sep 27, 2013
Priority date	May 24, 2013
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

A data storage device coupled to a host power supply is disclosed and includes a spindle motor and Voice Coil Motor (VCM) circuitry, a power device coupled to the host power supply via a first host supply line and coupled to the spindle motor and VCM circuitry, wherein the power device comprises a first voltage rail, a first isolation circuit, and control circuitry, wherein the power device receives a first supply voltage on the first voltage rail via the first host supply line and provides the first supply voltage to the spindle motor and VCM circuitry via the first isolation circuit, and wherein the control circuitry is operable to monitor the first voltage rail for an overvoltage event and, when the overvoltage event is detected, control the first isolation circuit to disconnect the spindle motor and VCM circuitry from the first voltage rail.

First claim

What is claimed is:

1. A data storage device comprising:
spindle motor circuitry;
Voice Coil Motor (VCM) circuitry;
a power device coupled to a host power supply via first and second host supply lines and coupled to the spindle motor circuitry and the VCM circuitry, the power device comprising:
first and second voltage rails;
a first isolation circuit; and
control circuitry;

a second isolation circuit coupled to the second host supply line between the host power supply and the power device; and
a third isolation circuit coupled to the first host supply line between the host power supply and the power device;
wherein the power device is operable to receive a first supply voltage on the first voltage rail via the first host supply line and provide the first supply voltage to the spindle motor circuitry and the VCM circuitry via the first isolation circuit; and
wherein the control circuitry is further operable to:
monitor the first and second host supply lines for an overvoltage event; and
when the overvoltage event is detected:
control the first isolation circuit to disconnect the spindle motor circuitry and the VCM circuitry from the first voltage rail;
control the second isolation circuit to disconnect the second host supply line from the power device; and
control the third isolation circuit to disconnect the first host supply line from the power device.

2. The data storage device as recited in claim 1 , wherein the power device further comprises an Analog to Digital Converter (ADC) channel, and wherein the control circuitry is further operable to monitor the first voltage rail via the ADC channel.

3. The data storage device as recited in claim 1 , wherein the power device further comprises an ADC channel, and wherein the control circuitry is further operable to monitor the first host supply line via the ADC channel.

4. The data storage device as recited in claim 1 , further comprising a charge storage element coupled to a backup circuit, wherein the backup circuit is coupled to the second voltage rail, and wherein the control circuitry is further operable to control the backup circuit to provide a backup voltage to the power device when the first host supply line is disconnected from the power device.

5. The data storage device as recited in claim 4 , wherein the power device further comprises a boost switching regulator operable to charge the charge storage element to the backup voltage.

6. The data storage device as recited in claim 4 , wherein the backup voltage enables the control circuitry to continue to monitor the first host supply line and the first voltage rail after detection of the overvoltage event.

7. The data storage device as recited in claim 4 , further comprising rotating media and one or more heads, wherein the backup voltage enables the control circuitry to initiate a VCM retract procedure to move the one or more heads off the rotating media.

8. The data storage device as recited in claim 4 , further comprising a controller coupled to the power device, wherein the control circuitry is further operable to notify the controller that the overvoltage event has occurred.

9. The data storage device as recited in claim 4 , wherein the control circuitry is further operable to, after determining that the overvoltage event has ended and the first supply voltage is at an operational level:
control the first isolation circuit to connect the first voltage rail to the spindle motor circuitry and the VCM circuitry; and
control the second isolation circuit to connect the second host supply line to the power device.

10. A data storage device comprising:
spindle motor circuitry;
Voice Coil Motor (VCM) circuitry; and
a power device coupled to a host power supply via first and second host supply lines and coupled to the spindle motor circuitry and the VCM circuitry, the power device comprising:
first and second voltage rails;
a first isolation circuit; and
control circuitry;

a second isolation circuit coupled to the second host supply line between the host power supply and the power device; and
a third isolation circuit coupled to the first host supply line between the host power supply and the power device;
wherein the power device is operable to receive a first supply voltage on the first voltage rail via the first host supply line and a second supply voltage on the second voltage rail via the second host supply line and provide the first supply voltage to the spindle motor circuitry and the VCM circuitry via the first isolation circuit;
wherein the control circuitry is further operable to:
monitor the first and second voltage rails for an overvoltage event; and
when the overvoltage event is detected:
control the first isolation circuit to disconnect the spindle motor circuitry and the VCM circuitry from the first voltage rail;
control the second isolation circuit to disconnect the second host supply line from the power device; and
control the third isolation circuit to disconnect the first host supply line from the power device.

11. The data storage device as recited in claim 10 , wherein the power device further comprises first and second ADC channels, and wherein the control circuitry is further operable to monitor the first voltage rail via the first ADC channel and the second voltage rail via the second ADC channel.

12. The data storage device as recited in claim 10 , wherein the power device further comprises an ADC channel, and wherein the control circuitry is further operable to monitor the second host supply line via the ADC channel.

13. The data storage device as recited in claim 10 , further comprising a charge storage element coupled to a backup circuit, wherein the backup circuit is coupled to the second voltage rail, and wherein the control circuitry is further operable to control the backup circuit to provide a backup voltage on the second voltage rail when the second host supply line is disconnected from the power device and the spindle motor circuitry and the VCM circuitry are disconnected from the first voltage rail.

14. The data storage device as recited in claim 13 , wherein the power device further comprises a boost switching regulator operable to charge the charge storage element to the backup voltage.

15. The data storage device as recited in claim 10 , wherein the power device further comprises an ADC channel, and wherein the control circuitry is operable to monitor the first host supply line via the ADC channel.

16. The data storage device as recited in claim 13 , wherein the backup voltage enables the control circuitry to continue to monitor the first and second host supply lines and the first and second voltage rails after detection of the overvoltage event.

17. The data storage device as recited in claim 13 , further comprising rotating media and one or more heads, wherein the backup voltage enables the control circuitry to initiate a VCM retract procedure to move the one or more heads off the rotating media and brake a spindle motor associated with the spindle motor circuitry.

18. The data storage device as recited in claim 10 , further comprising a controller coupled to the power device, wherein the control circuitry is further operable to notify the controller that the overvoltage event has been detected.

19. The data storage device as recited in claim 10 , wherein the control circuitry is further operable to, after determining that the overvoltage event has ended and the first and second supply voltages are at respective operational levels:
control the first

Assignees

• Western Digital Tech Inc

Inventors

• Agness John R
• Laird William K
• Ung Henry S
• Pratama Andre
• Gayler Ronald G

Classifications

• G11B19/20 Primary

  Driving; Starting; Stopping; Control thereof · CPC title

• G11B15/46 Primary

  Controlling, regulating, or indicating speed {(dependent on position of tape in reserve, loop G11B15/56, G11B15/58)} · CPC title

• G11B19/2063

  Spindle motor power-down sequences · CPC title

• G11B19/2081

  emergency power-down · CPC title

• G06F1/26

  Power supply means, e.g. regulation thereof (for memories G11C) · CPC title