Data storage device employing cascaded voltage regulators during power failure

• US 8,767,354 B1
• Filed: 12/08/2011
• Issued: 07/01/2014
• Est. Priority Date: 12/08/2011
• Status: Active Grant

• Current Assignee: Sandisk Technologies Incorporated (Western Digital Corporation)
• Original Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Inventors: Ferris, Timothy A., Agness, John R., Ryan, Robert P.
• Primary Examiner(s): ALUNKAL, THOMAS D
• Application Number:
  US13/314,475
• Time in Patent Office: 936 Days
• Field of Search: 360/73.01, 360/75, 360/272, 360/55, 365/226, 365/227, 365/228, 363/10
• US Class Current: 360/272
• CPC Class Codes: G11B 5/012 Recording on, or reproducing or erasing from, magnetic disks G11B17/00, G11B19/00 take precedence
• CPC Class Codes: G11B 5/40 Protective measures on heads, e.g. against excessive temperature G11B5/31 takes precedence; protection against wear G11B5/255 ; protective structure of the head: see under structures, e.g. G11B5/3106
• CPC Class Codes: G11B 5/54 with provision for moving the head into or out of its operative position or across tracks

Abstract

A data storage device is disclosed comprising a non-volatile memory and control circuitry comprising an interface operable to receive a supply voltage, and a capacitor. An operating voltage regulator converts the supply voltage into an operating voltage used to operate the non-volatile memory. The supply voltage is used to charge the capacitor to a capacitor voltage higher than the supply voltage, and during a power failure, a backup voltage regulator converts the capacitor voltage into a backup voltage substantially equal to the supply voltage. The operating voltage regulator converts the backup voltage into the operating voltage used to operate the non-volatile memory.

Claims

1. A data storage device comprising:

a non-volatile memory; and

control circuitry comprising an interface operable to receive a supply voltage, and

a capacitor, wherein the control circuitry is operable to;

use an operating voltage regulator to convert the supply voltage into an operating voltage used to operate the non-volatile memory;

use the supply voltage to charge the capacitor to a capacitor voltage higher than the supply voltage; and

during a power failure;

use a backup voltage regulator to convert the capacitor voltage into a backup voltage substantially equal to the supply voltage; and

use the operating voltage regulator to convert the backup voltage into the operating voltage used to operate the non-volatile memory.

2. The data storage device as recited in claim 1, wherein the control circuitry is operable to:

boost the supply voltage to a boosted voltage higher than the supply voltage; and

charge the capacitor with the boosted voltage.

3. The data storage device as recited in claim 2, further comprising a microactuator operable to actuate a head radially over a disk, wherein the control circuitry is operable to control the microactuator using the boosted voltage.

4. The data storage device as recited in claim 1, further comprising a microactuator wherein during the power failure the control circuitry is operable to:

boost the backup voltage to a boosted voltage higher than the backup voltage; and

control the microactuator using the boosted voltage.

5. The data storage device as recited in claim 1, wherein the operating voltage is lower than the backup voltage.

6. The data storage device as recited in claim 1, wherein the operating voltage is higher than the backup voltage.

7. The data storage device as recited in claim 6, further comprising a voice coil motor (VCM) operable to actuate a head radially over a disk, wherein the control circuitry is operable to control the VCM using the operating voltage.

8. The data storage device as recited in claim 1, wherein the interface receives the supply voltage from a host.

9. The data storage device as recited in claim 1, wherein the non-volatile memory comprises a disk.

10. The data storage device as recited in claim 1, wherein the non-volatile memory comprises a semiconductor memory.

11. A method of operating a data storage device comprising a non-volatile memory, an interface operable to receive a supply voltage, and a capacitor, the method comprising:

using an operating voltage regulator to convert the supply voltage into an operating voltage used to operate the non-volatile memory;

using the supply voltage to charge the capacitor to a capacitor voltage higher than the supply voltage; and

during a power failure;

using a backup voltage regulator to convert the capacitor voltage into a backup voltage substantially equal to the supply voltage; and

using the operating voltage regulator to convert the backup voltage into the operating voltage used to operate the non-volatile memory.

12. The method as recited in claim 11, further comprising:

boosting the supply voltage to a boosted voltage higher than the supply voltage; and

charging the capacitor with the boosted voltage.

13. The method as recited in claim 12, wherein the data storage device further comprises a microactuator operable to actuate a head radially over a disk, the method further comprising controlling the microactuator using the boosted voltage.

14. The method as recited in claim 11, wherein the data storage device further comprises a microactuator and during the power failure the method further comprising:

boosting the backup voltage to a boosted voltage higher than the backup voltage; and

controlling the microactuator using the boosted voltage.

15. The method as recited in claim 11, wherein the operating voltage is lower than the backup voltage.

16. The method as recited in claim 11, wherein the operating voltage is higher than the backup voltage.

17. The method as recited in claim 16, wherein the data storage device further comprises a voice coil motor (VCM) operable to actuate a head radially over a disk, the method further comprising controlling the VCM using the operating voltage.

18. The method as recited in claim 11, wherein the interface receives the supply voltage from a host.

19. The method as recited in claim 11, wherein the non-volatile memory comprises a disk.

20. The method as recited in claim 11, wherein the non-volatile memory comprises a semiconductor memory.