Holdup capacitor energy harvesting

• US 9,443,601 B2
• Filed: 09/08/2014
• Issued: 09/13/2016
• Est. Priority Date: 09/08/2014
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Inventors: Lucas, Gregg S., Ellis, Robert W.
• Primary Examiner(s): LE, TOAN K
• Application Number:
  US14/479,559
• Publication Number:
  US 20160071609A1
• Time in Patent Office: 736 Days
• Field of Search: 365/185.18, 365/227
• US Class Current: 1/1
• CPC Class Codes: G06F 1/30 Means for acting in the event of power-supply failure or interruption, e.g. power-supply fluctuations for resetting only G06F1/24
• CPC Class Codes: G06F 11/14 Error detection or correction of the data by redundancy in operation G06F11/16 takes precedence
• CPC Class Codes: G06F 11/1402 Saving, restoring, recovering or retrying
• CPC Class Codes: G11C 16/225 Preventing erasure, programming or reading when power supply voltages are outside the required ranges
• CPC Class Codes: G11C 16/30 Power supply circuits
• CPC Class Codes: G11C 5/148 Details of power up or power down circuits, standby circuits or recovery circuits

Abstract

The various embodiments described herein include circuits, methods and/or devices used to protect data in a storage device. In one aspect, a method includes performing a power fail operation on a first section of the storage device. The power fail operation includes supplying power, via an energy storage device, to the first section of the storage device, where the energy storage device is distinct from a power source used during normal operation of the storage device, and where supplying power via the energy storage device includes switching the output of the energy storage device from an output of a boost regulator to an input of the boost regulator. The power fail operation also includes performing data hardening on the first section of the storage device.

Claims

1. A circuit to protect data in a storage device, the circuit comprising:

an energy storage device;

a boost regulator for boosting an input voltage;

a load switch for selectively coupling a power source to the input of the boost regulator, wherein the load switch is configured to de-couple the power source from the input of the boost regulator in response to receiving a power fail signal;

a selector for selectively coupling the energy storage device to either an input or an output of the boost regulator;

wherein the selector is configured to couple the energy storage device to the output of the boost regulator during normal operation of the storage device; and

wherein the selector is further configured to couple the energy storage device to the input of the boost regulator in response to receiving a first signal; and

a plurality of regulators coupled to the output of the boost regulator for supplying power to a first portion of the storage device.

2. The circuit of claim 1, wherein the first signal is the power fail signal.

3. The circuit of claim 1, wherein the first signal is a switchover signal, the switchover signal generated in response to a voltage output of the energy storage device falling below a predetermined threshold.

4. The circuit of claim 3, wherein the predetermined threshold corresponds to a minimum input voltage required by at least one regulator in the plurality of regulators to supply useable power to the first portion of the storage device.

5. The circuit of claim 1, further comprising a comparator having an output comprising the first signal.

6. The circuit of claim 1, wherein the energy storage device comprises one or more capacitors.

7. The circuit of claim 1, wherein the first signal corresponds to a power fail operation.

8. The circuit of claim 1, wherein, during normal operation, the energy storage device is used to buffer power spikes.

9. A method of protecting data in a storage device comprising volatile memory and non-volatile memory, the method comprising:

performing a power fail operation on a first section of the storage device, the power fail operation including;

supplying power, via an energy storage device, to the first section of the storage device;

wherein the energy storage device is distinct from a power source used during normal operation of the storage device; and

wherein supplying power via the energy storage device includes switching the output of the energy storage device from an output of a boost regulator to an input of the boost regulator; and

performing data hardening on the first section of the storage device.

10. The method of claim 9, wherein switching the output of the energy storage device from the output of the boost regulator to the input of the boost regulator comprises switching the output of the energy storage device in response to receiving a first signal.

11. The method of claim 10, wherein the first signal is a power fail signal generated by a first controller on the storage device.

12. The method of claim 10, wherein the first signal is a switchover signal, the switchover signal generated in response to a voltage output of the energy storage device falling below a predetermined threshold.

13. The method of claim 12, wherein the predetermined threshold corresponds to a minimum input voltage required by a first regulator to supply useable power to the first portion of the storage device.

14. The method of claim 9, wherein the energy storage device comprises one or more capacitors.

15. The method of claim 9, further comprising utilizing the energy storage device to buffer power spikes received from the power source used during normal operation of the storage device.

16. The method of claim 10, wherein the power fail operation is performed on the first section of the storage device in response to a second signal.

17. A non-transitory computer readable storage medium, storing one or more programs for execution by one or more processors of a storage device, the one or more programs including instructions for:

performing a power fail operation on a first section of the storage device, the power fail operation including;

supplying power, via an energy storage device, to the first section of the storage device;

wherein the energy storage device is distinct from a power source used during normal operation of the storage device; and

wherein supplying power via the energy storage device includes switching the output of the energy storage device from an output of a boost regulator to an input of the boost regulator; and

performing data hardening on the first section of the storage device.

18. The computer readable storage medium of claim 17, wherein switching the output of the energy storage device from the output of the boost regulator to the input of the boost regulator comprises switching the output of the energy storage device in response to receiving a first signal.

19. The computer readable storage medium of claim 18, wherein the first signal is a power fail signal generated by a first controller on the storage device.

20. The computer readable storage medium of claim 18, wherein the first signal is a switchover signal, the switchover signal generated in response to a voltage output of the energy storage device falling below a predetermined threshold.

21. The computer readable storage medium of claim 20, wherein the predetermined threshold corresponds to a minimum input voltage required by a first regulator to supply useable power to the first portion of the storage device.

22. The computer readable storage medium of claim 17, wherein the energy storage device comprises one or more capacitors.

23. The computer readable storage medium of claim 17, further comprising utilizing the energy storage device to buffer power spikes received from the power source used during normal operation of the storage device.

24. The computer readable storage medium of claim 18, wherein the power fail operation is performed on the first section of the storage device in response to a second signal.