Systems, methods and devices for backup power control in data storage devices

• US 8,065,562 B2
• Filed: 12/07/2009
• Issued: 11/22/2011
• Est. Priority Date: 06/26/2009
• Status: Expired due to Fees

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Wilson, Dean Clark, Johnston, Darren Edward
• Primary Examiner(s): LOHN, JOSHUA A
• Application Number:
  US12/632,539
• Publication Number:
  US 20100332896A1
• Time in Patent Office: 715 Days
• Field of Search: 714/22, 714/25, 714/721, 713/340, 320/136, 320/167, 365/226, 365/228
• US Class Current: 714/22
• 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

Abstract

Power-backup capabilities are provided by implementing a variety of different methods, systems and devices. According to one such implementation, a capacitive storage circuit is operated at a threshold voltage that is set to provide sufficient power to operate backup functions of a data storage device, and that is further selectively adjusted during a test period to maintain such sufficient power while also providing power to carry out test functions. In other implementations, the threshold voltage is set in response to operating characteristics of one or more of a data storage device to which backup power is to be provided and the capacitive storage circuit itself. The threshold voltage is reduced or otherwise maintained at a low level that is yet sufficient to supply appropriate power (e.g., thus maintaining the capacitive circuit at a voltage level that is about as low as possible, which can enhance operational characteristics of the capacitive circuit).

Claims

1. A backup power circuit for powering a data storage circuit in response to a power interruption, the circuit comprising:

a capacitive circuit configured to store and use capacitive energy for powering backup functions of the data storage circuit in response to a power interruption, and for powering a test load to test the capacitive circuit;

a test circuit configured to detect operational characteristics of the capacitive circuit in response to the capacitive circuit powering the test load; and

an adaptive control circuit configured to, in response to the detected operational characteristics

set the charge in the capacitive circuit to a backup threshold voltage for powering the backup functions of the data storage circuit, and

set the charge in the capacitive circuit to a test threshold voltage for powering the test load during a test period, the test threshold voltage being higher than a backup threshold voltage needed by the capacitive circuit in order to power the backup functions during the test period.

2. The circuit of claim 1, wherein the adaptive control circuit is configured to set the backup threshold voltage in response to the detected operational characteristics.

3. The circuit of claim 1, wherein the adaptive control circuit is configured to set the test threshold voltage, relative to the backup threshold voltage, in response to the detected operational characteristics.

4. The circuit of claim 1, wherein the adaptive control circuit is configured to set the backup threshold voltage in response to the detected operational characteristics, and to set the test threshold voltage based upon the backup threshold voltage and the detected operational characteristics.

5. The circuit of claim 1, wherein

the test circuit is configured to detect operational characteristics of the capacitive circuit by detecting the ability of the capacitive circuit to store and provide energy to power the test load, and

the adaptive control circuit is configured to set the test threshold voltage at a voltage level sufficient to charge the capacitive circuit to provide sufficient energy to power both the backup functions of the data storage circuit and the test load, in response to the detected ability of the capacitive circuit to store and provide energy.

6. The circuit of claim 1, wherein

the test circuit is configured to detect operational characteristics of the capacitive circuit by detecting the ability of the capacitive circuit to store energy, and

the adaptive control circuit is configured to set the test threshold voltage at a voltage level sufficient to charge the capacitive circuit for powering both the backup functions of the data storage circuit and the test load, in response to the detected ability of the capacitive circuit to store energy.

7. The circuit of claim 1, wherein

the test circuit is configured to detect operational characteristics of the capacitive circuit by detecting the ability of the capacitive circuit to store and provide energy to power the test load, and

the adaptive control circuit is configured to set the backup threshold voltage at a voltage level sufficient to charge the capacitive circuit for powering the backup functions of the data storage circuit, in response to the detected ability of the capacitive circuit to store and provide energy.

8. The circuit of claim 1, wherein the test circuit is configured to

operate the capacitive circuit to power the test load under multiple test voltage conditions during an initialization test cycle,

detect operational characteristics of the capacitive circuit by detecting the ability of the capacitive circuit to store and provide energy to power the test load under each of the multiple test voltage conditions, and

in response to the detected ability of the capacitive circuit to store and provide energy, set the backup threshold voltage at a reduced backup threshold voltage level that is sufficient to charge the capacitive circuit for providing energy to power the backup functions of the data storage circuit.

9. The circuit of claim 1, wherein the test circuit is configured to

successively operate the capacitive circuit to power the test load at a predetermined interval to detect the operational characteristics of the capacitive circuit, and

in response to detecting a deterioration in operation of the capacitive circuit via the successive operation of the capacitive circuit, set the backup threshold voltage at an increased voltage level to store sufficient power for powering backup functions of the data storage circuit.

10. The circuit of claim 1, wherein the test circuit is configured to set the test threshold voltage to a new value in response to temperature-based parametric changes of the capacitive circuit.

11. The circuit of claim 1, wherein the adaptive control circuit is configured to dynamically set the backup threshold voltage in response to real-time operational characteristics of the data storage circuit to increase the stored energy in the capacitive circuit as backup power requirements of the data storage circuit increase, and to decrease the stored energy in the capacitive circuit as backup power requirements of the data storage circuit decrease.

12. The circuit of claim 1, wherein the adaptive control circuit is configured to dynamically set the backup threshold voltage according to a predefined state of the data storage circuit.

13. The circuit of claim 1, wherein the adaptive control circuit is configured to control the operation of the data storage circuit to limit the amount of backup power required for powering the backup functions of the data storage circuit, based upon capacitive energy stored in the capacitive circuit.

14. The circuit of claim 1, wherein the adaptive control circuit operates the capacitive circuit in a test cycle for powering the test load to test the capacitive circuit during a low-power state of the data storage circuit.

15. The circuit of claim 1, further including a discharge storage circuit coupled to the test load to store capacitive energy drained from the capacitive circuit and to provide the stored capacitive energy for use in powering the data storage circuit in response to a power interruption.

16. The circuit of claim 1,

further including a second capacitive circuit configured to store and use capacitive energy for powering backup functions of the data storage circuit in response to a power interruption, and for powering a test load to test the capacitive circuit,

wherein the test circuit is configured to detect operational characteristics of the capacitive circuit in response to the second capacitive circuit powering the test load,

wherein the adaptive control circuit is configured to, in response to the detected operational characteristics of the capacitive circuits

set the charge in the respective capacitive circuits to backup threshold voltages for powering the backup functions of the data storage circuit, and

set the charge in the respective capacitive circuits to test threshold voltages during a test period in which one of the capacitive circuits is used to power the test load, the test threshold voltages being higher than a backup threshold voltage needed by the respective capacitive circuits to cooperatively power the backup functions during the test period.

17. A backup power control circuit for charging a capacitive circuit that stores and uses capacitive energy for powering backup functions of a data storage circuit and for powering a test load during a test condition, the circuit comprising:

a voltage supply circuit coupled to the capacitive circuit for charging the capacitive circuit from a backup voltage level to a higher boost voltage level; and

a controller configured to control the voltage supply circuit to boost the charge in the capacitive circuit from the backup voltage level to the boost voltage level for powering the test load during the test condition, and to control the capacitive circuit to return to the backup voltage level under non-test conditions, and to set the boost and backup voltage levels based upon the operation of the capacitive circuit during the test condition.

18. The circuit of claim 17, wherein the controller is configured to control the voltage supply circuit to

charge the capacitive circuit to the backup voltage level during non-test conditions, and

after boosting the charge in the capacitive circuit to the boost voltage level for a test condition, upon completion of the test condition, control the voltage supply circuit to permit the capacitive circuit to return to the backup voltage level and to maintain the capacitive circuit at the backup voltage level.

19. The circuit of claim 17, wherein the controller sets the backup voltage level to a threshold level that sufficiently charges the capacitive circuit to at least a minimum threshold charge required to operate the data storage circuit to carry out the backup functions during non-test conditions, and that insufficiently charges the capacitive circuit to operate the data storage circuit to carry out the backup functions while the capacitive circuit is powering the test load under the test condition.

20. A solid-state data storage device comprising:

a primary solid-state memory circuit configured and arranged to maintain data integrity in the absence of operating power;

a caching memory circuit mapped to the primary memory circuit, configured and arranged to provide access to a set of data representing a cached portion of memory that is mapped to the primary memory circuit;

a power supply configured to supply operating power to the caching memory circuit;

a backup power circuit including a capacitive circuit configured to store capacitive energy and coupled to use the stored capacitive energy to provide power to the caching memory circuit and the primary solid-state memory circuit for backing up data in the caching memory circuit;

a test circuit configured to detect operational characteristics of the capacitive circuit under a test condition; and

a control circuit configured to charge the capacitive circuit to a threshold voltage that is set in response to the detected operational characteristics, and to control the capacitive circuit to provide power to the caching memory circuit and the primary solid-state memory circuit in response to an interruption in power from the power supply.