Data storage device with adaptive control of current balancer to reduce power consumption

1 . A data storage device comprising:

a disk;

a head configured to read data from and write data to the disk; and

a current balancer configured to:

receive a first current from a first voltage supply having a load limit,

receive a second current from a second voltage supply,

sample, at a plurality of times, the first current drawn from the first voltage supply,

based on the sampled first current, adjust a draw of the second current from the second voltage supply to satisfy a part of a total load on the first voltage supply that exceeds the load limit while the first current is regulated to be at a target level approximately equal to the load limit, and

generate a current balancer threshold voltage parameter and a current balancer gain parameter for regulating the first current at the target level based on the sampled first current.

2 . The data storage device of claim 1 , wherein the current balancer comprises:

an analog-to-digital converter (ADC) configured to sample the first current sensed by a current sensor; and

a system-on-a-chip (SoC) configured to receive the sampled first current from the ADC, and control the current balancer based on the sampled first current at each of the plurality of times.

3 . The data storage device of claim 2 , wherein the SoC is further configured to generate the current balancer threshold voltage parameter and the current balancer gain parameter for controlling the current balancer based on the sampled first current received from the ADC.

4 . The data storage device of claim 3 , wherein the SoC is further configured to generate the current balancer threshold voltage parameter and the current balancer gain parameter by referring to a data structure.

5 . The data storage device of claim 3 , wherein the current balancer further comprises registers that are coupled to the SoC and that are configured to receive and store the current balancer threshold voltage parameter and the current balancer gain parameter from the SoC.

6 . The data storage device of claim 3 , wherein the ADC is further configured to periodically update the sampled first current that is provided to the SoC, and wherein the SoC is further configured to periodically update the current balancer threshold voltage parameter and the current balancer gain parameter.

7 . The data storage device of claim 3 , wherein the ADC is further configured to update the sampled first current provided to the SoC at each servo identification (ID) or at an interval of predetermined number of a plurality of servo IDs.

8 . The data storage device of claim 3 , wherein:

DSR I pk is the second current drawn by the current balancer from the second voltage supply;

I H5V is the sampled first current as converted to a voltage;

I Threshold is the current balancer threshold voltage parameter;

Gain is the current balancer gain parameter;

minCurrentLimit pk is a minimum current amount required for turn on of the current balancer; and

the second current is represented by:

DSR

⁢

I

p

⁢

k

=

(

(

I

H

⁢

5

⁢

V

-

I

Threshold

)

×

Gain

)

+

minCurrentLimit

p

⁢

k

.

9 . The data storage device of claim 1 , wherein the first voltage supply is configured to supply a low voltage of approximately 5V, and the second voltage supply is configured to supply a high voltage of approximately 12V.

10 . The data storage device of claim 2 , further comprising a circuit protection device that is configured to be coupled to the first and second voltage supplies, the circuit protection device comprising the current sensor.

11 . The data storage device of claim 10 , wherein the circuit protection device is a dual electrical fuse (efuse).

12 . A method for reducing power consumption by a current balancer of a data storage device, the current balancer configured to receive a first current from a first voltage supply having a load limit and a second current from a second voltage supply, the method comprising:

sampling, at a plurality of times, the first current drawn from the first voltage supply;

adjusting, based on the sampled first current, a draw of the second current from the second voltage supply to satisfy a part of a total load on the first voltage supply that exceeds the load limit while regulating the first current to be at a target level approximately equal to the load limit; and

generating a current balancer threshold voltage parameter and a current balancer gain parameter for maintaining the first current at the target level based on the sampled first current.

13 . The method of claim 12 , wherein sampling the first current is performed by an analog-to-digital converter (ADC), the method further comprising:

providing the sampled first current from the ADC to a system-on-a-chip (SoC).

14 . The method of claim 13 , wherein generating the current balancer threshold voltage parameter and the current balancer gain parameter is performed by the SoC based on the sampled first current at each of the plurality of times.

15 . The method of claim 14 , further comprising:

periodically updating the sampled first current that is provided by the ADC to the SoC; and

periodically updating the current balancer threshold voltage parameter and the current balancer gain parameter that are generated by the SoC.

16 . The method of claim 15 , further comprising:

updating the sampled first current at each servo identification (ID) or at an interval of predetermined number of a plurality of servo IDs.

17 . The method of claim 15 , wherein:

DSR I pk is the second current drawn from the second voltage supply;

I H5V is the sampled first current as converted to a voltage;

I Threshold is the current balancer threshold voltage parameter;

Gain is the current balancer gain parameter;

minCurrentLimit pk is a minimum current amount required for turn on of the current balancer; and

the second current is represented by:

DSR

⁢

I

p

⁢

k

=

(

(

I

H

⁢

5

⁢

V

-

I

Threshold

)

×

Gain

)

+

minCurrentLimit

p

⁢

k

.

18 . The method of claim 12 , further comprising:

sensing the first current drawn from the first voltage supply with a current sensor of a circuit protection device.

19 . One or more processing devices for reducing power consumption in a data storage device, the one or more processing devices comprising, individually or in combination:

a current balancer;

means for receiving a first current from a first voltage supply having a load limit;

means for receiving a second current from a second voltage supply;

means for sampling the first current drawn from the first voltage supply;

means for adjusting a draw of the second current from the second voltage supply to satisfy a part of a total first voltage supply load that exceeds the load limit while regulating the first current to be at a target level approximately equal to the load limit; and

means for generating a current balancer threshold voltage parameter and a current balancer gain parameter for maintaining the first current at the target level.

20 . The one or more processing devices of claim 19 , wherein the current balancer comprises:

an analog-to-digital converter (ADC) configured to sample the first current sensed by a current sensor; and

a system-on-a-chip (SoC) configured to receive the sampled first current from the ADC, and control the current balancer based on the sampled first current at a plurality of times.