Variable Power Write Driver Circuit

• US 20080290908A1
• Filed: 05/23/2007
• Published: 11/27/2008
• Est. Priority Date: 05/23/2007
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Tretter, Larry L.
• Granted Patent: US 7,688,536 B2
• Time in Patent Office: Days
• US Class Current: 327/108
• CPC Class Codes: G11B 5/022 H-Bridge head driver circuit, the "H" configuration allowing to inverse the current direction in the head
• CPC Class Codes: G11B 5/09 Digital recording

Abstract

A storage system (e.g., a magnetic disk system or a magnetic tape system) employing a write head, a write controller and a write driver circuit. In operation, the write head records data on a magnetic media (e.g., a magnetic tape or a magnetic disk) based on a flow of a write current through the write head, and the write driver circuit includes a variable power supply network and a variable power return network driving the write current through the write head based on a selection by the write controller of an operating power mode among a plurality of selectable power modes of the variable power supply network and the variable power return network. Each power mode of the variable power supply network and the variable power return network drives the write current with a different magnitude from the variable power supply network through the write head to the variable power return network.

Claims

1. A method of operating a storage drive, the method comprising

a write controller selecting an operating power mode among a plurality of selectable power modes of a variable power supply network and a variable power return network,

wherein each power mode of the variable power supply network and the variable power return network drives a write current with a different magnitude from the variable power supply network through a write head to the variable power return network;

and

the write head recording data on a magnetic media based on the flow of the write current through the write head.

2. The method of claim 1, wherein the write controller selecting the operating power mode among the plurality of selectable power modes of the variable power supply network and the variable power return network includes:

the write controller communicating at least one control supply signal to a logic power supply manager, the at least one control supply signal being representative of the selected operating power mode.

3. The method of claim 2, wherein the write controller selecting the operating power mode among the plurality of selectable power modes of the variable power supply network and the variable power return network further includes:

the logic power supply manager communicating at least one supply switching signal to the variable power supply network to switch the variable power supply network to a power mode configuration corresponding to the at least one control supply signal.

4. The method of claim 1, wherein the write controller selecting the operating power mode among the plurality of selectable power modes of the variable power supply network and the variable power return network includes:

the write controller communicating at least one control return signal to a logic power return manager, the at least one control return signal being representative of the selected operating power mode.

5. The method of claim 4, wherein the write controller selecting the operating power mode among the plurality of selectable power modes of the variable power supply network and the variable power return network further includes:

the logic power return manager communicating at least one return switching signal to the variable power return network to switch the variable power return network to a power mode configuration corresponding to the at least one control return signal.

6. A storage drive, comprising:

a write head recording data on a magnetic media based on a flow of a write current through the write head; and

a write driver circuit including a variable power supply network and a variable power return network driving the write current through the write head based on a selection of an operating power mode among a plurality of selectable power modes of the variable power supply network and the variable power return network,

wherein each power mode of the variable power supply network and the variable power return network drives the write current with a different magnitude from the variable power supply network through the write head to the variable power return network.

7. The storage device of claim 6, wherein the write driver circuit further includes:

a logic power supply manager receiving at least one control supply signal representative of the selected operating power mode.

8. The storage device of claim 7, wherein the logical power supply manager communicates at least one supply switching signal to the variable power supply network to switch the variable power supply network to a power mode configuration corresponding to the at least one control supply signal.

9. The storage device of claim 6, wherein the variable power supply network includes:

a plurality of write drivers connected in parallel between a positive supply node and a negative supply node.

10. The storage device of claim 9, wherein the write driver circuit further includes:

a logic power supply manager receiving at least one control supply signal representative of the selected operating power mode and communicating a supply switching signal to each electronic switch to switch the variable power supply network to a power mode configuration corresponding to the at least one control supply signal.

11. The storage device of claim 6, wherein the write driver circuit further includes;

a logic power return manager receiving at least one control return signal representative of the selected operating power mode.

12. The storage device of claim 11, wherein the logical power return manager communicates at least one return switching signal to the variable power return network to switch the variable power return network to a power mode configuration corresponding to the at least one control return signal.

13. The storage device of claim 6, wherein the variable power return network includes:

a plurality of write drivers connected in parallel between a positive return node and a negative return node.

14. The storage device of claim 13, wherein the write driver circuit further includes:

a logic power return manager receiving at least one control return signal representative of the selected operating power mode and communicating a return switching signal to each electronic switch to switch the variable power return network to a power mode configuration corresponding to the at least one control return signal.

15. A storage system, comprising:

a write head recording data on a magnetic media based on a flow of a write current through the write head;

a write controller; and

a write driver circuit including a variable power supply network and a variable power return network driving the write current through the write head based on a selection by the write controller of an operating power mode among a plurality of selectable power modes of the variable power supply network and the variable power return network,

wherein each power mode of the variable power supply network and the variable power return network drives the write current with a different magnitude from the variable power supply network through the write head to the variable power return network.

16. The storage system of claim 15, wherein the write driver circuit further includes:

a logic power supply manager receiving at least one control supply signal representative of the selected operating power mode from the write controller.

17. The storage system of claim 16, wherein the logical power supply manager communicates at least one supply switching signal to the variable power supply network to switch the variable power supply network to a power mode configuration corresponding to the at least one control supply signal.

18. The storage system of claim 15, wherein the variable power supply network includes:

a plurality of write drivers connected in parallel between a positive supply node and a negative supply node.

19. The storage system of claim 18, wherein the write driver circuit further includes:

a logic power supply manager receiving at least one control supply signal representative of the selected operating power mode from the write controller and communicating a supply switching signal to each electronic switch to switch the variable power supply network to a power mode configuration corresponding to the at least one control supply signal.

20. The storage system of claim 15, wherein the write driver circuit further includes;

a logic power return manager receiving at least one control return signal representative of the selected operating power mode from the write controller.

21. The storage system of claim 20, wherein the logical power return manager communicates at least one return switching signal to the variable power return network to switch the variable power return network to a power mode configuration corresponding to the at least one control return signal.

22. The storage system of claim 15, wherein the variable power return network includes:

a plurality of write drivers connected in parallel between a positive return node and a negative return node.

23. The storage system of claim 22, wherein the write driver circuit further includes:

a logic power return manager receiving at least one control return signal representative of the selected operating power mode from the write controller and communicating a return switching signal to each electronic switch to switch the variable power return network to a power mode configuration corresponding to the at least one control return signal.