Tuning a variable resistance of a resistive sense element

• US 8,289,748 B2
• Filed: 07/06/2009
• Issued: 10/16/2012
• Est. Priority Date: 10/27/2008
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Lee, Brian S., Xi, Haiwen, Ryan, Patrick J., Bowman, Rod
• Primary Examiner(s): NGUYEN, VAN THU T
• Application Number:
  US12/497,929
• Publication Number:
  US 20100103717A1
• Time in Patent Office: 1,198 Days
• Field of Search: 365/148.O, 365/163.X, 365/148, 365/163
• US Class Current: 365/148
• CPC Class Codes: G11C 11/22 using ferroelectric elements
• CPC Class Codes: G11C 13/0004 comprising amorphous/crystalline phase transition cells
• CPC Class Codes: G11C 13/0007 comprising metal oxide memory material, e.g. perovskites
• CPC Class Codes: G11C 13/0069 Writing or programming circuits or methods
• CPC Class Codes: G11C 2013/0073 Write using bi-directional cell biasing
• CPC Class Codes: G11C 2207/2254 Calibration
• CPC Class Codes: G11C 2213/31 Material having complex metal oxide, e.g. perovskite structure
• CPC Class Codes: G11C 29/02 Detection or location of defective auxiliary circuits, e.g. defective refresh counters
• CPC Class Codes: G11C 29/026 in sense amplifiers
• CPC Class Codes: G11C 29/028 with adaption or trimming of parameters
• CPC Class Codes: G11C 29/50008 of impedance
• CPC Class Codes: G11C 7/06 Sense amplifiers; Associated circuits , e.g. timing or triggering circuits

Abstract

Method and apparatus for tuning a variable resistance resistive sense element of an electronic device. In some embodiments, a value indicative of a selected number of consecutive pulses is stored in a memory location and a resistive sense element (RSE) is set to a baseline RSE resistance. A tuning operation is performed by applying the selected number of consecutive pulses to the RSE to tune the baseline RSE resistance to a final adjusted resistance.

Claims

1. A method comprising:

selecting a value in response to a detected impedance mismatch between a port and a circuit, the value indicative of a selected number of consecutive pulses corresponding to a correction resistance;

setting a resistive sense element (RSE) to a baseline RSE resistance; and

performing a tuning operation by applying the selected number of consecutive pulses to the RSE to tune the baseline RSE resistance to the correction that compensates for the impedance mismatch.

2. The method of claim 1, wherein a count is incremented for every consecutive pulse.

3. The method of claim 2, wherein an error flag is issued if the count reaches a predetermined number.

4. The method of claim 2, wherein the count resets upon failing to be verified within a predetermined resistance range.

5. The method of claim 1, wherein the final adjusted resistance corresponds with the formation of an electrically conductive filament through the RSE.

6. The method of claim 1, wherein the final adjusted resistance is verified between a predetermined maximum value and a predetermined minimum value.

7. The method of claim 1, wherein the RSE is tested multiple times for compliance with a predetermined resistance minimum value and a predetermined resistance maximum value.

8. The method of claim 1, wherein the selected number of consecutive pulses is applied multiple times to the RSE in order to reach the final adjusted resistance.

9. An apparatus comprising control circuitry configured to detect an impedance mismatch between a circuit and a port, the control circuitry capable of selecting a value indicative of a selected number of consecutive pulses corresponding to a correction resistance, the control circuitry capable of setting a resistive sense element (RSE) to a baseline RSE resistance, and performing a tuning operation by applying the selected number of consecutive pulses to the RSE to tune the baseline RSE resistance to the correction resistance that compensates for the impedance mismatch.

10. The apparatus of claim 9, wherein the baseline RSE resistance a low resistance state.

11. The apparatus of claim 9, wherein the baseline RSE resistance a high resistance state.

12. The apparatus of claim 9, wherein the selected number of pulses is repeatedly retrieved from the memory location during the performance step.

13. The apparatus of claim 9, wherein the pulses induce non-linear incremental changes in said resistance.

14. The apparatus of claim 9, wherein the RSE is used for electro-Static Discharge protection of a port of a circuit.

15. The apparatus of claim 9, wherein the RSE is tested to set a final adjusted resistance.

16. The apparatus of claim 9, wherein the RSE comprises a perovskite complex oxide disposed between a top electrode and a bottom electrode.

17. The apparatus of claim 16, wherein the top electrode and bottom electrode are formed of dissimilar materials.

18. A method comprising:

connecting a circuit to first and second ports respectively with first and second resistive sense elements (RSE), each port having a different impedance;

selecting different first and second values for the first and second RSE in response to a detected impedance mismatch between the first and second ports and the circuit, the first and second values respectively indicative of a selected number of consecutive pulses corresponding to first and second correction resistances;

setting the first and second RSE to a baseline RSE resistance; and

performing a tuning operation by applying the respective selected number of consecutive pulses to the first and second RSE to tune the baseline RSE resistance to the first and second correction resistances that matches the first and second impedances of the respective first and second ports.

19. The method of claim 18, wherein the tuning operation applies a predetermined polarity of positive and negative polarity pulses to modify the electrically conductive filament.

20. The method of claim 18, wherein the final adjusted resistance matches an internal impedance of the circuit.