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Magnetoresistive trimming of GMR circuits

Imported: 23 Feb '17 | Published: 22 Oct '02

Richard Spitzer, E. James Torok

USPTO - Utility Patents

Abstract

Methods and apparatus are described relating to an electronic device which includes at least one configurable resistive element. Each such configurable resistive element includes at least one multi-layer thin film element exhibiting giant magnetoresistance. The resistance value of each configurable resistive element is configurable over a resistance value range by application of at least one magnetic field which manipulates at least one magnetization vector associated with the thin film element. One embodiment is an adjustable output gate. Another embodiment is a differential amplifier in which the gain of each channel is adjustable.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified diagram of a multi-layer thin film element exhibiting giant magnetoresistance (GMR);

FIG. 2 is a graph illustrating the relationship between the resistance of a GMR film and an applied magnetic field;

FIG. 3 shows perspective and cross-sectional views of a memory array for use with specific embodiments of the present invention;

FIG. 4 illustrates the effect of current in a word line of a memory array;

FIG. 5 is a simplified circuit diagram of a transpinnor for use with specific embodiments of the present invention;

FIGS. 6

a and

6

b are simplified representations of a differential transpinnor for use with specific embodiments of the present invention;

FIG. 7 is a simplified schematic diagram of a memory array designed according to a specific embodiment of the present invention;

FIGS. 8

a-

8

d illustrate four different embodiments in which a transpinnor is used to balance a sense-digit/reference line pair;

FIG. 9 is a simplified representation of a differential transpinnor in integrated circuit form;

FIG. 10 is a simplified representation of a hybrid transpinnor; and

FIG. 11 is a simplified representation of a differential transpinnor having two layers of input lines.

Claims

1. An electronic device comprising at least one configurable resistive element having a resistance value associated therewith, each configurable resistive element comprising at least one multi-layer thin film element exhibiting giant magnetoresistance, the resistance value of each configurable resistive element being configurable over a resistance value range by application of at least one magnetic field which manipulates at least one magnetization vector associated with the at least one thin film element.

2. The electronic device of claim 1 wherein each multi-layer thin film element of each configurable resistive element comprises at least one high coercivity layer and at least one low coercivity layer, the resistance value associated with each multi-layer thin film element being configurable by at least partially switching a first magnetization vector associated with the at least one high coercivity layer.

3. The electronic device of claim 1 wherein each configurable resistive element comprises a network of thin-film elements in a bridge configuration, at least one thin-film element exhibiting giant magnetoresistance, and at least one conductor inductively coupled to the at least one thin-film element for applying the at least one magnetic field thereto.

4. The electronic device of claim 3 wherein the network of thin-film elements is configured to operate as a logic gate having an amplification factor associated therewith, and wherein application of the at least one magnetic field results in alteration of the amplification factor.

5. The electronic device of claim 4 wherein each multi-layer thin film element of each configurable resistive element comprises at least one high coercivity layer and at least one low coercivity layer, the resistance value associated with each multi-layer thin film element being configurable by at least partially switching a first magnetization vector associated with the at least one high coercivity layer.

6. The electronic device of claim 4 wherein the electronic device comprises a memory comprising a plurality of memory cells and a plurality of access lines for facilitating access to the memory cells, selected access lines having an output of at least one of the configurable resistive elements directly connected thereto.

7. The electronic device of claim 3 wherein the network of thin-film elements is configured to operate as a differential amplifier having an amplification factor associated with each of two inputs, and wherein application of the at least one magnetic field results in alteration of the amplification factor associated with at least one of the two inputs.

8. The electronic device of claim 7 wherein each multi-layer thin film element of each configurable resistive element comprises at least one high coercivity layer and at least one low coercivity layer, the resistance value associated with each multi-layer thin film element being configurable by at least partially switching a first magnetization vector associated with the at least one high coercivity layer.

9. The electronic device of claim 7 wherein the electronic device comprises a memory comprising a plurality of memory cells and a plurality of sense and reference lines, selected sense and reference lines having the at least one conductor of at least one of the configurable resistive elements directly connected thereto.

10. The electronic device of claim 3 further comprising at least one component having a two-channel output corresponding to first and second output nodes, the network of thin-film elements being coupled between the first and second output nodes and configurable using the at least one conductor to balance the first and second output nodes and amplify the two-channel output.

11. The electronic device of claim 1 wherein each configurable resistive element comprises a single multi-layer thin film element.

12. The electronic device of claim 11 wherein the single multi-layer thin film element comprises at least one high coercivity layer and at least one low coercivity layer, the resistance value associated with the single multi-layer thin film element being configurable by at least partially switching a first magnetization vector associated with the at least one high coercivity layer.

13. The electronic device of claim 1 wherein the at least one multi-layer thin film element comprises a plurality of periods of low and high coercivity layers.

14. The electronic device of claim 1 wherein the at least one multi-layer thin film element comprises a single period of low and high coercivity layers.

15. A method for configuring a configurable resistive element in an electronic device, the configurable resistive element having a resistance value associated therewith and comprising at least one multi-layer thin film element exhibiting giant magnetoresistance, the method comprising applying at least one magnetic field to the configurable resistive element which manipulates at least one magnetization vector associated with the at least one thin film element thereby configuring the resistance value.

16. The method of claim 15 wherein each thin film element of each configurable resistive element comprises at least one high coercivity layer and at least one low coercivity layer, and wherein applying the at least one magnetic field comprises partially switching a first magnetization vector associated with the at least one high coercivity layer.

17. The method of claim 15 wherein each configurable resistive element comprises a network of thin-film elements in a bridge configuration, at least one thin-film element exhibiting giant magnetoresistance, and at least one conductor inductively coupled to the at least one thin-film element for applying the at least one magnetic field thereto, the method further comprising configuring the network of thin-film elements to operate as a logic gate having an amplification factor associated therewith, and wherein applying the at least one magnetic field comprises altering the amplification factor.

18. The method of claim 15 wherein each configurable resistive element comprises a network of thin-film elements in a bridge configuration, at least one thin-film element exhibiting giant magnetoresistance, and at least one conductor inductively coupled to the at least one thin-film element for applying the at least one magnetic field thereto, the method further comprising configuring the network of thin-film elements to operate as a differential amplifier having an amplification factor associated with each of two inputs, and wherein applying the at least one magnetic field comprises altering the amplification factor associated with at least one of the two inputs.

19. The method of claim 15 wherein each configurable resistive element comprises a network of thin-film elements in a bridge configuration, at least one thin-film element exhibiting giant magnetoresistance, and at least one conductor inductively coupled to the at least one thin-film element for applying the at least one magnetic field thereto, the electronic device further comprising at least one component having a two-channel output corresponding to first and second output nodes, the network of thin-film elements being coupled between the first and second output nodes, and wherein applying the at least one magnetic field comprises balancing the first and second output nodes and amplifying the two-channel output.