Apparatuses including current compliance circuits and methods
View Patent ↗Apparatus, devices, systems, and methods are described that include variable state material data storage. Example devices include current compliance circuits that are configured to dynamically adjust a current passing through a variable resistance material during a memory operation. Some configurations utilize components within an array of memory cells to form a current compliance circuit. Additional apparatus, systems, and methods are described.
1. A memory device, comprising:
an array of memory cells having access lines and data lines, at least some of the cells including:
a variable state material component;
an access device coupled to the variable state material component and a corresponding one of the access lines;
a reference circuit, wherein the reference circuit includes a number of components formed on pitch with the access devices in the array of memory cells to provide a reference current that mirrors a data line current, wherein an operative length of a reference line in the reference circuit matches an operative length of a corresponding data line;
a current limiter coupled to the reference circuit, wherein the current limiter is configured to set an upper limit on a bias condition on the access device; and
a driver coupled to the array of memory cells to concurrently provide a set voltage and a reset voltage to different memory cells in the array at the same time.
2. The memory device of claim 1 , wherein the driver is further configured to provide an inhibit voltage to selected cells in the array at the same time as the set voltage and the reset voltage are being applied to different memory cells in the array.
3. The memory device of claim 1 , wherein the number of components of the reference current circuit includes a number of reference diodes, wherein each of the number of reference diodes is coupled to a respective one of the access lines.
4. The memory device of claim 1 , wherein the reference current circuit is configured such that an operative length of the reference line remains substantially the same as an operative length of a selected one of the data lines.
5. The memory device of claim 1 , wherein the variable state material comprises resistance switching material.
6. A memory device, comprising:
an array of memory cells having access lines and data lines, at least some of the cells including:
a variable state material component;
an access device coupled to the variable state material component and a corresponding one of the access lines;
a reference circuit, wherein the reference circuit includes a number of components formed on pitch with the access devices in the array of memory cells to provide a reference current that mirrors a data line current, wherein an operative length of a reference line in the reference circuit matches an operative length of a corresponding data line;
a current limiter coupled to the reference circuit, wherein the current limiter is configured to set an upper limit on a bias condition on the access device; and
a plurality of voltage input nodes, including a reset voltage input node and a set voltage input node, with selector circuitry to selectively couple the reset voltage input node and the set voltage input node to different memory cells in an array of memory cells at the same time.
7. The memory device of claim 6 , wherein the plurality of voltage input nodes further includes an inhibit voltage input node.
8. The memory device of claim 7 , further including a number of selector circuits with each selector circuit providing a selected voltage from the plurality of voltage input nodes to a data line.
9. The memory device of claim 8 , wherein each selector circuit includes three switches, each switch corresponding to the reset voltage input node, the set voltage input node, and the inhibit voltage input node.
10. The memory device of claim 6 , wherein the wherein the number of components of the reference current circuit includes a number of reference diodes, wherein each of the number of reference diodes is coupled to a respective one of the access lines.
11. The memory device of claim 6 , wherein the reference current circuit is configured such that an operative length of the reference line remains substantially the same as an operative length of a selected one of the data lines.
12. The memory device of claim 6 , wherein the variable state material comprises resistance switching material.
13. An information handling system, comprising:
a processor;
an array of memory cells coupled to the processor, having access lines and data lines, at least some of the cells including:
a variable state material component;
an access device coupled to the variable state material component and a corresponding one of the access lines;
a reference circuit, wherein the reference circuit includes a number of components formed on pitch with the access devices in the array of memory cells to provide a reference current that mirrors a data line current, wherein an operative length of a reference line in the reference circuit matches an operative length of a corresponding data line;
a current limiter coupled to the reference circuit, wherein the current limiter is configured to set an upper limit on a bias condition on the access device; and
a driver coupled to the array of memory cells to provide set and reset voltages to different memory cells in the array at the same time.
14. The information handling system of claim 13 , wherein the processor and array of memory cells are included in a tablet computer.
15. The information handling system of claim 13 , wherein the processor and array of memory cells are included in a cellular telephone.
16. The information handling system of claim 13 , further including a touchscreen user interface coupled to the processor.
17. The information handling system of claim 13 , wherein the driver is further configured to provide an inhibit voltage to selected cells in the array at the same time as the set voltage and the reset voltage are being applied to different memory cells in the array.
18. The information handling system of claim 13 , further including a number of selector circuits with each selector configured to provide a different selected voltage from the driver to a data line associated with the selector circuit.