# US 10,373,680 B2 · Controlling current through correlated electron switch elements during programming operations > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,373,680 B2 - Document ID: US10373680B2 - Status: Granted - Kind: B2 - Application number: 15/590,987 - Filed: 2017-05-09 - Published: 2018-11-15 - Granted: 2019-08-06 - Earliest claimed: 2017-05-09 - Assignees: Arm Limited - Applicants: ARM Ltd. - Inventors: Mudit Bhargava; Glen Arnold Rosendale; Akshay Kumar; Piyush Agarwal; Shidhartha Das - Web page: https://patentgrep.com/patent/US10373680B2 ## CPC - G11C 13/0069: {Writing or programming circuits or methods} - G11C 13/0007: {comprising metal oxide memory material, e.g. perovskites} - G11C 2013/0078: {Write using current through the cell} - G11C 2213/74: Array wherein each memory cell has more than one access device - G11C 2213/79: Array wherein the access device being a transistor - G11C: STATIC STORES (semiconductor memory devices H10B) ## Abstract Subject matter disclosed herein may relate to correlated electron switch elements and, more particularly, to controlling current through correlated electron switch elements during programming operations. ## Claims ### Claim 1 A method, comprising: performing a write operation to place a correlated electron switch device in a lower impedance state comprising controlling a current through the correlated electron switch device, at least in part by limiting a voltage applied to an access device coupled to the correlated electron switch device to a specified threshold voltage level, at least in part to establish a threshold current density level in the correlated electron switch device for a subsequent write operation to place the correlated electron switch device in a higher impedance state. ### Claim 2 (depends on 1) The method of claim 1, wherein the performing the write operation to place the correlated electron switch device in the lower impedance state further comprises applying a first programming voltage across the correlated electron switch device and the access device. ### Claim 3 (depends on 2) The method of claim 2, further comprising performing the subsequent write operation to place the correlated electron switch device in the higher impedance state, including: applying a second programming voltage across the correlated electron switch device and the access device, wherein the second programming voltage is lower in level than the first programming voltage; and controlling the current through the correlated electron switch device such that a current density in the correlated electron switch device to exceed the threshold current density level at least in part by controlling the voltage applied to the access device. ### Claim 4 (depends on 3) The method of claim 3, wherein the access device comprises a field-effect transistor. ### Claim 5 (depends on 3) The method of claim 3, wherein the limiting the voltage applied to the access device to the specified threshold voltage level at least in part to establish the threshold current density level in the correlated electron device for the subsequent write operation comprises locally throttling the current through the correlated electron switch device at least in part via controlling the voltage applied to the access device. ### Claim 6 (depends on 5) The method of claim 5, wherein the locally throttling the current through the correlated electron switch device comprises under-driving the access device. ### Claim 7 (depends on 6) The method of claim 6, wherein the access device comprises an electronic switch, and wherein the under-driving the access device comprises enabling the electronic switch via an enable signal that is lower in voltage level than the first programming voltage. ### Claim 8 (depends on 7) The method of claim 7, wherein the enable signal is applied to the electronic switch via a word-line. ### Claim 9 (depends on 4) The method of claim 4, wherein the limiting the voltage applied to the access device to the specified threshold voltage level at least in part to establish the threshold current density level in the correlated electron device for the subsequent write operation comprises globally throttling the current through the correlated electron switch device. ### Claim 10 (depends on 9) The method of claim 9, wherein the globally throttling the current through the correlated electron switch device comprises adjusting the current level via one or more write driver circuits or via one or more voltage supplies, or a combination thereof. ### Claim 11 An apparatus, comprising: one or more correlated electron switch devices; and one or more electronic switch devices to control a current through the one or more correlated electron switch devices during a write operation to place the one or more correlated electron switch devices in a lower impedance state to limit the current to a specified threshold current level at least in part to establish a threshold current density in the one or more correlated electron switch devices for a subsequent write operation to place the one or more correlated electron switch devices in a higher impedance state. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein, to perform the write operation to place the one or more correlated electron switch devices in the lower impedance state, a first programming voltage to be applied across the one or more correlated electron switch devices and the one or more electronic switch devices. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein, to perform the subsequent write operation to place the one or more correlated electron switch devices in the higher impedance state, a second programming voltage to be applied across the one or more correlated electron switch devices and the one or more electronic switch devices, the second programming voltage to be lower in level than the first programming voltage, wherein the current density in the correlated electron switch devices to exceed the established threshold current density level. ### Claim 14 (depends on 13) The apparatus of claim 13, wherein the one or more electronic switch devices to individually comprise one or more field-effect transistors. ### Claim 15 (depends on 13) The apparatus of claim 13, wherein, to control the current through the one or more correlated electron switch devices, the current through the one or more correlated electron switch devices to be locally throttled at least in part via control of a voltage applied to one or more gate terminals of the one or more field-effect transistors. ### Claim 16 (depends on 15) The apparatus of claim 15, wherein, to locally throttle the current through the one or more correlated electron switch devices, the one or more field-effect transistors to be under-driven. ### Claim 17 (depends on 16) The apparatus of claim 16, wherein, to under-drive the one or more field-effect transistors, the one or more field-effect transistors to be enabled at least in part via an enable signal to be lower in voltage level than the first programming voltage. ### Claim 18 (depends on 17) The apparatus of claim 17, wherein the enable signal to be applied to the one or more field-effect transistors via one or more word-lines. ### Claim 19 (depends on 13) The apparatus of claim 13, wherein, to control the current through the one or more correlated electron switch devices, the current through the one or more correlated electron switch devices to be globally throttled. ### Claim 20 (depends on 19) The apparatus of claim 19, wherein, to globally throttle the current through the one or more correlated electron switch devices, the current level through the one or more correlated electron switch devices to be adjusted via one or more write driver circuits or via one or more voltage supplies, or a combination thereof.