Abstract: Methods, systems, and devices for variable filter capacitance are described. Within a memory device, voltages may be applied to access lines associated with two voltage sources to increase the capacitance provided by the access lines between the two voltage sources. In some cases, the access lines may be in electronic communication with capacitive cells that include a capacitive element and a selection component, and the voltage sources and access lines may be configured to utilize the capacitive elements and the capacitance between the access lines to generate an increase capacitance between the voltage sources. In some cases, decoders may be used to implement certain configurations that generate different capacitance levels. Similarly, sub-decoders may generate different capacitance levels by selecting portions of a capacitive array.

Abstract: Methods, systems, and devices for operating a memory cell or cells are described. A capacitor coupled with an access line may be precharged and then boosted such that the charge stored in the capacitor is elevated to a higher voltage with respect to a memory cell. The boosted charge in the capacitor may support sensing operations that would otherwise require a relatively higher voltage. Some embodiments may employ charge amplification between an access line and a sense component, which may amplify signals between the memory cell and the sense component, and reduce charge sharing between these components. Some embodiments may employ “sample-and-hold” operations, which may re-use certain components of a sense component to separately generate a signal and a reference, reducing sensitivity to manufacturing and/or operational tolerances. In some embodiments, sensing may be further improved by employing “self-reference” operations that use a memory cell to generate its own reference.

Abstract: Apparatus and methods utilize a replica circuit to generate a voltage for programming of a memory cell, such as a memory cell of a phase-change memory (PCM). Current passing through a circuit including the memory cell to be programmed is mirrored in a scaled or unscaled manner, and provided as an input to the replica circuit. The replica circuit represents voltage drops that should be encountered when programming the memory cell. An input voltage is also provided to the replica circuit, which affects the voltage drop within the replica circuit that represents the voltage drop of the cell. The voltage drop across the replica circuit can then be mirrored and provided to bias the circuit including the memory cell.

Abstract: Devices and methods for sensing a memory cell are described. The memory cell may include a ferroelectric memory cell. During a read operation, a cascode may couple a precharged capacitor with the memory cell to transfer a charge between the precharged capacitor and the memory cell. The cascode may isolate the capacitor from the memory cell based on the charge transferred between the capacitor and the memory cell. A second capacitor (e.g., a parasitic capacitor) may continue to provide an additional amount of charge to the memory cell during the read operation. Such a change in capacitance value during the read operation may provide a large sense window due to a non-linear voltage characteristics associated with the change in capacitance value.

Abstract: Methods and devices for reading a memory cell using a sense amplifier with split capacitors is described. The sense amplifier may include a first capacitor and a second capacitor that may be configured to provide a larger capacitance during certain portions of a read operation and a lower capacitance during other portions of the read operation. In some cases, the first capacitor and the second capacitor are configured to be coupled in parallel between a signal node and a voltage source during a first portion of the read operation to provide a higher capacitance. The first capacitor may be decoupled from the second capacitor during a second portion of the read operation to provide a lower capacitance during the second portion.

Abstract: Apparatuses and methods for memory that includes a first memory cell including a storage component having a first end coupled to a plate line and a second end coupled to a digit line, and a second memory cell including a storage component having a first end coupled to a digit line and a second end coupled to a plate line, wherein the digit line of the second memory cell is adjacent to the plate line of the first memory cell.

Abstract: The present provision includes apparatuses, methods, and systems for charge separation for memory sensing. An embodiment includes applying a sensing voltage to a memory cell, and determining a data state of the memory cell based, at least in part, on a comparison of an amount of charge discharged by the memory cell while the sensing voltage is being applied to the memory cell before a particular reference time and an amount of charge discharged by the memory cell while the sensing voltage is being applied to the memory cell after the particular reference time.

Abstract: Methods, systems, and devices for time-based access of memory cells in a memory array are described herein. During a sense portion of a read operation, a selected memory cell may be charged to a predetermined voltage level. A logic state stored on the selected memory cell may be identified based on a duration between the beginning of the charging and when selected memory cell reaches the predetermined voltage level. In some examples, time-varying signals may be used to indicate the logic state based on the duration of the charging. The duration of the charging may be based on a polarization state of the selected memory cell, a dielectric charge state of the selected state, or both a polarization state and a dielectric charge state of the selected memory cell.

Abstract: Methods and devices for techniques for precharging a memory cell are described. Precharging a memory cell while the memory cell is coupled with its digit line may reduce a total duration of an access operation thereby reducing a latency associated with accessing a memory device. During a read operation, the memory device may select a word line to couple the memory cell with a selected digit line. Further, the memory device may selectively couple the selected digit line with a reference digit line that is to be precharged to a given voltage. A difference in voltage between the selected digit line and the reference digit line at the completion of precharging may represent a signal indicative of a logic state of the memory cell. The memory device may use a capacitor precharged to a first voltage to capture the signal.

Abstract: Methods, systems, and devices are described for operating a memory array. A first voltage may be applied to a memory cell to activate a selection component of the memory cell prior to applying a second voltage to the memory cell. The second voltage may be applied to facilitate a sensing operation once the selection component is activated. The first voltage may be applied during a first portion of an access operation and may be used in determining a threshold voltage of the selection component. The subsequently applied second voltage may be applied during a second portion of the access operation and may have a magnitude associated with a preferred voltage for accessing a ferroelectric capacitor of the memory cell. In some cases, the second voltage has a greater rate of increase over time (e.g., a greater “ramp”) than the first voltage.

Abstract: Subject matter disclosed herein relates to memory devices and, more particularly, to programming a memory cell.

Abstract: Methods, systems, and apparatuses for full bias sensing in a memory array are described. Various embodiments of an access operation of a cell in a array may be timed to allow residual charge of a middle electrode between the cell and a selection component to discharge. Access operations may also be timed to allow residual charge of middle electrodes associated with other cells to be discharged. In conjunction with an access operation for a target cell, a residual charge of a middle electrode of another cell may be discharged, and the target cell may then be accessed. A capacitor in electronic communication with a cell may be charged and a logic state of the cell determined based on the charge of the capacitor. The timing for charging the capacitor may be related to the time for discharging a middle electrode of the cell or another cell.

Abstract: Apparatus and methods utilize a replica circuit to generate a voltage for programming of a memory cell, such as a memory cell of a phase-change memory (PCM). Current passing through a circuit including the memory cell to be programmed is mirrored in a scaled or unscaled manner, and provided as an input to the replica circuit. The replica circuit represents voltage drops that should be encountered when programming the memory cell. An input voltage is also provided to the replica circuit, which affects the voltage drop within the replica circuit that represents the voltage drop of the cell. The voltage drop across the replica circuit can then be mirrored and provided to bias the circuit including the memory cell.

Abstract: Methods and devices for techniques for precharging a memory cell are described. Precharging a memory cell while the memory cell is coupled with its digit line may reduce a total duration of an access operation thereby reducing a latency associated with accessing a memory device. During a read operation, the memory device may select a word line to couple the memory cell with a selected digit line. Further, the memory device may selectively couple the selected digit line with a reference digit line that is to be precharged to a given voltage. A difference in voltage between the selected digit line and the reference digit line at the completion of precharging may represent a signal indicative of a logic state of the memory cell. The memory device may use a capacitor precharged to a first voltage to capture the signal.

Abstract: The present disclosure includes apparatuses, methods, and systems for charge separation for memory sensing. An embodiment includes applying a sensing voltage to a memory cell, and determining a data state of the memory cell based, at least in part, on a comparison of an amount of charge discharged by the memory cell while the sensing voltage is being applied to the memory cell before a particular reference time and an amount of charge discharged by the memory cell while the sensing voltage is being applied to the memory cell after the particular reference time.

Abstract: Techniques are described herein for mitigating parasitic signals induced by state transitions during an access operation of a selected memory cell in a memory device. Some memory devices may include a plate that is coupled with memory cells associated with a plurality of digit lines and/or a plurality of word lines. Because the plate is coupled with a plurality of digit lines and/or word lines, unintended coupling between various components of the memory device may occur during an access operation. To mitigate parasitic signals induced by the unintended coupling, the memory device may isolate the selected memory cell from a selected digit line during certain portions of the access operation. The memory device may isolate the selected memory cell when the plate transitions from a first voltage to a second, when the selected digit line transitions from a third voltage to a fourth voltage, or a combination thereof.

Abstract: Methods, systems, and devices are described for operating a memory array. A first voltage may be applied to a memory cell to activate a selection component of the memory cell prior to applying a second voltage to the memory cell. The second voltage may be applied to facilitate a sensing operation once the selection component is activated. The first voltage may be applied during a first portion of an access operation and may be used in determining a threshold voltage of the selection component. The subsequently applied second voltage may be applied during a second portion of the access operation and may have a magnitude associated with a preferred voltage for accessing a ferroelectric capacitor of the memory cell. In some cases, the second voltage has a greater rate of increase over time (e.g., a greater “ramp”) than the first voltage.

Abstract: Methods, systems, and devices for operating a ferroelectric memory cell or cells are described. A ground reference scheme may be employed in a digit line voltage sensing operation. A positive voltage may be applied to a memory cell; and after a voltage of the digit line of the cell has reached a threshold, a negative voltage may be applied to cause the digit line voltages to center around ground before a read operation. In another example, a first voltage may be applied to a memory cell and then a second voltage that is equal to an inverse of the first voltage may be applied to a reference capacitor that is in electronic communication with a digit line of the memory cell to cause the digit line voltages to center around ground before a read operation.

Abstract: Subject matter disclosed herein relates to memory devices and, more particularly, to programming a memory cell.

Abstract: Apparatuses and methods for memory that includes a first memory cell including a storage component having a first end coupled to a plate line and a second end coupled to a digit line, and a second memory cell including a storage component having a first end coupled to a digit line and a second end coupled to a plate line, wherein the digit line of the second memory cell is adjacent to the plate line of the first memory cell.