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US 2010/0074015 A1Published application
Sensing for memory read and program verify operations in a non-volatile memory device
AssigneeMicron Technology, Inc.
InventorsUday Chandrasekhar, Ebrahim Abedifard, Allahyar Vahidimowlavi
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Abstract
Methods for sensing in a memory device, a memory device, and a memory system are disclosed. In one such sensing method, a single read operation with multiple sense amplifier circuit comparisons to a reference threshold level are performed to determine a state of a selected memory cell. A ramped voltage turns on the selected memory cell when the ramped voltage reaches the threshold voltage to which the selected memory cell is programmed. In one embodiment, the turned on memory cell discharges its respective bit line.
Claims31
A method for sensing in a memory device, the method comprising:
- precharging unselected memory cells to a pass voltage;
- precharging at least one data line to a first voltage level;
- grounding a source line;
- and
- applying a ramped voltage to at least one selected memory cell that turns on the at least one selected memory cell when the ramped voltage reaches a voltage level substantially equal to a threshold voltage of the at least one selected memory cell, wherein the turned on memory cell discharges the at least one data line that is coupled to the turned on memory cell.
2 more elements
A method for sensing in a non-volatile memory device, the method comprising:
- precharging unselected memory cells to a pass voltage;
- grounding a source line;
- precharging a plurality of data lines to a first voltage level;
- turning on select gate transistors, each of which couples a respective one of a plurality of selected memory cells to a different data line;
- and
- applying a ramped voltage to the plurality of selected memory cells that turns on a respective one of the selected memory cell when the ramped voltage reaches a threshold voltage for that respective one of the selected memory cells wherein a turned on memory cell discharges the data line coupled to the turned on memory cell to a second voltage level that is indicative of the threshold voltage.
3 more elements
A method for sensing in a non-volatile memory device, the method comprising:
- precharging unselected memory cells to a pass voltage that allows a maximum threshold voltage to pass;
- precharging a source line to a voltage level;
- turning on a select gate drain transistor that couples a respective one of a plurality of selected memory cells to a different data line;
- and
- applying a ramped voltage to the plurality of selected memory cells that turns on each selected memory cell when the ramped voltage reaches a threshold voltage to which each selected memory cell is programmed, wherein a turned on memory cell charges its respective data line to a voltage indicative of the threshold voltage to which the selected memory cell is programmed.
2 more elements
A non-volatile memory device comprising:
- a memory array comprising a plurality of memory cells coupled to word lines and bit lines, the memory array further comprising a source line;
- and
- memory control circuitry coupled to the memory array and configured to control a sensing operation that precharges unselected word lines, grounds the source line, turns on select gate transistors, and controls the generation of a ramped voltage coupled to a selected word line wherein each selected memory cell coupled to the selected word line are turned on when the ramped voltage reaches a threshold voltage for each selected memory cell such that each turned on memory cell discharges a bit line to which it is coupled.
A memory system comprising:
- a controller for generating memory control signals;
- and
- a non-volatile memory device coupled to the controller and operating in response to the memory control signals, the memory device comprising:
- a memory array comprising a plurality of memory cells coupled to a source line;
- and
- memory control circuitry coupled to the memory array for controlling operation of the memory array in response to the memory control signals, wherein the control circuitry is configured to control a sensing operation that precharges unselected memory cells, precharges the source line, turns on a select gate drain transistor to enable selected memory cell access to a data line, and controls a ramped voltage coupled to selected memory cells that turn on when the ramped voltage reaches a threshold voltage to which the selected memory cell is programmed such that the turned on memory cell charges its respective data line.
3 more elements
A method for sensing in a memory device, the method comprising:
- precharging unselected memory cells to a pass voltage;
- grounding at least one data line;
- precharging a source line to a voltage level;
- and
- applying a ramp voltage to at least one selected memory cell that turns on the at least one selected memory cell when the ramped voltage reaches a voltage level substantially equal to a threshold voltage of the at least one selected memory cell, wherein the turned on memory cell charges the at least one data line that is coupled to the turned on memory cell.
2 more elements
A non-volatile memory device comprising:
- a memory array comprising a plurality of memory cells coupled to word lines and bit lines, the memory array further comprising a source line;
- and
- memory control circuitry coupled to the memory array and configured to control a sensing operation that precharges unselected word lines, grounds the source line, turns on select gate transistors, and controls the generation of a ramped voltage coupled to a selected word line wherein each selected memory cell coupled to the selected word line are turned on when the ramped voltage reaches a threshold voltage for each selected memory cell such that each turned on memory cell charges a bit line to which it is coupled.
Dependencies are inferred from the claim text.