GLOBAL BIT LINE PRE-CHARGE CIRCUIT THAT COMPENSATES FOR PROCESS, OPERATING VOLTAGE, AND TEMPERATURE VARIATIONS
First Claim
1. A method of operating a cross point memory array comprising a plurality of word lines and a plurality of bit lines, wherein the plurality of bit lines comprises a plurality of local bit lines, each electrically connected to a corresponding one of a plurality of global bit lines by respective corresponding one of a plurality of gain stage transistors, the plurality of gain stage transistors having parameters that vary with respect to at least one of process, voltage, and temperature, the method comprising:
- precharging a first selected local bit line of the plurality of local bit lines to a first voltage that varies with the transistor parameters of the corresponding gain stage transistor; and
after precharging the first selected local bit line, applying a voltage to a selected word line of the cross point memory array to read a memory cell coupled between the selected local bit line and the selected word line.
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Accused Products
Abstract
A memory array includes wordlines, local bitlines, two-terminal memory elements, global bitlines, and local-to-global bitline pass gates and gain stages. The memory elements are formed between the wordlines and local bitlines. Each local bitline is selectively coupled to an associated global bitline, by way of an associated local-to-global bitline pass gate. During a read operation when a memory element of a local bitline is selected to be read, a local-to-global gain stage is configured to amplify a signal on or passing through the local bitline to an amplified signal on or along an associated global bitline. The amplified signal, which in one embodiment is dependent on the resistive state of the selected memory element, is used to rapidly determine the memory state stored by the selected memory element. The global bit line and/or the selected local bit line can be biased to compensate for the Process Voltage Temperature (PVT) variation.
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Citations
18 Claims
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1. A method of operating a cross point memory array comprising a plurality of word lines and a plurality of bit lines, wherein the plurality of bit lines comprises a plurality of local bit lines, each electrically connected to a corresponding one of a plurality of global bit lines by respective corresponding one of a plurality of gain stage transistors, the plurality of gain stage transistors having parameters that vary with respect to at least one of process, voltage, and temperature, the method comprising:
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precharging a first selected local bit line of the plurality of local bit lines to a first voltage that varies with the transistor parameters of the corresponding gain stage transistor; and after precharging the first selected local bit line, applying a voltage to a selected word line of the cross point memory array to read a memory cell coupled between the selected local bit line and the selected word line. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A memory device, comprising:
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a plurality of word lines and a plurality of bit lines, wherein the plurality of bit lines comprises a plurality of local bit lines, each electrically connected to a corresponding one of a plurality of global bit lines by respective corresponding one of a plurality of gain stage transistors, the plurality of gain stage transistors having transistor parameters that vary with at least one of process, voltage, and temperature; a plurality of two-terminal memory elements, each two-terminal memory element coupled between a respective word line of the plurality of word lines and a respective bit line of the plurality of bit lines; a controller coupled to the plurality of gain stage transistors, the controller configured to; precharge a first selected local bit line of the plurality of bit lines to a first voltage that varies with the transistor parameters of the corresponding gain stage transistor; and after precharging the first selected local bit line, applying a voltage to a selected word line of the cross point memory array to read the memory element coupled between the first selected local bit line and the selected word line. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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Specification