Patent application number | Description | Published |
20100097127 | BOOSTER CIRCUIT AND VOLTAGE SUPPLY CIRCUIT - A voltage supply circuit includes a booster circuit and a ripple filter circuit. The ripple filter circuit has a first resistor connected to a first output terminal at one end thereof. The ripple filter circuit also has a first switch circuit connected between the other end of the first resistor and a second output terminal. In addition, the ripple filter circuit has a second switch circuit connected between the first output terminal of the booster circuit and the first switch circuit. | 04-22-2010 |
20100097860 | NAND FLASH MEMORY - A NAND flash memory, in a read operation, a p-type semiconductor substrate is set at a ground potential, a bit line is charged to a first voltage, a source line, a n-type well and a p-type well are charged to a second voltage, which lies between a ground potential and a first voltage, and in a block not selected by said row decoder, said drain-side select gate line and said source-side select gate line are charged to a third voltage, which is higher than said ground potential and is equal to or lower than said second voltage. | 04-22-2010 |
20100208510 | SEMICONDUCTOR MEMORY DEVICE AND METHOD OF OPERATING THE SAME - A semiconductor memory device comprises: a memory cell array having memory cells disposed at a crossing-point of a plurality of first lines and a plurality of second lines; and a control circuit configured to apply a first voltage to selected one of the first lines, and to apply a second voltage to selected one of the second lines. The control circuit comprises: a first isolation latch circuit configured to set the first lines to a floating state; and a second isolation latch circuit configured to set the second lines to the floating state. During a forming operation, the first and second isolation latch circuits set one of the first lines and one of the second lines to which a defective memory cell is connected to the floating state, the defective memory cell being one of the memory cells that allows a current to flow due to application of a voltage. | 08-19-2010 |
20100214820 | SEMICONDUCTOR MEMORY DEVICE - A semiconductor memory device comprises: a memory cell array having memory cells disposed at a crossing-point of a plurality of first lines and a plurality of second lines and a control circuit configured to apply a first voltage to selected one or more of the first lines, and to apply a second voltage having a value smaller than the first voltage to selected one of the second lines, such that a certain potential difference is applied to selected one or more of the memory cells. The control circuit adjusts the second voltage based on a position of the selected one or more of the memory cells within the memory cell array and a number of the selected one or more of the memory cells on which an operation is simultaneously executed, during application of the potential difference to the selected one or more of the memory cells. | 08-26-2010 |
20110069533 | RESISTANCE CHANGE MEMORY AND CONTROL METHOD THEREOF - According to one embodiment, a resistance change memory includes a memory cell array in which a plurality of blocks are provided, resistance change storage elements which are provided in blocks and which store data in accordance with a change in resistance state, first and second wirings in the blocks, each of the first and second wirings being connected to each of resistance change storage elements, and a control circuit which controls the state of a selected block targeted for operation and the state of unselected blocks except the selected block among the blocks. The control circuit respectively applies first and second unselect potentials to the first and second wirings in at least one of the unselected blocks during a period in which the selected block is in operation. | 03-24-2011 |
20110116300 | NONVOLATILE SEMICONDUCTOR MEMORY DEVICE - A nonvolatile semiconductor memory device according to an embodiment comprises a memory cell array including plural mutually crossing first and second lines and memory cells arranged at intersections of the first and second lines, each memory cell containing a variable resistance element and a rectifier element connected in series; and a data write/erase circuit operative to apply a voltage required for data write/erase to the memory cell via the first and second lines. The data write/erase circuit includes a first current limit circuit operative to limit the current flowing in the cathode-side line provided on the cathode side of the rectifier element, of the first and second lines, at the time of data write/erase. | 05-19-2011 |
20110140766 | BOOSTER CIRCUIT AND VOLTAGE SUPPLY CIRCUIT - A booster circuit includes a pump circuit having a plurality of charge pump circuits for outputting a boosted voltage to a first output terminal. The booster circuit also includes a clock adjusting circuit that generates, from a first clock signal, a second clock signal for operating the charge pump circuits. A pump controlling circuit outputs the first clock signal for operating the pump circuit. A first comparator outputs a first output signal. A second comparator outputs a second output signal. A third comparator outputs a third output signal. A gradient of the boosted voltage is decreased when the first output signal is output. A frequency of the first clock signal is reduced when the second output signal is output. The third output signal is output when the boosted voltage is higher than a set value of the boosted voltage. | 06-16-2011 |
20110149653 | NAND FLASH MEMORY - A NAND flash memory, in a read operation, a p-type semiconductor substrate is set at a ground potential, a bit line is charged to a first voltage, a source line, a n-type well and a p-type well are charged to a second voltage, which lies between a ground potential and a first voltage, and in a block not selected by said row decoder, said drain-side select gate line and said source-side select gate line are charged to a third voltage, which is higher than said ground potential and is equal to or lower than said second voltage. | 06-23-2011 |
20120026778 | SEMICONDUCTOR STORAGE DEVICE - A semiconductor memory device includes: a memory cell array including multiple first lines, multiple second lines crossing the first lines, and memory cells arranged at intersections between the first lines and the second lines and including variable resistive elements; and a control circuit which controls resistance values of the variable resistive elements in a way that a cell voltage is applied to the memory cell arranged at an intersection between a selected first line and a selected second line by applying first and second voltages to the selected first and second lines, respectively. The control circuit applies a voltage gradually raised or lowered from a first initial voltage as the first voltage to the selected first line, and a pulsing voltage as the second voltage to the selected second line. The second voltage includes a voltage pulse which is raised from a second initial voltage to turn the memory cell into a non-selected state to a voltage to turn the memory cell into a selected state, is kept at the raised voltage to thereby cause a cell current to flow into the memory cell, and is lowered to the second initial voltage when the cell current that increases while the voltage of the memory cell is rising with a change in the first voltage reaches a predetermined compliance current. | 02-02-2012 |
20120039110 | SEMICONDUCTOR MEMORY DEVICE - A memory-cell array that includes a first line, a second line intersecting the first line, and a memory cell including a variable resistive element provided in the intersection of the first and the second lines; a data-write unit configured to apply a voltage pulse to the memory cell through the first and the second lines, the voltage pulse to set and/or reset data; and a detector unit configured to compare a cell current that flows through the memory cell by the voltage pulse at the time of setting and/or resetting the data with a reference current generated from the initial value of the cell current, and to control the data-write unit in accordance with a result of comparison. | 02-16-2012 |
20120092928 | SEMICONDUCTOR MEMORY DEVICE - A semiconductor memory device includes: a memory-cell array provided between a first region and a second region, and including a plurality of memory cells; a first row decoder and a second row decoder; a first power line provided in the first region; a second power line provided in the first region; a first power-supply circuit configured to supply the first voltage to the first power line and to the second power line; a first switching circuit; and a second switching circuit. In a write operation, the first switching circuit connects the first power line and the first power-supply circuit to each other whereas the second switching circuit disconnects the second power line and the first power-supply circuit from each other. | 04-19-2012 |
20120133425 | BOOSTER CIRCUIT AND VOLTAGE SUPPLY CIRCUIT - A booster circuit includes a pump circuit having a plurality of charge pump circuits that output a boosted voltage. The booster circuit also includes a clock adjusting circuit that generates a second clock signal for operating the charge pump circuits from a first clock signal to a first output terminal. The booster circuit additionally includes a pump controlling circuit that outputs the first clock signal for operating the pump circuit, a first comparator that outputs a first output signal, a second comparator that outputs a second output signal, and a third comparator that outputs a third output signal. A gradient of the boosted voltage is decreased when the first output signal is output. A frequency of the first clock signal is reduced when the second output signal is output. The third output signal is output when the boosted voltage is higher than a set value of the boosted voltage. | 05-31-2012 |
20120307562 | NONVOLATILE SEMICONDUCTOR MEMORY DEVICE - A nonvolatile semiconductor memory device according to an embodiment includes: a semiconductor substrate; a memory cell array including a plurality of memory cells, the memory cells being stacked on the semiconductor substrate; and a power supply circuit provided on the semiconductor substrate. The power supply circuit includes: a pump circuit configured to generate a voltage and supply the voltage to the memory cell array; a limiter circuit configured to output control signal for activating the pump circuit according to a comparison result between a voltage value of the output terminal and a first value; a capacitor configured to adjust a voltage of the output terminal; a boost circuit configured to charge the capacitor using a constant current based on the control signal; and a switch configured to stop a charge operation of the boost circuit. The capacitor is provided directly below the memory cell array. | 12-06-2012 |
20120320678 | NON-VOLATILE SEMICONDUCTOR MEMORY DEVICE - In performing a read operation of a memory transistor, a control circuit supplies a first voltage to a selected word line connected to a selected memory transistor. A second voltage is supplied to a non-selected word line connected to a non-selected memory transistor other than the selected memory transistor, the second voltage being higher than the first voltage. A third voltage is supplied to a bit line. A fourth voltage lower than the third voltage is supplied to, among source lines, a selected source line connected to a memory string including the selected memory transistor in a selected memory block. A fifth voltage substantially the same as the third voltage is supplied to, among the source lines, a non-selected source line connected to a non-selected memory string in the selected memory block. | 12-20-2012 |
20130028020 | NAND FLASH MEMORY - A NAND flash memory, in a read operation, a p-type semiconductor substrate is set at a ground potential, a bit line is charged to a first voltage, a source line, a n-type well and a p-type well are charged to a second voltage, which lies between a ground potential and a first voltage, and in a block not selected by said row decoder, said drain-side select gate line and said source-side select gate line are charged to a third voltage, which is higher than said ground potential and is equal to or lower than said second voltage. | 01-31-2013 |
20130058165 | SEMICONDUCTOR MEMORY DEVICE - According to one embodiment, a semiconductor memory device includes a memory cells, a selection transistor, a memory string, a block, and a transfer circuit. The memory cells are stacked on a semiconductor substrate. In the memory string, the memory cells and the selection transistor are connected in series. The block includes a plurality of memory strings. In data write and read, the transfer circuit transfers a positive voltage to a select gate line associated with a selected memory string in a selected block, and a negative voltage to a select gate line associated with an unselected memory string in the selected block, and to a select gate line associated with an unselected block. | 03-07-2013 |
20130058166 | SEMICONDUCTOR MEMORY DEVICE - According to one embodiment, a semiconductor memory device includes memory cells, word lines, a driver circuit, and a control circuit. The memory cells are stacked above a semiconductor substrate, and each includes a charge accumulation layer and control gate. The word lines are coupled to the control gates. The driver circuit repeats a programming operation to write data in a memory cell coupled to a selected word line. In the programming operation, a first voltage is applied to the selected word line, a second voltage to a first unselected word line, and a third voltage to a second unselected word line. The control circuit steps up the first voltage and steps down the second voltage in repeating the programming. | 03-07-2013 |
20130155778 | NONVOLATILE SEMICONDUCTOR MEMORY DEVICE - According to one embodiment, a nonvolatile semiconductor memory device comprises a semiconductor substrate, memory strings formed above the semiconductor substrate, and a control circuit configured to control voltages applied to the memory cells. In a read operation, when the control circuit precharges a first source line electrically connected to a selected memory string to a first voltage, the control circuit precharges a second source line electrically connected to an unselected memory string to a second voltage, the second voltage being higher than the first voltage, and after the second source line is precharged, the control circuit precharges a first bit line electrically connected to the selected memory string to the second voltage. | 06-20-2013 |
20130332659 | SEMICONDUCTOR STORAGE DEVICE AND CONTROLLER - A semiconductor storage device includes memory cells, select transistors, memory strings, first and second blocks, word lines, and select gate lines. In the memory string, the current paths of plural memory cells are connected in series. When data are written in a first block, after a select gate line connected to the gate of a select transistor of one of the memory strings in the first block is selected, the data are sequentially written in the memory cells in the memory string connected to the selected select gate line. When data are written in the second block, after a word line connected to the control gates of memory cells of different memory strings in the second block is selected, the data are sequentially written in the memory cells of the different memory strings in the second block which have their control gates connected to the selected word line. | 12-12-2013 |
20140003149 | SEMICONDUCTOR STORAGE DEVICE | 01-02-2014 |
20140153337 | SEMICONDUCTOR MEMORY DEVICE - According to one embodiment, a semiconductor memory device includes memory cells, word lines, a driver circuit, and a control circuit. The memory cells are stacked above a semiconductor substrate, and each includes a charge accumulation layer and control gate. The word lines are coupled to the control gates. The driver circuit repeats a programming operation to write data in a memory cell coupled to a selected word line. In the programming operation, a first voltage is applied to the selected word line, a second voltage to a first unselected word line, and a third voltage to a second unselected word line. The control circuit steps up the first voltage and steps down the second voltage in repeating the programming. | 06-05-2014 |
20140233320 | NONVOLATILE SEMICONDUCTOR MEMORY DEVICE - A nonvolatile semiconductor memory device includes a memory cell, a bit line electrically connected to the memory cell, a sense amplifier that includes a first transistor having a first end electrically connected to the bit line, a second transistor electrically connected between a second end of the first transistor and ground, a third transistor electrically connected between a second end of the first transistor and a source line, and a controller configured to control the first, second, and third transistors after performing a program operation. After the program operation, the first and second transistors are turned on and then while the first transistor remains turned on, the second transistor is turned off and the third transistor is turned on. | 08-21-2014 |
20140247671 | SEMICONDUCTOR MEMORY DEVICE - According to one embodiment, a semiconductor memory device includes a first sub-array including a plurality of first memory cells; a second sub-array including a plurality of second memory cells; a first bit line electrically connected to a first group of the first memory cells; a second bit line electrically connected to a first group of the second memory cells; a bit line connection unit configured to connect the first bit line and the second bit line; a first sense amplifier configured to receive a first voltage from either of the first bit line and the second bit line in a read operation, and transfer a second voltage either of the first bit line and the second bit line in a write operation; a first source line electrically connected to the first memory cells; a second source line electrically connected to the second memory cells; and a source line driver configured to apply voltages to the first source line and the second source line. | 09-04-2014 |
20140254270 | SEMICONDUCTOR MEMORY DEVICE AND DATA WRITING METHOD OF THE SAME - A semiconductor memory device includes memory cells which are laminated on a semiconductor substrate and include charge storage layers and control gates, a plurality of word lines each of which is commonly connected to the control gates of a plurality of the memory cells, and a control unit which performs programming and verification of data in units of a page of memory cells. The control unit consecutively performs programming of data in two or more pages of memory cells connected to the same word line, and then consecutively performs verification of the data programmed in the two or more pages of memory cells connected to the same word line. | 09-11-2014 |
20140269093 | SEMICONDUCTOR MEMORY DEVICE - A semiconductor memory device includes a sense amplifier, and the sense amplifier includes a bus, first and second latch circuits, and a third transistor. The first latch circuit includes a first transistor connected to the bus, and the second latch circuit includes a second transistor connected to the bus. When data is transmitted from the first latch circuit to the second latch circuit, a third transistor is switched on to precharge the bus by applying a first voltage that is lower than a power source voltage of the first and second latch circuits to a gate of the third transistor. Thereafter, second and third voltages that are lower than the power source voltage are applied to gates of first and second transistors, respectively. | 09-18-2014 |
20140269095 | SEMICONDUCTOR STORAGE - A semiconductor storage includes memory cells, a bit line, and a sense amplifier having a first transistor that controls precharging of the bit line, a second transistor that controls charging of a first node, a third transistor that controls connection of the bit line to the first node, a fourth transistor that controls connection of the first node to a second node, a fifth transistor that controls connection of the first node to a third node, and a sixth transistor that is controlled to sense a potential of the third node. The controller controls the first through sixth transistors of data to perform a read operation based on the potential of the third node. | 09-18-2014 |
20140355349 | SEMICONDUCTOR MEMORY DEVICE - According to one embodiment, a semiconductor memory device includes a memory cells, a selection transistor, a memory string, a block, and a transfer circuit. The memory cells are stacked on a semiconductor substrate. In the memory string, the memory cells and the selection transistor are connected in series. The block includes a plurality of memory strings. In data write and read, the transfer circuit transfers a positive voltage to a select gate line associated with a selected memory string in a selected block, and a negative voltage to a select gate line associated with an unselected memory string in the selected block, and to a select gate line associated with an unselected block. | 12-04-2014 |
20150049553 | SEMICONDUCTOR MEMORY DEVICE - A semiconductor memory device includes a memory cell, a sense amplifier electrically connected to the memory cell, the sense amplifier including a node for sensing a voltage during a sense operation and a data latch electrically connected to the node and configured to hold a first voltage corresponding to a voltage of the node when a strobe signal is issued during a strobe operation, and a controller configured to raise the voltage of the node during the strobe operation before the strobe signal is issued. | 02-19-2015 |