| Patent application number | Description | Published |
|---|
| 20080247228 | NON-VOLATILE STORAGE WITH CURRENT SENSING OF NEGATIVE THRESHOLD VOLTAGES - A non-volatile storage device in which current sensing is performed for a non-volatile storage element with a negative threshold voltage. A control gate read voltage is applied to a selected word line of a non-volatile storage element, and source and p-well voltages are applied to a source and a p-well, respectively, associated with the non-volatile storage element. The source and p-well voltages exceed the control gate read voltage so that a positive control gate read voltage can be used. There is no need for a negative charge pump to apply a negative word line voltage even for sensing a negative threshold voltage. A programming condition of the non-volatile storage element is determined by sensing a voltage drop which is tied to a fixed current which flows in a NAND string of the non-volatile storage element. | 10-09-2008 |
| 20080247229 | NON-VOLATILE STORAGE USING CURRENT SENSING WITH BIASING OF SOURCE AND P-Well - A non-volatile storage device in which current sensing is performed for a non-volatile storage element. A voltage is applied to a selected word line of the first non-volatile storage element, and source and p-well voltages are applied to a source and a p-well, respectively, associated with the non-volatile storage element. The source and p-well voltages are regulated at respective positive DC levels to avoid a ground bounce, or voltage fluctuation, which would occur if the source voltage at least was regulated at a ground voltage. A programming condition of the non-volatile storage element is determined by sensing a current in a NAND string of the non-volatile storage element. The sensing can occur quickly since there is no delay in waiting for the ground bounce to settle. | 10-09-2008 |
| 20080247238 | METHOD FOR SENSING NEGATIVE THRESHOLD VOLTAGES IN NON-VOLATILE STORAGE USING CURRENT SENSING - Current sensing is performed in a non-volatile storage device for a selected non-volatile storage element with a negative threshold voltage. A control gate read voltage is applied to a selected word line of a non-volatile storage element, and source and p-well voltages are applied to a source and a p-well, respectively, associated with the non-volatile storage element. The source and p-well voltages exceed the control gate read voltage so that a positive control gate read voltage can be used. There is no need for a negative charge pump to apply a negative word line voltage even for sensing a negative threshold voltage. A programming condition of the non-volatile storage element is determined by sensing a voltage drop which is tied to a fixed current which flows in a NAND string of the non-volatile storage element. | 10-09-2008 |
| 20080247239 | METHOD FOR CURRENT SENSING WITH BIASING OF SOURCE AND P-WELL IN NON-VOLATILE STORAGE - Current sensing is performed in a non-volatile storage device for a non-volatile storage element. A voltage is applied to a selected word line of the first non-volatile storage element, and source and p-well voltages are applied to a source and a p-well, respectively, associated with the non-volatile storage element. The source and p-well voltages are regulated at respective positive DC levels to avoid a ground bounce, or voltage fluctuation, which would occur if the source voltage at least was regulated at a ground voltage. A programming condition of the non-volatile storage element is determined by sensing a current in a NAND string of the non-volatile storage element. The sensing can occur quickly since there is no delay in waiting for the ground bounce to settle. | 10-09-2008 |
| 20080247241 | SENSING IN NON-VOLATILE STORAGE USING PULLDOWN TO REGULATED SOURCE VOLTAGE TO REMOVE SYSTEM NOISE - A pull down circuit pulls a bit line voltage to a regulated source voltage in a non-volatile storage device during a sense operation such as a verify operation which occurs during programming. The storage device may include NAND strings which have associated bit lines and sense components, and a common source line. When a selected storage element of a NAND string has been programmed to its intended state, the bit line is locked out during subsequent verify operations which occur for other NAND strings which are not yet locked out. The pull down device is coupled to each bit line and to the common source line, whose voltage is regulated at a positive DC level, to prevent coupling of system power bus (V | 10-09-2008 |
| 20080247253 | NON-VOLATILE STORAGE WITH TEMPERATURE COMPENSATION FOR BIT LINE DURING SENSE OPERATIONS - A non-volatile storage system in which temperature compensation of a bit line voltage is provided during a sense operation of a non-volatile storage element. A gate voltage of a transistor which couples a bit line associated with the non-volatile storage element to a sense module is temperature-compensated so that it is higher when temperature is higher to compensate for variations with temperature of the bit line voltage. The bit line voltage, in turn, varies due to variations in temperature of a threshold voltage of the non-volatile storage element. The sense module determines a programming condition of the non-volatile storage element, which may be provided in a NAND string, by sensing a voltage. The sense operation may be a read operation, verify operation, or erase-verify operation, for instance. Further, the threshold voltage of the non-volatile storage element may be positive or negative. In another aspect, a source voltage is temperature compensated. | 10-09-2008 |
| 20080247254 | METHOD FOR TEMPERATURE COMPENSATING BIT LINE DURING SENSE OPERATIONS IN NON-VOLATILE STORAGE - Temperature-compensation is provided during a sense operation of a non-volatile storage element. A gate voltage of a transistor which couples a bit line associated with the non-volatile storage element to a sense module is temperature-compensated so that it is higher when temperature is higher to compensate for variations with temperature of the bit line voltage. The bit line voltage, in turn, varies due to variations in temperature of a threshold voltage of the non-volatile storage element. The sense module determines a programming condition of the non-volatile storage element, which may be provided in a NAND string, by sensing a voltage. The sense operation may be a read operation, verify operation, or erase-verify operation, for instance. Further, the threshold voltage of the non-volatile storage element may be positive or negative. In another aspect, a source voltage is temperature compensated. | 10-09-2008 |
| 20080266963 | COMPENSATING SOURCE VOLTAGE DROP IN NON-VOLATILE STORAGE - A source line bias error caused by a voltage drop in a source line of a non-volatile memory device during a read or verify operation is addressed. In one approach, a body bias is applied to a substrate of the non-volatile memory device by coupling the substrate to a source voltage or a voltage which is a function of the source voltage. In another approach, a control gate voltage and/or drain voltage, e.g., bit line voltage, are compensated by referencing them to a voltage which is based on the source voltage instead of to ground. Various combinations of these approaches can be used as well. During other operations, such as programming, erase-verify and sensing of negative threshold voltages, the source line bias error is not present, so there is no need for a bias or compensation. A forward body bias can also be compensated. | 10-30-2008 |
| 20080266964 | NON-VOLATILE STORAGE WITH COMPENSATION FOR SOURCE VOLTAGE DROP - A source line bias error caused by a voltage drop in a source line of a non-volatile memory device during a read or verify operation is addressed. In one approach, a body bias is applied to a substrate of the non-volatile memory device by coupling the substrate to a source voltage or a voltage which is a function of the source voltage. In another approach, a control gate voltage and/or drain voltage, e.g., bit line voltage, are compensated by referencing them to a voltage which is based on the source voltage instead of to ground. Various combinations of these approaches can be used as well. During other operations, such as programming, erase-verify and sensing of negative threshold voltages, the source line bias error is not present, so there is no need for a bias or compensation. A forward body bias can also be compensated. | 10-30-2008 |
| 20090003068 | METHOD FOR SOURCE BIAS ALL BIT LINE SENSING IN NON-VOLATILE STORAGE - Bit line-to-bit line noise is discharged in a NAND string prior to sensing a programming condition of a selected non-volatile storage element in the NAND string. A source voltage is applied which boosts the voltage in conductive NAND strings. The voltage boost results in capacitive coupling of noise to neighboring NAND strings. A current pull down device is used to discharge each NAND string prior to performing sensing. After each NAND string is coupled to a discharge path for a predetermined amount of time, bit lines of the NAND string are coupled to voltage sense components for sensing the programming condition of the selected non-volatile storage elements based on a potential of the bit lines. The selected non-volatile storage elements may have a negative threshold voltage. Further, a word line associated with the selected non-volatile storage elements may be set at ground. | 01-01-2009 |
| 20090003069 | NON-VOLATILE STORAGE WITH SOURCE BIAS ALL BIT LINE SENSING - A NAND string in which bit line-to-bit line noise is discharged prior to sensing a programming condition of a selected non-volatile storage element in the NAND string. A source voltage is applied which boosts the voltage in conductive NAND strings. The voltage boost results in capacitive coupling of noise to neighboring NAND strings. A current pull down device is used to discharge each NAND string prior to performing sensing. After each NAND string is coupled to a discharge path for a predetermined amount of time, bit lines of the NAND string are coupled to voltage sense components for sensing the programming condition of the selected non-volatile storage elements based on a potential of the bit lines. The selected non-volatile storage elements may have a negative threshold voltage. Further, a word line associated with the selected non-volatile storage elements may be set at ground. | 01-01-2009 |
| 20090168540 | Low Noise Sense Amplifier Array and Method for Nonvolatile Memory - In sensing a page of nonvolatile memory cells with a corresponding group of sense modules in parallel, as each high current cell is identified, it is locked out from further sensing while others in the page continued to be sensed. The sense module involved in the locked out is then in a lockout mode and becomes inactive. A noise source from the sense module becomes significant when in the lockout mode. The noise is liable to interfere with the sensing of neighboring cells by coupling through its bit line to neighboring ones. The noise can also couple through the common source line of the page to affect the accuracy of ongoing sensing of the cells in the page. Improved sense modules and method isolate the noise from the lockout sense module from affecting the other sense modules still active in sensing memory cell in the page. | 07-02-2009 |
| 20090296488 | High Speed Sense Amplifier Array and Method for Nonvolatile Memory - Sensing circuits for sensing a conduction current of a memory cell among a group of non-volatile memory cells being sensed in parallel and providing the result thereof to a data bus are presented. A precharge circuit is coupled to a node for charging the node to an initial voltage. An intermediate circuit is also coupled to the node and connectable to the memory cell, whereby current from the precharge circuit can be supplied to the memory cell. The circuit also includes a comparator circuit to perform a determination the conduction current by a rate of discharge at the node; a data latch coupled to the comparator circuit to hold the result of said determination; and a transfer gate coupled to the data latch to supply a result latched therein to the data bus independently of the node. This arrangement improves sensing performance and can help to eliminate noise on the analog sensing path during sensing and reduce switching current. | 12-03-2009 |
| 20090323420 | MINIMIZING POWER NOISE DURING SENSING IN MEMORY DEVICE - In a sensing method, accuracy of sensing operations, such as read or verify, in a memory device is improved by avoiding fluctuations in a sense amp supply voltage which can occur when different sense amps are strobed at different times. First and second sets of sense amps perform a sensing operation on respective storage elements, such as in an all bit line configuration. The first set of sense amps is strobed at a first time point. In response, a sensed analog level is converted to digital data. The A/D conversion relies on the sense amp supply voltage being accurate. To avoid a fluctuation in the sense amp supply voltage, a bypass path allows the storage elements associated with the first set of sense amps to continue to draw power from the sense amp supply voltage. The second set of sense amps is strobed at a later, second time point. | 12-31-2009 |
| 20090323421 | MEMORY DEVICE WITH POWER NOISE MINIMIZATION DURING SENSING - Accuracy of sensing operations, such as read or verify, in a memory device is improved by avoiding fluctuations in a sense amp supply voltage which can occur when different sense amps are strobed at different times. First and second sets of sense amps perform a sensing operation on respective storage elements, such as in an all bit line configuration. The first set of sense amps is strobed at a first time point. In response, a sensed analog level is converted to digital data. The A/D conversion relies on the sense amp supply voltage being accurate. To avoid a fluctuation in the sense amp supply voltage, a bypass path allows the storage elements associated with the first set of sense amps to continue to draw power from the sense amp supply voltage. The second set of sense amps is strobed at a later, second time point. | 12-31-2009 |
| 20100008148 | Low Noise Sense Amplifier Array and Method for Nonvolatile Memory - In sensing a page of nonvolatile memory cells with a corresponding group of sense modules in parallel, as each high current cell is identified, it is locked out from further sensing while others in the page continued to be sensed. The sense module involved in the locked out is then in a lockout mode and becomes inactive. A noise source from the sense module becomes significant when in the lockout mode. The noise is liable to interfere with the sensing of neighboring cells by coupling through its bit line to neighboring ones. The noise can also couple through the common source line of the page to affect the accuracy of ongoing sensing of the cells in the page. Improved sense modules and method isolate the noise from the lockout sense module from affecting the other sense modules still active in sensing memory cell in the page. | 01-14-2010 |
| 20100148856 | Regulation of Recovery Rates in Charge Pumps - A method is presented of setting a frequency of a clock for a charge pump system including the clock and a charge pump. This includes setting an initial value for the frequency of the clock and, while operating the charge pump system using the clock running at the initial frequency value, determining the ramp rate of an output voltage for the charge pump during a recovery phase. The frequency of the clock is then adjusted so that the ramp rate of the output voltage for the charge pump during the recovery phase falls in a range not exceeding a predetermined maximum rate. A charge pump system is also described that includes a register having a settable value, where the charge pump clock frequency is responsive to the register value, and count and comparison circuitry is connectable to receive the pump's output voltage and the clock signal and determine from them the number of clock cycles the charge pump uses to recover from a reset value to a predetermined value. | 06-17-2010 |
