Abstract: A memory includes a plurality of memory cells, a sense amplifier coupled to at least one of the plurality of memory cells, a temperature dependent current generator comprising a plurality of selectable temperature dependent current sources for generating a temperature dependent current, a temperature independent current generator comprising a plurality of selectable temperature independent current sources for generating a temperature independent current, and a summer coupled to the temperature dependent current generator and the temperature independent current generator for combining the temperature dependent current and the temperature independent current to generate a reference current for use by the sense amplifier. A temperature coefficient of the reference current is approximately a same as a temperature coefficient of a memory cell current of at least one of the plurality of memory cells.

Abstract: An integrated circuit (10) comprises a plurality of non-volatile memory cells (14) and a charge distribution ramp rate control circuit (11). Each memory cell of the array (12) includes a charge storage region and a plurality of terminals. The charge distribution ramp rate control circuit includes a capacitor (62,116,144) having a first plate electrode coupled to at least one terminal of the plurality of terminals, and a second plate electrode. The charge distribution ramp rate control circuit further includes a bandgap generated current source (58,106,136) for providing a reference current to determine a ramp rate of a voltage at the at least one terminal.

Abstract: A program voltage is applied to the drain electrode of a floating gate transistor to program the floating gate transistor. Concurrent with the application of the program voltage, a current based on the voltage at the source electrode of the floating gate transistor is compared with a threshold current to verify the programming of the floating gate transistor. When the bit cell current falls below the threshold current, the floating gate transistor is considered to be sufficiently programmed and the next floating gate transistor to be programmed is selected. Further, the program voltage supply emulates the selection circuitry used to select between the bit cells so as to model the voltage drop caused by the selection circuitry between the program voltage supply and the drain electrode of the floating gate transistor being programmed. The program voltage supply adjusts the output program voltage based on the modeled voltage drop.

Abstract: A memory comprises a sense amplifier for sensing a logic state of a selected bitline. The sense amplifier includes a first precharge circuit, a current-to-voltage converter, a latch circuit, and a second precharge circuit. The first precharge circuit is for precharging a selected bitline to a first predetermined voltage in response to a first precharge signal. The current-to-voltage converter has a current input coupled to the selected bitline, and a voltage output. A latch circuit has a storage node coupled to the voltage output of the current-to-voltage converter. The second precharge circuit is for precharging the storage node of the latch circuit to a second predetermined voltage in response to a second precharge signal.

Abstract: A charge pump system including a clock circuit and a charge pump circuit is provided. The clock circuit provides a first clock with a frequency based on a memory block select signal indicative of load capacitance of a charge node. The charge pump circuit receives the first clock and charges the charge node at a rate based on the frequency of the first clock and the load capacitance of the charge node. The memory block select signal indicates which of the memory blocks are coupled to the charge node and thus indicates the load capacitance of the charge node. The frequency of the first clock is adjusted based on the load capacitance of the selected block so that the slew rate of the charge node is about the same. Thus, the slew rate of the voltage ramp on the charge node is about the same regardless of the load capacitance.

Abstract: A memory includes a plurality of memory cells, a sense amplifier coupled to at least one of the plurality of memory cells, a temperature dependent current generator comprising a plurality of selectable temperature dependent current sources for generating a temperature dependent current, a temperature independent current generator comprising a plurality of selectable temperature independent current sources for generating a temperature independent current, and a summer coupled to the temperature dependent current generator and the temperature independent current generator for combining the temperature dependent current and the temperature independent current to generate a reference current for use by the sense amplifier. A temperature coefficient of the reference current is approximately a same as a temperature coefficient of a memory cell current of at least one of the plurality of memory cells.

Abstract: An electronic data storage system uses current comparison to generate a voltage bias. In at least one embodiment, a voltage bias generator, that includes a current differential amplifier, generates a current that charges a load to a predetermined voltage bias level. The current comparison results in the comparison between two currents, Iref and Isaref. The current Isaref can be generated using components that match components in the load and memory circuits in the system. In one embodiment, multiple sense amplifiers represent the load. By using matched components, as physical characteristics of the load and memory circuits change, the current Isaref also changes. Thus, the voltage bias changes to match the changing characteristics of the load and memory circuits. The voltage bias generator can include a current booster that decreases the initial charging time of a reactive load.

Abstract: A program voltage is applied to the drain electrode of a floating gate transistor to program the floating gate transistor. Concurrent with the application of the program voltage, a current based on the voltage at the source electrode of the floating gate transistor is compared with a threshold current to verify the programming of the floating gate transistor. When the bit cell current falls below the threshold current, the floating gate transistor is considered to be sufficiently programmed and the next floating gate transistor to be programmed is selected. Further, the program voltage supply emulates the selection circuitry used to select between the bit cells so as to model the voltage drop caused by the selection circuitry between the program voltage supply and the drain electrode of the floating gate transistor being programmed. The program voltage supply adjusts the output program voltage based on the modeled voltage drop.

Abstract: An adjustable voltage supply (310) may have a plurality of levels of adjustment, such as a coarse select circuit (471) and a fine select circuit (473), to generate an adjustable voltage (e.g. Vout 364 of FIGS. 3 and 4) with fine resolution across a wide voltage range. In one embodiment, the adjustable voltage may be used as an adjustable read voltage to measure the threshold voltages of bitcells in a memory array (300). From the distribution of these threshold voltages, it is possible to determine the marginality of the bitcells with regard to the voltage which is required to read the bitcells. In one embodiment, the adjustable voltage supply (310) may also be used to provide an adjustable voltage to one or more integrated circuit pwells and/or nwells in order to apply electrical stress. An adjustable voltage supply (310) may be used in any desired context, not just memories.

Abstract: A floating voltage source circuit that provides a floating voltage. The floating voltage source circuit includes a feedback current path and a floating voltage current path, where the floating voltage provided by the floating voltage current path is dependent upon a current of the feedback current path. The current through the feedback current path is controlled by the reference voltage.

Abstract: A charge pump system has a charge pump for receiving a clock signal and provides an output signal of increased voltage magnitude in response to an enable signal. A plurality of comparators is coupled to the charge pump for detecting when the output signal is greater than a reference value. Each of the plurality of comparators is controlled by a respective different control signal derived from the clock signal and has differing phases. Detection circuitry is coupled to the plurality of comparators for providing the enable signal in response to detecting first leading rising edges and first leading falling edges of signals provided by the plurality of comparators. The interleaving operation of the comparators results in tighter regulation of the charge pump which reduces voltage ripple without significantly increasing capacitive load on the charge pump.

Abstract: An integrated circuit includes a memory (10). The memory (10) includes an array (12) of non-volatile memory cells. Each memory cell (14) of the array (12) includes a plurality of terminals comprising: a control gate, a charge storage region, a source, a drain, a well terminal, and a deep well terminal. Following an erase operation of the array (12), the erase voltages are discharged from each of the memory cells. A discharge rate control circuit (11) controls the discharging of terminals of the memory cell. The discharge rate control circuit (11) includes, for example, a plurality of parallel-connected transistors (112) coupled between the array (12) of non-volatile memory cells and a power supply terminal.

Abstract: An integrated circuit includes a memory (10). The memory (10) includes an array (12) of non-volatile memory cells. Each memory cell (14) of the array (12) includes a plurality of terminals comprising: a control gate, a charge storage region, a source, a drain, a well terminal, and a deep well terminal. Following an erase operation of the array (12), the erase voltages are discharged from each of the memory cells. A discharge rate control circuit (11) controls the discharging of terminals of the memory cell. The discharge rate control circuit (11) includes a reference current generator (34) for providing a reference current. A first current mirror (46) is coupled to the reference current generator (34) and provides a first predetermined discharge current for discharging the control gate, drain, and source. A second current mirror (36) is coupled to the reference current generator (34) and provides a second predetermined discharge current for discharging the well terminals after the erase operation.

Abstract: Each cell of a memory is programmed by first using a source bias that is typically effective for programming the cells. If a cell is not successfully programmed in the first attempt, that is typically because a number of cells on the same column as that of the cell that did not successfully program have a relatively low threshold voltage, a low enough threshold voltage that these memory cells are biased, even with grounded gates, to be conductive. The vast majority of the cells do not have this problem, but it is common for there to be a few memory cells that do have this low threshold voltage characteristic. To overcome this, a different source bias is applied during subsequent programming attempts. Thus, the vast majority of the cells are programmed at the faster programming condition, and only the few that need it are programmed using the slower approach.

Abstract: A memory array of one-transistor (1T) SONOS bit cells in a common-source architecture is used in conjunction with a reverse read technique to reduce the effect of read disturb. Bit line voltage in the array, during read operation, is constrained to a Vt or less, relative to the control gate, so that read disturb is limited. When information is programmed into a bit cell in the array, the bit line is used as a drain, which has the effect of concentrating charge toward the bitline end of the SONOS transistor. When information is read from a bit cell in the array, the bit line of the selected bit cell is used as a source, instead of a drain. That reversal gives a larger Vt contrast between a 0 and a 1 than a forward read, for a given amount of stored charge.

Abstract: Each cell of a memory is programmed by first using a source bias that is typically effective for programming the cells. If a cell is not successfully programmed in the first attempt, that is typically because a number of cells on the same column as that of the cell that did not successfully program have a relatively low threshold voltage, a low enough threshold voltage that these memory cells are biased, even with grounded gates, to be conductive. The vast majority of the cells do not have this problem, but it is common for there to be a few memory cells that do have this low threshold voltage characteristic. To overcome this, a different source bias is applied during subsequent programming attempts. Thus, the vast majority of the cells are programmed at the faster programming condition, and only the few that need it are programmed using the slower approach.

Abstract: A memory device is disclosed having a column select transistor gate that is controlled by tri-statable control logic. The tri-statable control logic operates to allow the gate of the column select transistor to float during sensing of the bit cell. The column select transistor acts as a floating gate amplifier, i.e. a common gate amplifier having a gate that floats during the sensing period. In addition, the column select transistor can operate to facilitate decoding of the memory and to allow precharge of a bit line of a memory cell. Further, avoidance of a static power drain is made possible by the fact that the gate is floating during the sensing period.

Abstract: A memory array of one-transistor (1T) SONOS bit cells in a common-source architecture is used in conjunction with a reverse read technique to reduce the effect of read disturb. Bit line voltage in the array, during read operation, is constrained to a Vt or less, relative to the control gate, so that read disturb is limited. When information is programmed into a bit cell in the array, the bit line is used as a drain, which has the effect of concentrating charge toward the bitline end of the SONOS transistor. When information is read from a bit cell in the array, the bit line of the selected bit cell is used as a source, instead of a drain. That reversal gives a larger Vt contrast between a 0 and a 1 than a forward read, for a given amount of stored charge.

Abstract: A memory device is disclosed having a column select transistor gate that is controlled by tri-statable control logic. The tri-statable control logic operates to allow the gate of the column select transistor to float during sensing of the bit cell. The column select transistor acts as a floating gate amplifier, i.e. a common gate amplifier having a gate that floats during the sensing period. In addition, the column select transistor can operate to facilitate decoding of the memory and to allow precharge of a bit line of a memory cell. Further, avoidance of a static power drain is made possible by the fact that the gate is floating during the sensing period.