摘要:
A memory circuit arrangement for sensing current in a target cell during a read operation is disclosed. According to one exemplary embodiment, the memory circuit arrangement comprises the target cell and a first neighboring cell adjacent to the target cell. The first target cell has a first bit line connected to ground; the target cell also has a second bit line connected to a sensing circuit. The first neighboring cell shares the second bit line with the target cell; the first neighboring cell also has a third bit line connected to the sensing circuit during the read operation. The memory circuit arrangement results in increased error margins in a fast and accurate manner during the read operation of the target cell.
摘要:
A system is disclosed for generating a regulated negative charge pump voltage for flash memory operations, wherein a capacitive voltage divider circuit comprising one or more MOS capacitors is configured to respond to the regulated output voltage of a negative charge pump circuit and an output circuit source loading and generate a voltage divider output signal associated therewith. The system also includes an initialization circuit which is configured to precharge the capacitors of the MOS capacitor voltage divider with a reference voltage. The system further includes a bias circuit operable to generate a bias voltage which is used in association with the MOS capacitors to insure they operate above a bias voltage which will maintain a minimum target capacitance within the voltage divider, resulting in a stable target regulation voltage. The negative regulator also includes an output circuit operable to source the negative charge pump output voltage to a supply voltage, and a negative regulator control circuit operably coupled to the initialization circuit and the capacitive voltage divider circuit, and operable to receive the bias circuit voltage and the associated MOS capacitor voltage divider circuit output, and operable to receive a negative charge pump output voltage and regulate an output circuit source loading via the supply voltage to produce a feedback to the negative charge pump circuit based on the target voltage value established by the MOS capacitor voltage divider, thereby creating a reduced area negative regulator used in conjunction with a negative charge pump circuit, which maintains a low power and simple regulator design, to produce a regulated charge pump output which may be used as a pumped voltage for various mode operations of memory cells.
摘要:
The present invention relates to flash memory systems and methods to determine the threshold voltage of core cells. In one exemplary system, there is provided a method of characterizing the high end of the threshold voltage distribution of an array of programmed cells. In accordance with the invention, an exemplary system and method are presented to apply a varying characterization signal operably through a high breakdown voltage periphery donut transistor and wordline drive transistors, which are driven into saturation by a boosted gate voltage which is higher than the applied varying characterization signal, in a manner which provides for the accurate determination of the VT of the core cells, through the comparison of the conduction in a reference cell to that of the conduction in a core cell produced by a varying characterization signal applied to the core cell gate.
摘要:
Control circuitry and a method for generating an accurate boosted wordline voltage for selected memory core cells in a semiconductor memory device during a Read mode of operation is provided. Memory core transistors are provided which have their conduction path being coupled between a power supply voltage and a ground potential. Differential amplifier circuitry is responsive to a boost signal and a reference voltage for generating a select wordline voltage. The select wordline voltage is decreased when the wordline voltage is higher than a desired voltage and is increased when the wordline voltage is lower than the desired voltage. The control gates of the memory core transistors are responsive to the select wordline voltage.
摘要:
The invention comprises a means for generating energy while walking or running for storage in a rechargeable battery. One embodiment uses lever arm movement in the heel of a shoe resulting from normal walking or running to generate energy from a built-in generator. The linear or rotational motion of the lever arm engages the circular gear assembly and turns the generator/motor/turbine, thus generating power. The second embodiment uses fluid reservoirs embedded in the shoes. Pressure changes resulting from normal walking or running moves the fluid through a narrow channel connecting two reservoirs, thus generating power by rotating a flywheel and an attached motor/generator/turbine in the middle of the channel. Secondary (rechargeable) batteries are incorporated into the invention either in an integrated form or as an add-on design. Additional features include a digital diagnostic data output, which would serves as a “fuel gauge” for the secondary batteries, and a smart charging circuit that efficiently controls battery charging from a generator output that varies with step rate and force.
摘要:
A microprocessor-based charge control architecture which provides individual battery cell charge control in order to insure an equality of charge among all cells in a rechargeable battery cell array during a single charge cycle. The array is arranged in parallel strings with an identical number of cells in series in each string. The microprocessor controls the amount of charge current in each battery cell via a shunt element for each battery cell, and adjusts the shunt element to bypass a portion of the string current for each battery cell. The invention also permits charge control algorithms to be conveniently updated, provides individual cell coulometry, and autonomously monitors and corrects conditions which can result in battery failure. Any type of rechargeable battery cell and array size can be accommodated. The array size can be set to accommodate the specific voltage and load current requirements of each application.
摘要:
A method is provided for biasing a NAND array EEPROM during programming to allow the array to be scaled down further before reach punchthrough. The sources of the ground-select transistors of the NAND array are biased at V.sub.cc instead of ground to reduce the voltage drop across the source and drain of the ground-select transistors. As a result, the channel length of the ground-select transistors can be further shortened before punchthrough is obtained, resulting in a higher density EEPROM.
摘要:
A system is described for generating a charge pump voltage for flash memory operations, wherein a supply voltage detection circuit (e.g., analog to digital converter, digital thermometer) is configured to detect a supply voltage value and generate one or more supply voltage level detection signals associated therewith. The system further includes a charge pump circuit comprising one or more stages operable to receive a supply voltage and generate the charge pump output voltage having a value greater than the supply voltage, and a charge pump compensation circuit operably coupled to the supply voltage detection circuit and the charge pump circuit. The charge pump compensation circuit is operable to receive the one or more output signals from the supply voltage detection circuit and modulate a capacitive loading associated with the charge pump circuit based on the one or more output signals, thereby creating an improved low power charge pump which uses a modulated pumping capacitance to compensate for fluctuations of the input power supply (for example, VCC), to produce a slow ripple and low noise output which may be used as a pumped voltage for various mode operations (e.g., erase, program modes) of memory cells.
摘要:
Control circuitry and a method for generating an accurate drain voltage for selected memory core cells in a semiconductor memory device during a Read mode of operation is provided. Select gate transistors are provided which have their conduction path being coupled between a power supply voltage and a drain of one of the selected memory core cells. A differential amplifier circuit is responsive to a bitline voltage corresponding to a drain voltage of the selected memory core cells and a reference voltage for generating a select gate voltage. The select gate voltage is decreased when the bitline voltage is higher than a target voltage and is increased when the bitline voltage is lower than the target voltage. A source follower circuit is responsive to the select gate voltage for generating the bitline voltage which is maintained at the target voltage. The control gates of the select gate transistors are connected to receive the select gate voltage for maintaining the voltage at the drain of the selected memory core cells to be approximately constant.
摘要:
An apparatus and a method for reducing capacitive loading in a Flash memory X-decoder so as to accurately control the voltages as selected wordlines and block select lines are provided. A decoding structure separately applies a first boosted voltage to the wordline N-well region and a second boosted voltage to the selected wordline so as to reduce capacitive loading on the selected wordline due to heavy capacitive loading associated with the wordline N-well region. The decoding structure further applies a third boosted voltage to the select gate N-well region and a fourth boosted voltage to the block select line so as to reduce capacitive loading on the block select line due to heavy capacitive loading associated with the select gate N-well region. As a consequence, an accurate voltage can be created quickly at the selected wordline since its capacitive loading path is very small.