24316 results about "Voltage reference" patented technology

The present invention is a method, circuit and system for determining a reference voltage to be used in reading cells programmed to a given program state. Some embodiments of the present invention relate to a system, method and circuit for establishing a set of operating reference cells to be used in operating (e.g. reading) cells in a NVM block or array. As part of the present invention, at least a subset of cells of the NVM block or array may be read and the number of cells found at a given state associated with the array may be compared to one or more check sum values obtained during programming of the at least a subset of cells. A Read Verify threshold reference voltage associated with the given program state or associated with an adjacent state may be adjusted based on the result of the comparison.

Methods, devices and computer readable code for reading data from one or more flash memory cells, and for recovering from read errors are disclosed. In some embodiments, in the event of an error correction failure by an error detection and correction module, the flash memory cells are re-read at least once using one or more modified reference voltages, for example, until a successful error correction may be carried out. In some embodiments, after successful error correction a subsequent read request is handled without re-writing data (for example, reliable values of the read data) to the flash memory cells in the interim. In some embodiments, reference voltages associated with a reading where errors are corrected may be stored in memory, and retrieved when responding to a subsequent read request. In some embodiments, the modified reference voltages are predetermined reference voltages. Alternatively or additionally, these modified reference voltages may be determined as needed, for example, using randomly generated values or in accordance with information provided by the error detection and correction module. Methods, devices and computer readable code for reading data for situations where there is no error correction failure are also provided.

A charge control circuit for controlling a micro-electromechanical system (MEMS) device having variable capacitor formed by first conductive plate and a second conductive plate separated by a variable gap distance. The charge control circuit comprises a switch circuit configured to receive a reference voltage having a selected voltage level and configured to respond to an enable signal having a duration at least as long as an electrical time constant constant of the MEMS device, but shorter than a mechanical time constant of the MEMS device, to apply the selected voltage level across the first and second plates for the duration to thereby cause a stored charge having a desired magnitude to accumulate on the variable capacitor, wherein the variable gap distance is a function of the magnitude of the stored charge.

A light emitting diode (LED) lighting system includes a PFC and output voltage controller and a LED lighting power system. The controller advantageously operates from an auxiliary voltage less than a link voltage generated by the LED lighting power system. The common reference voltage allows all the components of lighting system to work together. A power factor correction switch and an LED drive current switch are coupled to the common reference node and have control node-to-common node, absolute voltage that allows the controller to control the conductivity of the switches. The LED lighting system can utilize feed forward control to concurrently modify power demand by the LED lighting power system and power demand of one or more LEDs. The LED lighting system can utilize a common current sense device to provide a common feedback signal to the controller representing current in at least two of the LEDs.

Cells of a flash memory are read by determining respective adaptive reference voltages for the cells and comparing the cells' threshold voltages to their respective reference voltages. The adaptive reference voltages are determined either from analog measurements of the threshold voltages of the cells' neighbors or from preliminary estimates of the cells' threshold voltages based on comparisons of the cells' threshold voltages with integral or fractional reference voltages common to all the cells. Cells of a flash memory also are read by comparing the cells' threshold voltages to integral reference voltages, comparing the threshold voltages of cells that share a common bit pattern to a fractional reference voltage, and adjusting the reference voltages in accordance with the comparisons.

A capacitive sensor includes a switching capacitor circuit, a comparator, and a charge dissipation circuit. The switching capacitor circuit reciprocally couples a sensing capacitor in series with a modulation capacitor during a first switching phase and discharges the sensing capacitor during a second switching phase. The comparator is coupled to compare a voltage potential on the modulation capacitor to a reference and to generate a modulation signal in response. The charge dissipation circuit is coupled to the modulation capacitor to selectively discharge the modulation capacitor in response to the modulation signal.

A touch surface device having improved sensitivity and dynamic range is disclosed. In one embodiment, the touch surface device includes a touch-sensitive panel having at least one sense node for providing an output signal indicative of a touch or no-touch condition on the panel; a compensation circuit, coupled to the at least one sense node, for generating a compensation signal that when summed with the output signal removes an undesired portion of the output signal so as to generated a compensated output signal; and an amplifier having an inverting input coupled to the output of the compensation circuit and a non-inverting input coupled to a known reference voltage.

A light-emitting element capable of emitting light having a preferred gradation level depending on display data. During a precharge period, a data driver applies a precharge voltage to a capacitor via a data line. After the application of the precharge voltage, a voltage converter reads a first reference voltage Vref(t1) and a second reference voltage Vref(t2) to generate a compensation voltage based on a difference between the respective reference voltages. Based on the compensation voltage, a voltage calculator compensates an original gradation level voltage Vorg having a value in accordance with display data generated by a gradation level voltage generator. The voltage calculator generates a compensated gradation level voltage Vpix corresponding to a variation amount of an element characteristic for a transistor Tr13 for driving light emission to apply the compensated gradation level voltage Vpix to a data line Ld.

An organic light-emitting diode display device includes a first switch element turned-on in response to a first scanning signal during a first period to supply a data to a first node, and then maintaining an off-state during a second period, a driving device adjusting a current through an organic light-emitting diode element in accordance with a voltage of the first node; a reference voltage source providing a reference voltage that is capable of turning-off the driving device, a second switch element maintaining an off-state during the first period, and turned-on during the second period to supply the reference voltage to the first node, and a storage capacitor maintaining the voltage at the first node.

Embodiments of the invention relate to a wireless physiological monitoring system. The system includes at least one wireless sensor and a monitoring device which are linked to one another of a wireless fashion for measuring physiological signals of a patient. The at least one wireless sensor is located on the patient and may comprise a wireless surface electrode assembly or a wireless needle assembly. The system may also comprise a wireless stimulator syncronized with the wireless sensor for performing certain diagnostic tests, such as nerve conduction velocity tests, for example. The wireless sensor preferably includes active, reference and common conductors. The common conductor can be used to measure the common mode voltage of the patient in the vicinity of the testing, and this voltage can then be subtracted from the measured active and reference voltages.

A storage subsystem implements a background process for selecting voltage reference values to use for reading data from a non-volatile memory array, such as an array of multi-level cell (MLC) flash memory. The process involves performing background read operations using specific sets of voltage reference values while monitoring the resulting bit error counts. The selected voltage reference values for specific pages or other blocks of the array are stored in a table. Read operations requested by a host system are executed using the corresponding voltage reference values specified by the table.

A plurality of memory cells are managed by obtaining values of one or more environmental parameters of the cells and adjusting values of one or more reference voltages of the cells accordingly. Alternatively, a statistic of at least some of the cells, relative to a single reference parameter that corresponds to a control parameter of the cells, is measured, and the value of the reference voltage is adjusted accordingly. Examples of environmental parameters include program-erase cycle count, data retention time and temperature. Examples of reference voltages include read reference voltages and program verify reference voltages. Examples of statistics include the fraction of cells whose threshold voltages exceed initial lower bounds or initial medians.

Many electrical sensing devices include an array of transducer elements for converting external stimuli to electrical indications. Novel technologies to realize improvements in low power consumption, low noise, and analog output path which occupies minimal die area while maintaining certain data rates are disclosed. A two stage pipeline architecture of the invention in the analog output path maintains fast pixel rates with minimal ADC (analog digital converter) arrangement. A novel power supply and the use of differential amplifiers in connection with a black signal level as a reference voltage are also described.

An LED lighting device of AC power-driven type having a comparatively simple constitution and a high power efficiency. The device compares a signal voltage (rectified voltage) obtained by rectifying an AC source with a predetermined reference voltage and controls ON/OFF of a driving current to each LED of an LED array in response to a comparison result. In this constitution, a large voltage of AC source enables lighting of more number of LEDs, while a small voltage thereof enables lighting of less number of LEDs, thus enhancing power efficiency of the LED lighting device.

A dual output buck-boost power converter operates with a single inductor to achieve high efficiency with automatic or inherent load balancing. Switches associated with the opposite polarity outputs are driven based on feedback signals, with one feedback signal being a reference voltage and another feedback signal being related to an opposite polarity output. The opposite polarity feedback signal is provided to a comparator with a reversed polarity to achieve a simple balanced control that maintains polarity outputs. The power converter delivers power to each output with each switching cycle and uses a single inductor to achieve high efficiency performance.

A driving circuit in an organic electroluminescent device includes a gate driver unit for sequentially outputting a control signal to select gate lines in a luminescent array unit and a current driver unit for supplying picture data to a data lines in the luminescent array unit corresponding to the gate lines selected by the gate driver unit and selectively driving organic electroluminescent devices of the selected line. The driving circuit includes a minimum gray level judgment unit for determining whether the picture data is of a predetermined minimum gray level; and a switching unit for receiving a control signal according to the determination made by the minimum gray level judgment unit and for selectively supplying a reference voltage or a reference current to the selectively driven organic electroluminescent devices.

An N-phase switching voltage regulator includes N current sensing elements which carry respective phase currents. The voltages present at the switch node sides of the sensing elements are summed and presented to an amplifier which also receives the regulator's output voltage, to produce an output which is proportional to the regulator's total output current I_out. The invention also provides a means for direct insertion of total inductor output current information into a regulator's voltage-mode control loop, to provide active voltage positioning (AVP) for the output voltage. A voltage based on total inductor output current is summed with the regulator's reference voltage; this sum and V_out are applied to the voltage control error amplifier, the output of which is processed to operate the regulator's switches. This enables the regulator's output to have a desired droop impedance and to provide AVP of V_out as a function of total filtered inductor output current I_out(fltr).

A device having a switch with a voltage applied across the switch. A current sensing circuit is connected to one terminal of the switch. The current sensing circuit receives power independently of the voltage applied across the switch. The power supply shares the other terminal of the switch with the current sensing circuit. The switch is adapted for opening and closing. When the switch closes, the current sensing circuit senses current through the switch and upon opening the switch the high voltage of the switch is blocked from the current sensing circuit. The sense current is caused to flow from the current sensing circuit to the other terminal when the switch is closed. The flow of the sense current produces a voltage which is compared differentially to another voltage referenced by the other terminal