Abstract: A method is for controlling reading of a dynamic random access memory (DRAM) including memory cells connected to a bit line of a memory plane of the DRAM and associated with a main reference cell connected to a reference bit line. The method may include reading and refreshing the contents of the memory cell and pre-charging the bit line, the reference bit line and the main reference cell for a subsequent read access. During reading and refreshing the memory cell, the main reference cell and a secondary reference cell connected to the bit line may be activated and, after having deactivated the two reference cells, they are pre-charged to a final pre-charge voltage. The final pre-charge voltage may be chosen to be less than or greater than (as a function of the NMOS or PMOS technology used, respectively) half the sum of a high-state storage voltage and a low-state storage voltage.

Abstract: The present invention relates to an amplifier having a fan-out which varies according to the time spent between an edge of a propagation signal and an edge of a logic input signal, the amplifier including several identical blocks, each block having an output stage connected between a data input and a data output, the data input and output being respectively connected to the data inputs and outputs of the other blocks; a delay element, the delay elements of all blocks being connected in series, the delay element of the first block receiving the synchronization signal; an edge detector, the input of which is connected to the input of the output stage; and means for inhibiting the propagation of the synchronization signal through the delay element when the signal generated by the edge detector of the preceding block is active and for activating the output stage and the edge detector when the signal generated by the delay element of the preceding block is active.

Abstract: A switching control method for level shifter includes a phase of de-selection of a high voltage value at an output terminal of the shifter using a selection signal. The de-selection phase may include starting the de-selection by bringing the selection signal to a low value; de-activating by way of the selection signal, the generation of a high-voltage signal being supplied to the shifter, and a reference voltage signal; computing the difference between an internal voltage signal of the shifter and the reference voltage signal; generating a control signal when the difference is found to be less than a threshold voltage value; and applying the selection signal to an input terminal of the shifter in the presence of the control signal.

Abstract: A glitch filter includes a storage element for storing a current state, which is the output of the filter. An output of the storage element is-connected to one input of a state comparator. Another input of the state comparator is connected to an input signal. A programmable clock delay is connected between the state comparator and the storage element. The programmable clock delay may provide a programmed duration independent of the technology used for implementation. The glitch filter is arranged such that the input signal is stored as the new current state in the storage element only if the input signal changes and then remains unchanged for the programmed duration.

Abstract: A process for making a DRAM-type cell includes growing layers of silicon germanium and layers of silicon, by epitaxy from a silicon substrate; superposing a first layer of N+ doped silicon and a second layer of P doped silicon; and forming a transistor on the silicon substrate. The method also includes etching a trench in the extension of the transistor to provide an access to the silicon germanium layers relative to the silicon layers over a pre-set depth to form lateral cavities, and forming a capacitor in the trench and in the lateral cavities.

Abstract: A receiver portion of a telephone includes a differential amplifier stage with a single output, an electroacoustic transducer connected between the output, via a capacitor and ground and a unit for controlling switching on/off, connected to the differential stage for the activation or deactivation thereof. To prevent annoying noises in the transducer upon switching on and off, the differential stage includes an operational amplifier having a first capacitor and a second capacitor in series with the inverting and the non-inverting input terminals. A third capacitor is connected between the inverting input and the output of the operational amplifier. A fourth capacitor is connected between the non-inverting input and a first reference-voltage terminal. A first switching capacitor is alternatively connectable between a second and a third reference-voltage terminal, or between the first input and the output of the operational amplifier.

Abstract: A clock signal filtering circuit includes a bistable flip-flop and a controller for controlling state changes of the flip-flop. A first activation circuit activates the controller by edges of non-filtered clock signal pulses when their duration exceeds a first threshold. The first threshold is equal to a half-period corresponding to an upper frequency limit of the clock signal. A second activation circuit activates the controller by edges of filtered clock signal pulses delayed by an amount equal to a half period corresponding to a lower frequency limit of the clock signal. The clock filtering circuit transmits a filtered clock signal at a frequency within a specification interval, and at a duty cycle equal to 0.5 for a variety of different circumstances.

Abstract: A memory device having redundancy is disclosed. The memory device includes an array of memory cells organized into rows and columns of memory cells, each row of memory cells including a plurality of addressable memory cells and redundant memory cells, the array of memory cells including row lines and column lines, each row line being coupled to memory cells in a distinct row of memory cells, each column line being coupled to memory cells in a distinct column of memory cells, and column input/output lines. The memory device further includes a redundancy circuitry for selectively coupling column lines to column input/output lines of the array of memory cells and selectively decoupling at least one column line from the column input/output lines, based upon an address value received by the memory device during a memory access operation.

Abstract: A reading circuit is provided for reading a memory cell. The reading circuit includes a reference current source, a memory cell biased between its first and second terminals at a predetermined voltage, comparison means for comparing a current flowing in the memory cell with the reference current, and a control gate voltage source coupled to a third terminal of the memory cell. The control gate voltage source includes a virgin memory cell that is biased between two terminals with a voltage of equal value to the biasing voltage of the memory cell. The control gate voltage source produces a control gate voltage at another terminal of the virgin memory cell. In one preferred embodiment, the memory cell and the virgin memory cell are EEPROM cells.

Abstract: A current control method controls current for drive systems of multi-phase brushless motors, in particular at phase switching, wherein the motor coils coupled to a common node are driven by applying a respective drive voltage to the free end of each coil via corresponding power stages. The method comprises switching the current flow from one phase to the next in the direction of rotation of the motor at the phase switch, thereby forcing the unaffected one of said coils by the phase switch into a state of high impedance. Advantageously, the decreasing rate of the current in the coil unaffected by the phase switch can be twice as high as the decreasing rate of the current in the phase being switched from.

Abstract: A sense amplifier circuit and method are disclosed for nonvolatile memory devices, such as flash memory devices. The sense amplifier circuit includes a current source that is configurable to source any of at least two nonzero current levels in the sense amplifier circuit. The sense amplifier circuit is controlled by control circuitry in the nonvolatile memory device so that each sense amplifier circuit sources a first current level during the precharge cycle of a memory read operation, and a second current level, greater than the first current level, during the memory cell sense operation. In this way, the sense amplifier circuit consumes less power during the memory read operation without an appreciable loss in performance.

Abstract: The equivalent computational precision in an associative memory is increased by determining the difference between the bit precision that is required in order to represent a given number in the memory and the bit precision that can be represented in a memory element of the memory, which is dictated by the inherent characteristics of the memory; determining, on the basis of the difference, the number of memory elements of the memory required in order to represent the given number with the required bit precision; and dividing the given number over the number of memory element of the memory, determining a base value to be loaded into the number of memory element and a remainder which indicates a subset of the number of memory element of the memory over which the remainder is to be divided.

Abstract: The invention relates to a method of adjusting the erase/program voltage in semiconductor non-volatile memories. The memories are formed of at least one matrix of memory cells having a floating gate, a control gate, and drain and source terminals, and are organized by the byte in rows and columns, each byte comprising a group of cells having respective control gates connected in parallel with one another to a common control line through a selection element of the byte switch type, and each cell being connected to a respective control column through a selection element of the bit switch type. Advantageously, a double adjustment is provided for the program voltage of the memory cells, whereby the program voltage during the erasing phase can be higher in modulo than the program voltage during the writing phase.

Abstract: A method of fabricating a MOS transistor with a controllable and modulatable conduction path through a dielectric gate oxide is disclosed, wherein the transistor structure comprises a dielectric oxide layer formed between two silicon plates, and wherein the silicon plates overhang the oxide layer all around to define an undercut having a substantially rectangular cross-sectional shape. The method comprises the steps of: chemically altering the surfaces of the silicon plates to have different functional groups provided in the undercut from those in the remainder of the surfaces; and selectively reacting the functional groups provided in the undercut with an organic molecule having a reversibly reducible center and a molecular length substantially equal to the width of the undercut, thereby to establish a covalent bond to each end of the organic molecule.

Abstract: Described herein is an output buffer including an output stage formed by a pull-up transistor and a pull-down transistor, which are connected in series between a supply line set at a supply potential and a ground line set at a ground potential, with an intermediate node connected to the output of the output buffer. The output buffer further includes a unidirectional decoupling stage arranged between the output of the output buffer and the pull-up transistor for decoupling the output from the supply line during the switching transients of the output buffer in such a way as to prevent the switching noise present on the latter from being transferred onto the output of the output buffer.

Abstract: Estimating the speed of movement of a mobile terminal of a wireless communication system communicating with a base station includes calculating a normalized auto-covariance of the instantaneous power of the signal received by the mobile terminal or by the base station.

Abstract: A data-storage disk includes a disk sector for storing data and a servo wedge located at the beginning of the sector. The servo wedge indentifies the sector in conjunction with both an initial positioning of a read-write head and a data read or write operation. By using a servo wedge to provide both an initial head position on disk spin up and a head position during a read or write operation, one can increase a disk's data-storage capacity by reducing the number of, or altogether eliminating, spin-up wedges.

Abstract: A new synchronous Partial Response Maximum Likelihood (PRML) servo is provided for a high track-per-inch disk-drive system. To increase the data capacity in hard disk drives (HDD), one can shorten the servo format and/or increase the track density. The new servo system has circuits that allow a high-performance and accurate system for positioning the read-write heads. The major circuits include burst demodulation, Viterbi detection, timing synchronization, and spin-up search. A highly linear discrete-fourier-transform (DFT) burst-demodulation circuit can demodulate high-density and low-signal-to-noise-ratio (SNR) position bursts. The Viterbi detection circuit includes a sync-mark detector and a Viterbi detector that are matched to at least two sets of Gray code ( e.g., ¼ rate and {fraction (4/12)} rate) and pruned accordingly. The timing synchronization circuit includes phase restart and interpolating timing recovery (ITR) circuits to implement a fully digital timing recovery.

Abstract: A GaAs/Ge on Si CMOS integrated circuit is formed to improve transistor switching (propagation) delay by taking advantage of the high electron mobility for GaAs in the N-channel device and the high hole mobility for Ge in the P-channel device. A semi-insulating (undoped) layer of GaAs is formed over a silicon base to provide a buffer layer eliminating the possibility of latch-up. GaAs and Ge wells are then formed over the semi-insulating GaAs layer, electrically isolated by standard thermal oxide and/or flowable oxide (HSQ). N-channel MOS devices and P-channel MOS devices are formed in the GaAs and Ge wells, respectively, and interconnected to form the integrated circuit. Gate electrodes for devices in both wells may be polysilicon, while the gate oxide is preferably gallium oxide for the N-channel devices and silicon dioxide for the P-channel devices. Minimum device feature sizes may be 0.5 &mgr;m to avoid hot carrier degradation while still achieving performance increases over 0.

Abstract: A modular semiconductor power device has a conductive member consisting of an alumina plate to which copper layers are soldered on opposite sides. A chip is soldered to one of these layers and the other of these layers is soldered in turn to a metal heat sink. The chip is connected to respective copper strips which, in turn, are soldered to thermal strips originally forming part of a frame so that, after the device is encapsulated in a synthetic resin, the connecting members of the frame can be cut away to leave free ends of the latter strips exposed.