Patents Assigned to STMicroelectronics
  • Patent number: 6130165
    Abstract: Self-aligned etching process for providing a plurality of mutually parallel word lines in a first conducting layer deposited over a planarized architecture obtained starting from a semiconductor substrate on which is provided a plurality of active elements extending along separate parallel lines e.g., memory cell bit lines and comprising gate regions made up of a first conducting layer, an intermediate dielectric layer and a second conducting layer with said regions being insulated from each other by insulation regions to form said architecture with said word lines being defined photolithographically by protective strips implemented by means of: a vertical profile etching for complete removal from the unprotected areas of the first conducting layer of the second conducting layer and of the intermediate dielectric layer respectively, and a following isotropic etching of the first conducting layer.
    Type: Grant
    Filed: December 23, 1997
    Date of Patent: October 10, 2000
    Assignee: STMicroelectronics, S.r.l.
    Inventors: Emilio Camerlenghi, Elio Colabella, Luca Pividori, Adriana Rebora
  • Patent number: 6130844
    Abstract: A boosted voltage driving circuit includes an inverter circuit with positive feedback and a selective breaking circuit. The selective breaking circuit disconnects the positive feedback from the output load during an operation phase of the boosted voltage driving circuit in order to reduce energy consumption. In a preferred embodiment, the boosted voltage driving circuit is the final stage of a decoder circuit for selecting and deselecting a line or column of a memory array, and the positive feedback is disconnected during a deselection phase in which the line or column is deselected. The present invention also provides a boosted voltage driving circuit that includes first, second, and third transistors and a selective breaking circuit. The first transistor is connected between a supply voltage and an output node, the second transistor is connected between the output node and ground, and the third transistor is connected between the supply voltage and the gate of the first transistor.
    Type: Grant
    Filed: February 26, 1999
    Date of Patent: October 10, 2000
    Assignee: STMicroelectronics S.r.l.
    Inventors: Tommaso Zerilli, Maurizio Gaibotti
  • Patent number: 6130527
    Abstract: A voltage regulator providing smooth variation of an absorbed current having a first capacitor parallel-connected to a load, which is in turn connected to a supply voltage; a transconductor coupled between the supply voltage and the load and whose output voltage supplies the load; a differential amplifier coupled between the output of the transconductor and the supply voltage, and further coupled to the input of the transconductor, a second capacitor coupled between the supply voltage and the input of the transconductor; and a pair of diodes coupled between the output of the transconductor and the first capacitor and configured to introduce a zero in the transfer function of the voltage regulator that is suitable to compensate for a pole generated by the first capacitor.
    Type: Grant
    Filed: August 20, 1999
    Date of Patent: October 10, 2000
    Assignee: STMicroelectronics S.r.l.
    Inventors: Gregorio Bontempo, Francesco Pulvirenti
  • Patent number: 6131138
    Abstract: The present invention provides an improved disc drive. In one embodiment of the present invention a disc drive capable of spinning a disc, which contains more than one type of data is disclosed. A first type of data is associated with a first speed, and a second type of data is associated with a second speed that is faster than the first speed. The disc drive includes a drive mechanism, which may spin the compact disc at the first and second speeds and retrieve data from the compact disc at either speed. The disc drive also includes an elastic buffer, which is in communication with the drive mechanism. The buffer receives data from the drive mechanism at a variable input data rate and outputs data at a variable output data rate. Whereby when the drive mechanism spins the compact disc at the second speed the buffer may receive the first type of data without causing the drive mechanism to slow down to the first speed, and the buffer may output the first type of data at the variable output data rate.
    Type: Grant
    Filed: August 18, 1997
    Date of Patent: October 10, 2000
    Assignee: STMicroelectronics N.V.
    Inventors: John S. Packer, Steven D. Wilson
  • Patent number: 6130572
    Abstract: A negative charge pump circuit comprises a plurality of charge pump stages connected in series to each other. Each stage has a stage input terminal and a stage output terminal. A first stage has the stage input terminal connected to a reference voltage, a final stage has the stage output terminal operatively connected to an output terminal of the charge pump at which a negative voltage is developed; intermediate stages have the respective stage input terminal connected to the stage output terminal of a preceding stage and the respective stage output terminal connected to the stage input terminal of a following stage.
    Type: Grant
    Filed: January 23, 1998
    Date of Patent: October 10, 2000
    Assignee: STMicroelectronics S.r.l.
    Inventors: Andrea Ghilardelli, Jacopo Mulatti, Maurizio Branchetti
  • Patent number: 6128243
    Abstract: A method of operating a memory cell includes detecting a first power supply anomaly or condition. When the first power supply condition occurs, memory cell access to bit lines is disabled, a series of shadow memory access FETs within the memory cells are enabled and data from the memory cells are coupled to memory FETs within the memory cells to store data corresponding to the data from the memory cells in the memory FETs. The memory FETs include nanocrystals of semiconductor material in gate dielectrics of the FETs. Electrons are stored in the nanocrystals of semiconductor material to represent the data stored in the memory cell. When a second power supply condition is detected, the data stored in the memory FETs are written back to the memory cells.
    Type: Grant
    Filed: December 3, 1999
    Date of Patent: October 3, 2000
    Assignee: STMicroelectronics, Inc.
    Inventors: Tsiu C. Chan, Jim Brady, Pervez Hassan Sagarwala
  • Patent number: 6128219
    Abstract: A test structure is formed by an array of memory cells connected in parallel and including each a memory transistor and a select transistor connected in series. The gate terminals of the select transistors of all memory cells are biased to a value next to the threshold voltage of the select transistors. Therefore, in each memory cell, the drain current is limited by the memory transistor for control gate voltages below the threshold voltage of the memory transistor, and by the select transistor at higher voltages; for high control gate voltages, the drain current is clamped to a constant maximum value. Since the clamping effect of the select transistors acts on each memory cell, the total maximum current of the test structure may be held below a value causing a limitation in the current generated by the entire array because of the resistance in series to the output of the test structure.
    Type: Grant
    Filed: October 27, 1999
    Date of Patent: October 3, 2000
    Assignee: STMicroelectronics, S.r.l.
    Inventors: Federico Pio, Enrico Gomiero, Alberto Modelli, Paola Paruzzi
  • Patent number: 6127873
    Abstract: A feedforward circuit structure with programmable zeros for synthesizing continuous-time filters, delay lines, and the like is described. The circuit comprises a first cell and a second cell which are cascade-connected. Each one of the first and second cells comprises first and second pairs of bipolar transistors. The emitter terminals of the first pair of transistors are connected to a first current source, and the emitter terminals of the second pair of transistors are connected to a second current source. A first high-impedance element is connected between the first and second pairs of transistors, and a second high-impedance element is connected at an output of the second pair of transistors. A fifth transistor is connected between the collector terminal of a first transistor of the first pair of transistors and the collector terminal of a second transistor of the second pair of transistors.
    Type: Grant
    Filed: December 23, 1998
    Date of Patent: October 3, 2000
    Assignee: STMicroelectronics S.r.l.
    Inventors: Salvatore Portaluri, Valerio Pisati
  • Patent number: 6128228
    Abstract: An analog read circuit includes an output transistor connected to a memory cell to be read, and an operational amplifier having a non-inverting input connected to the drain terminal of the memory cell, an inverting input connected to a reference terminal, and an output, forming the output of the reading circuit and connected to the gate terminal of the output transistor. Bias transistors maintain the memory cell and the output transistor in the linear region, and the operational amplifier and the output transistor form a negative feedback loop so that the output voltage V.sub.O of the read circuit is linerly dependent upon the threshold voltage the memory cell. The reading circuit has high precision and high reading speed.
    Type: Grant
    Filed: November 12, 1999
    Date of Patent: October 3, 2000
    Assignee: STMicroelectronics S.r.l.
    Inventors: Marco Pasotti, Roberto Canegallo, Giovanni Guaitini, Pier Luigi Rolandi
  • Patent number: 6128222
    Abstract: A Flash-EPROM type memory cell with a short read time and a "very low supply voltage." The memory cell has the additional advantage of using less power, therefore generating less heat and allowing a denser integrated circuit. The memory cell comprises a floating-gate transistor whose source is coupled to the drain of a selection transistor. The floating-gate transistor is in a depleted state when the memory cell is "erased." The read voltage applied to the control gate of the floating-gate transistor is substantially equal to a general supply voltage which is in the range of 1.5 volts. The gate of the selection transistor receives a bias voltage at least equal to its conduction threshold. The gate of the selection transistor can also receive a bias voltage higher than the read voltage, which will speed up the read time further. A Flash-EPROM incorporating this memory cell is also provided.
    Type: Grant
    Filed: October 15, 1998
    Date of Patent: October 3, 2000
    Assignee: STMicroelectronics S.A.
    Inventor: Christophe Moreaux
  • Patent number: 6127224
    Abstract: A non-volatile memory cell and a manufacturing process therefor are discussed. The cell is integrated in a semiconductor substrate and includes a floating gate transistor having a first source region, first drain region, and gate region projecting over the substrate between the first source and drain regions. The cell also includes a selection transistor having a second source region, second drain region, and respective gate region, projecting over the substrate between the second source and drain regions. The first and second regions are lightly doped and the cell comprises mask elements.
    Type: Grant
    Filed: December 29, 1998
    Date of Patent: October 3, 2000
    Assignee: STMicroelectronics, S.r.l.
    Inventor: Federico Pio
  • Patent number: 6128225
    Abstract: The read circuit has an array branch connected to an array cell, and a reference branch connected to a reference cell; the array branch presents an array load transistor interposed between a supply line and the array cell, and the reference branch presents a reference load transistor interposed between the supply line and the reference cell; and the array and reference load transistors form a current mirror wherein the array load transistor is diode-connected and presents a first predetermined channel width/length ratio, and the reference load transistor presents a second predetermined channel width/length ratio N times greater than the first ratio, so that the current flowing in the array cell is supplied, amplified, to the reference branch.
    Type: Grant
    Filed: June 18, 1997
    Date of Patent: October 3, 2000
    Assignee: STMicroelectronics S.r.l.
    Inventors: Giovanni Campardo, Rino Micheloni, Stefano Commodaro
  • Patent number: 6127868
    Abstract: The a timer circuit and oscillator are disclosed. The timer circuit is similar in functionality to a '555 timer circuit but uses few transistors. The timer circuit has two differential pairs of transistors, three current mirrors, two selectable current sources, and one inverter. The two differential pairs of transistors, three current mirrors, two selectable current sources, and one inverter are arranged to receive an IN+ voltage, an IN voltage, and a IN- voltage. From these inputs a Q and a Q(bar) output is generated. This timing circuit can be used to generate an oscillator by connecting a capacitor, a current source, and current drain to the IN voltage.
    Type: Grant
    Filed: July 7, 1997
    Date of Patent: October 3, 2000
    Assignee: STMicroelectronics, Inc.
    Inventor: William A. Phillips
  • Patent number: 6125094
    Abstract: A current amplifier includes a cascode transistor for fixing the voltage of an input of the amplifier; a first constant current source connected between the input and a first supply voltage; a second constant current source, for providing a current lower than the first current source, connected between a second supply voltage and the cascode transistor; a second transistor, of different type than the cascode transistor, connected between the input and the second supply voltage, and controlled by the node between the cascode transistor and the second current source; and an output transistor of same type as the second transistor, connected to the second supply voltage and controlled by the node.
    Type: Grant
    Filed: April 23, 1998
    Date of Patent: September 26, 2000
    Assignee: STMicroelectronics S.A.
    Inventors: Francis Dell'Ova, Bruno Bonhoure, Frederic Paillardet
  • Patent number: 6124677
    Abstract: A method for testing output connections of at least one driver circuit that drives a plasma display panel. According to the method, at least one output of the driver circuit is switched to a high level for a predetermined time period. The output of the driver circuit is switched to a low level, and the time to discharge the output of the driver circuit with a constant discharge current is measured. It is determined whether a capacitive load is connected to the output of the driver circuit based on the measured time to discharge. In one preferred method, these steps are repeated for each of the outputs of the driver circuit. A driver circuit for driving a plasma display panel is also provided. The driver circuit includes driver output stages, and means for selectively sinking a constant discharge current from the output of at least one of the driver output stages to ground.
    Type: Grant
    Filed: September 27, 1999
    Date of Patent: September 26, 2000
    Assignee: STMicroelectronics S.A.
    Inventors: Celine Lardeau, Gilles Troussel, Eric Benoit
  • Patent number: 6124169
    Abstract: A process creates contacts in semiconductor electronic devices and in particular on bit lines of non-volatile memories with cross-point structure. The cross-point structure includes memory cell matrices in which the bit lines are parallel unbroken diffusion strips extending along a column of the matrix with the contacts being provided through associated contact apertures defined through a dielectric layer deposited over a contact region defined on a semiconductor substrate at one end of the bit lines. The process calls for a step of implantation and following diffusion of contact areas provided in the substrate at opposite sides of each bit line to be contacted to widen the area designed to receive the contacts.
    Type: Grant
    Filed: December 29, 1997
    Date of Patent: September 26, 2000
    Assignee: STMicroelectronics, S.r.l.
    Inventors: Emilio Camerlenghi, Paolo Caprara, Gabriella Fontana
  • Patent number: 6125063
    Abstract: In a memory integrated circuit comprising an internal circuit for the generation of a programming high voltage and comprising a first pad designed to receive a main logic supply voltage below five volts, a second specific supply pad is designed to supply the high voltage generation circuit. This enables the application of a specific logic supply voltage with a voltage level greater than that of the main logic supply voltage in test mode or in application mode.
    Type: Grant
    Filed: September 16, 1998
    Date of Patent: September 26, 2000
    Assignee: STMicroelectronics S.A.
    Inventors: Mohamad Chehadi, David Naura
  • Patent number: 6124746
    Abstract: An adjustable delay circuit, for a logic input signal, comprises circuitry for charging a capacitance at a first constant current when the logic signal switches to a first logic state; circuitry for discharging the capacitance at a second constant current when the logic signal switches to the second logic state; circuitry for stopping charging and discharging of the capacitance between the moment when the voltage across the capacitance reaches a high threshold or a low threshold and a subsequent switching of the logic signal; and a first comparator connected to switch the state of an output signal when the voltage across the capacitance crosses a third threshold included between the first and second thresholds.
    Type: Grant
    Filed: July 29, 1998
    Date of Patent: September 26, 2000
    Assignee: STMicroelectronics S.A.
    Inventor: Klaas Van Zalinge
  • Patent number: 6124765
    Abstract: An integrated oscillator and associated methods are provided for providing clock signals. The integrated oscillator preferably includes a micro-mechanical oscillating circuit for providing an oscillating clock signal. The micro-mechanical oscillating circuit preferably includes a support layer, a fixed layer positioned on a support layer, remaining portions of a sacrificial layer positioned only on portions of the fixed layer, and an oscillating layer positioned on the remaining portions of the sacrificial layer, overlying the fixed layer in spaced relation therefrom, and extending lengthwise generally transverse to a predetermined direction for defining a released beam for oscillating at a predetermined frequency. The spaced relation is preferably formed by removal of unwanted portions of the sacrificial layer.
    Type: Grant
    Filed: October 24, 1997
    Date of Patent: September 26, 2000
    Assignee: STMicroelectronics, Inc.
    Inventors: Tsiu Chiu Chan, Melvin Joseph DeSilva, Syama Sundar Sunkara
  • Patent number: 6124751
    Abstract: An H-bridge circuit having a boost capacitor coupled to the gate of the low-side driver. A driver, in the form of a switching transistor is connected between the load and ground, thus providing a low-side driver. A capacitor is coupled to the gate of the low-side driver to provide a boosted voltage for rapid turn on of the gate. The size of the capacitor selected to be similar to the size of the capacitance associated with the low-side driver transistor.
    Type: Grant
    Filed: June 30, 1997
    Date of Patent: September 26, 2000
    Assignee: STMicroelectronics, Inc.
    Inventor: Albino Pidutti