Patents Assigned to STMicroelectronics
  • Patent number: 6072682
    Abstract: A protection circuit for a power supply line in a semiconductor device, comprising first and second field-effect transistors, both transistors having their respective drain terminals connected to the power supply line. The gate source terminals of the first transistor are connected to ground through first and second resistors, respectively. The gate and source terminals of the second transistor are connected to the source terminal of the first transistor and to ground, respectively.
    Type: Grant
    Filed: December 30, 1997
    Date of Patent: June 6, 2000
    Assignee: STMicroelectronics S.r.l.
    Inventors: Enrico M. A. Ravanelli, Luca Fontanella
  • Patent number: 6072335
    Abstract: An output current unit comprises a cascode circuit having a first transistor connected between a voltage supply line and complementary outputs. Second and third transistors are controlled by inverter circuitry having parallel conducting paths between an output node and a ground line, the parallel conducting paths having different current carrying capacity with control circuitry to switch the stronger of the current carrying paths.
    Type: Grant
    Filed: November 18, 1997
    Date of Patent: June 6, 2000
    Assignee: STMicroelectronics Limited
    Inventor: Peter William Hughes
  • Patent number: 6071778
    Abstract: A memory device comprising a semiconductor material substrate with a dopant of a first type; a first semiconductor material well with a dopant of a second type formed in the substrate; a second semiconductor material well with a dopant of the first type formed in said first well; an array of memory cells formed within said second well. Each memory cell comprises a first electrode and a second electrode respectively formed by a first and a second doped regions with dopant of the second type formed in said second well, and a control gate electrode.
    Type: Grant
    Filed: September 3, 1999
    Date of Patent: June 6, 2000
    Assignee: STMicroelectronics S.r.l.
    Inventors: Roberto Bez, Alberto Modelli
  • Patent number: 6072339
    Abstract: A current sensing circuit with high input impedance comprises a first transconductance amplifier connected across the terminals of a resistor, through which a current to be measured flows. A voltage amplifier is cascade-connected to the first transconductance amplifier. A second transconductance amplifier is feedback connected between an output of the voltage amplifier and a virtual ground node of the voltage amplifier. A ratio between the output voltage of the voltage amplifier and the voltage across the resistor are equal, in absolute value, to a ratio of the transconductances of the first and second transconductance amplifiers.
    Type: Grant
    Filed: November 4, 1998
    Date of Patent: June 6, 2000
    Assignee: STMicroelectronics S.r.l
    Inventor: Luca Bertolini
  • Patent number: 6072727
    Abstract: The invention relates to a dynamic sense amplifier, particularly for semiconductor memory devices of the EPROM, EEPROM and Flash-EPROM types, which includes a virtual ground sense circuit having a pair of output nodes, an equilibration device for equalizing the voltages at the output nodes, and respective reference and matrix circuit legs associated with the output nodes and being led to respective input terminals, the sense amplifier also includes a bias circuit portion for biasing the input terminals. The inventive amplifier distinguishes itself in that the sense circuit and equilibration device are driven by respective signals to generate a predetermined differential voltage between the output nodes before the sense circuit is activated.
    Type: Grant
    Filed: April 29, 1998
    Date of Patent: June 6, 2000
    Assignee: STMicroelectronics S.r.l.
    Inventor: Francesco La Rosa
  • Patent number: 6071786
    Abstract: A method of manufacturing a bipolar transistor in an integrated circuit including the steps of forming a P-type base area, coating this base area with an isolating layer, and forming an opening in the isolating layer at a location where it is desired to form the emitter region. The method further includes coating the structure with an N-type doped polysilicon layer, etching the polysilicon layer to delimit a portion therefrom, forming spacers at a periphery of the polysilicon portion, and implanting a P-type dopant to form a base contact making region, after masking the polysilicon portion, above the area where it is in contact with the base area.
    Type: Grant
    Filed: April 14, 1998
    Date of Patent: June 6, 2000
    Assignee: STMicroelectronics, S.A.
    Inventor: Michel Laurens
  • Patent number: 6069399
    Abstract: A transistor including an epitaxial layer with a first conductivity type, a base buried region with a second conductivity type, and a sinker base region with the second conductivity type which extends from a main surface of the transistor to the base buried region, and delimits, together with the base buried region, emitter fingers in the epitaxial layer. The transistor further includes an emitter buried region with the first conductivity type and a doping level which is higher than that of the epitaxial layer. The emitter buried region is embedded in the epitaxial layer in a position adjacent to the base buried region. A sinker emitter region having the first conductivity type and a doping level which is higher than that of the epitaxial layer and extends from the main surface to the emitter buried region inside the emitter fingers.
    Type: Grant
    Filed: May 15, 1998
    Date of Patent: May 30, 2000
    Assignee: STMicroelectronics S.r.l.
    Inventor: Davide Patti
  • Patent number: 6069385
    Abstract: A low-voltage high-current discrete insulated-gate field-effect transistor which is made by a very economical process with two silicon etches. A buried poly gate gates conduction along a trench sidewall. The channel is provided by the residuum of an epi layer, and the source diffusion is provided by an unmasked implant which is screened only by various grown oxides.
    Type: Grant
    Filed: April 9, 1998
    Date of Patent: May 30, 2000
    Assignee: STMicroelectronics, Inc.
    Inventor: Richard A. Blanchard
  • Patent number: 6069513
    Abstract: A toggle flip-flop with reduced integration area, comprising a flip-flop of the D-type with an inverting input stage and a master-slave portion. Three transistors connected to the inverting stage form a logic gate of the XOR type whereto the output terminal of the master-slave portion is fed back.
    Type: Grant
    Filed: August 28, 1998
    Date of Patent: May 30, 2000
    Assignee: STMicroelectronics S.r.l.
    Inventors: Annamaria Rossi, Giona Fucili, Marcello Leone, Maurizio Nessi
  • Patent number: 6069837
    Abstract: A row decoding circuit for an electronic memory cell device, particularly in low supply voltage applications, is described. The row decoding circuit is adapted to boost, through at least one boost capacitor, a read voltage to be applied to a memory column containing a memory cell to be read. The circuit is powered between a first supply voltage reference and a second ground potential reference, and comprises a hierarchic structure of cascade connected inverters and a circuit means of progressively raising the read voltage level dynamically. First means are provided for raising the read voltage level to a value equal to the supply voltage plus a threshold voltage, and second means are provided for raising the read voltage level to a value equal to the supply voltage plus twice said threshold voltage.
    Type: Grant
    Filed: December 29, 1998
    Date of Patent: May 30, 2000
    Assignee: STMicroelectronics, S.r.l.
    Inventors: Rino Micheloni, Giovanni Campardo, Donato Ferrario, Stefano Ghezzi
  • Patent number: 6069822
    Abstract: The programming method comprises the steps of applying a programming pulse to a first cell and simultaneously verifying the present threshold value of at least a second cell; then verifying the present threshold value of the first cell and simultaneously applying a programming pulse to the second cell. In practice, during the entire programming operation, the gate terminal of both the cells is biased to a same predetermined gate voltage and the source terminal is connected to ground; the step of applying a programming pulse is carried out by biasing the drain terminal of the cell to a predetermined programming voltage and the step of verifying is carried out by biasing the drain terminal of the cell to a read voltage different from the programming voltage. Thereby, switching between the step of applying a programming pulse and verifying is obtained simply by switching the drain voltage of the cells.
    Type: Grant
    Filed: October 27, 1998
    Date of Patent: May 30, 2000
    Assignee: STMicroelectronics S.r.l.
    Inventors: Roberto Canegallo, Ernestina Chioffi, Marco Pasotti, Danilo Gerna, Pier Luigi Rolandi
  • Patent number: 6067250
    Abstract: Method for localizing point defects causing column leakage currents in a non-volatile memory device, said device including a plurality of memory cells arranged in rows and columns in a matrix structure, the columns being connected to drain regions by first contacts, source diffusions, and metal lines which connect the source diffusions to each other by second contacts. The method includes the steps of modifying the memory device in order to eliminate a part of the first contacts and all the second contacts, and to form third contacts, which connect the metal lines to drain regions in rows wherein the first contacts have been eliminated, making the source diffusions independent of each other and halving the initial number of the memory cells; sequentially biasing the single columns of the matrix; sequentially biasing the single rows of the matrix, keeping biased one column; localizing a memory cell which presents the point defects, when the leakage current flow occurs.
    Type: Grant
    Filed: May 13, 1999
    Date of Patent: May 23, 2000
    Assignee: STMicroelectronics S.R.L.
    Inventors: Leonardo Ravazzi, Giuseppe Crisenza
  • Patent number: 6067263
    Abstract: A dynamic random access memory (DRAM) circuit is provided that utilizes a testing system and method to determine the sensitivity of a sense amplifier. More specifically, the DRAM circuit, in determining the sensitivity of the sense amplifier, utilizes a testing system to independently control the magnitude of a voltage differential appearing between a pair of bit lines and sensed by the sense amplifier. The sensitivity of the sense amplifier is then able to be determined by monitoring an input/output signal in response to sensing the known voltage differential. The testing system controls the magnitude of the voltage differential appearing between the bit lines by enabling a first dummy cell to transfer a first reference charge onto a first bit line and by enabling a second dummy cell to transfer a second reference charge onto a second bit line.
    Type: Grant
    Filed: April 7, 1999
    Date of Patent: May 23, 2000
    Assignee: STMicroelectronics, Inc.
    Inventor: James Brady
  • Patent number: 6067025
    Abstract: An apparatus and method for controlling the height of packaging above an integrated circuit package (30) comprising, a substrate (12), a silicon chip (16) and a signal wire (20), one or more height detection wires (32) extending above the top surface (26) of the silicon chip (16) and the signal wire (20) and a detector electrically connected to the height detection wire (32), wherein the height detection wire (32) and the detector form an electric circuit that is affected when a polisher of encapsulant (40) is in proximity to the height detection wire (32), is disclosed.
    Type: Grant
    Filed: December 3, 1997
    Date of Patent: May 23, 2000
    Assignee: STMicroelectronics, Inc.
    Inventors: Anthony M. Chiu, Alan H. Kramer
  • Patent number: 6067198
    Abstract: A device comprises a variable-gain input amplifier, a low-pass analog filter, a transversal continuous-time analog filter, and two distinct and parallel sampling channels interposed between the transversal analog filter and an RLL-NRZ decoder. The two sampling channels each comprise an analog-to-digital converter and a Viterbi detector arranged in series and operating according to sampling sequences that alternate with one another.
    Type: Grant
    Filed: May 23, 1995
    Date of Patent: May 23, 2000
    Assignee: STMicroelectronics S.r.l.
    Inventors: Maurizio Zuffada, Paolo Gadducci, David Moloney, Roberto Alini
  • Patent number: 6067655
    Abstract: A burst error limiting symbol detector system includes a symbol detector circuit responsive to a truncated sample signal for detecting binary symbols encoded in a truncated sample signal with reference to at least one preselected reference level; a feedback equalizer circuit for providing a feedback equalizer signal for cancelling undesired samples in an input signal; a summing circuit, responsive to the input signal and the feedback equalizer signal for providing the truncated sample signal to the symbol detector circuit; and a feedback suppressor circuit responsive to the truncated sample being within a predetermined range of the preselected reference level for suppressing the feedback equalizer signal to prevent marginal detected binary symbols from contributing to the cancellation of undesired samples in the input signal.
    Type: Grant
    Filed: August 28, 1997
    Date of Patent: May 23, 2000
    Assignee: STMicroelectronics, N.V.
    Inventors: Janos Kovacs, Ronald Kroesen, Jason Byrne
  • Patent number: 6064535
    Abstract: A system for halting operation of a hard disk controller when a write operation occurs during a servo positioning error condition including a memory cell for retaining an indication of whether a write operation occurred during the previous servo sector. A memory cell, such as a flip flop, is set on any occurrence of a write operation. With the reading of a next servo field, the output of the first flip flop is latched to a second flip flop. During a present servo sector, a servo positioning error signal is logically AND'ed with a write gate active signal where the write gate active signal is enabled if write gate is active in the present servo sector or write gate was active in the previous servo sector (as indicated by the output from the second flip flop.
    Type: Grant
    Filed: August 14, 1997
    Date of Patent: May 16, 2000
    Assignee: STMicroelectronics, N.V.
    Inventors: Aaron W. Wilson, Russell B. Josephson, Wen Lin, Wayne A. Thorsted
  • Patent number: 6064077
    Abstract: A method for fabricating an integrated circuit transistor begins with doping the substrate in the device active areas after field oxide regions have been formed. This dopant helps to reduce short channel transistor effects. A thin layer of epitaxial silicon is then grown over the substrate active regions. A field effect transistor is formed in the epitaxial layer and underlying substrate. The transistor channel region is in the relatively lightly doped epitaxial layer, but the underlying doped substrate layer helps minimize short channel effects.
    Type: Grant
    Filed: December 6, 1994
    Date of Patent: May 16, 2000
    Assignee: STMicroelectronics, Inc.
    Inventor: Ravishankar Sandaresan
  • Patent number: 6064594
    Abstract: A voltage boosting circuit for use in an integrated circuit having at least four driving voltage phases that include first and second voltage phases with amplitudes substantially equal to the supply voltage, and first and second boosted voltage phases. The voltage boosting circuit includes an input that receives the first or second voltage phase, an output that supplies the first or second boosted voltage phase, and a charge node that is coupled to the input. Additionally, a supply voltage precharge circuit precharges the charge node, and an additional transistor is connected between the supply voltage and the charge node. The additional transistor is driven by a voltage with a greater amplitude than the supply voltage so that the charge node is precharged up to the supply voltage and the first or second boosted voltage phase that is output by the voltage boosting circuit reaches an amplitude equal to substantially twice the supply voltage.
    Type: Grant
    Filed: February 26, 1999
    Date of Patent: May 16, 2000
    Assignee: STMicroelectronics S.r.l.
    Inventors: Carmela Calafato, Maurizio Gaibotti
  • Patent number: 6064556
    Abstract: A protection circuit for a pulse type power supply line of an integrated circuit device. The protection circuit includes a switching circuit having a preset delay, and a first transistor that is connected between the pulse power supply line and ground. The gate terminal of the first transistor is coupled to ground through a first resistor, and to a second power supply line for a low DC voltage through the switching circuit. In a preferred embodiment, the switching circuit includes a second transistor that is connected between the gate terminal of the first transistor and ground. The gate terminal of the second transistor is coupled to the second power supply line through a current generator, and is also coupled to ground through a resistive element and a capacitive element that are connected in parallel.
    Type: Grant
    Filed: September 30, 1998
    Date of Patent: May 16, 2000
    Assignee: STMicroelectronics S.r.l.
    Inventor: Enrico M. A. Ravanelli