Patents Assigned to SGS-Thomson Microelectronics, Inc.
  • Patent number: 5689162
    Abstract: A motor drive control circuit for operation in the PWM mode includes a feedack circuit from a resistor for sensing motor coil current modified to switchably connect the resistor to the drive input in accordance with operation of a sample-hold switch. The sample-hold switch is controlled to sample a signal proportional to motor coil current only at the middle of the coil current rise during each PWM ON time, thus providing a reliable indication of average coil current. A signal storage capacitor connected in the feedback circuit receives the sampled signal and retains it for use in feedback control throughout PWM operation until the next sample.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: November 18, 1997
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventor: Larry B. Li
  • Patent number: 5689635
    Abstract: A circuit and method for testing on-chip memory for a microprocessor or a microcomputer is disclosed. The memory test circuit includes an input register, an output register, an adder, and a sequencer to control the test process. The process includes receiving a simple communication protocol from the control unit to start the test, running a common memory test such as a checker board, AAAAh, 5555h and the like, and then storing the test results in an output register. The test circuit can include a bi-directional RESET signal means for disabling the system while the microprocessor or microcomputer runs its memory test.
    Type: Grant
    Filed: December 27, 1995
    Date of Patent: November 18, 1997
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventor: Gianluca Petrosino
  • Patent number: 5683924
    Abstract: A method is provided for forming a planar transistor of a semiconductor integrated circuit, and an integrated circuit formed according to the same. A plurality of field oxide regions are formed overlying a substrate electrically isolating a plurality of transistors encapsulated in a dielectric. LDD regions are formed in the substrate adjacent the transistors and the field oxide regions. Doped polysilicon raised source and drain regions are formed overlying the LDD regions and a tapered portion of the field oxide region and adjacent the transistor. These polysilicon raised source and drain regions will help to prevent any undesired amount of the substrate silicon from being consumed, reducing the possibility of junction leakage and punchthrough as well as providing a more planar surface for subsequent processing steps.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: November 4, 1997
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventors: Tsiu C. Chan, Gregory C. Smith
  • Patent number: 5684393
    Abstract: An integrated transconductor circuit in which the input transistor(s) passes a current across a reference resistor. This conventional arrangement produces current error terms of Vbe/R and Ib. According to the present invention, these terms are compensated by providing a compensation resistor which is matched to the first resistor, and a compensation transistor which is matched to the input transistor, interconnected to feed the appropriate current components to the output. For even better compensation, an additional transistor is optionally added to remove the effect of base current of the compensation transistor. In differential embodiments, the compensation resistor may be bridged or split. Zero, one, or more stages of current mirroring can optionally be used to provide the desired output.
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: November 4, 1997
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventor: Marc Ryat
  • Patent number: 5682055
    Abstract: A method is provided for forming an improved planar structure of a semiconductor integrated circuit, and an integrated circuit formed according to the same. A field oxide is grown across the integrated circuit patterned and etched to form an opening with substantially vertical sidewalls exposing a portion of an upper surface of a substrate underlying the field oxide where an active area will be formed. A gate electrode comprising a polysilicon gate electrode and a gate oxide are formed over the exposed portion of the substrate. The polysilicon gate has a height at its upper surface above the substrate at or above the height of the upper surface of the field oxide. The gate electrode preferably also comprises a silicide above the polysilicon and an oxide capping layer above the silicide. LDD regions are formed in the substrate adjacent the gate electrode and sidewall spacers are formed along the sides of the gate electrode including the silicide and the capping layer.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: October 28, 1997
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventors: Kuei-wu Huang, Tsiu C. Chan, Gregory C. Smith
  • Patent number: 5682052
    Abstract: Therefore, according to the present invention, the isolation between adjacent intra-polycrystalline silicon layer components of one or more polycrystalline silicon layers of an integrated circuit device may be enhanced by patterning and then implanting one or more such polycrystalline silicon layers with a high dose of oxygen or nitrogen, in the range of approximately 1.times.10.sup.19 /cm.sup.2 to 1.times.10.sup.17 /cm.sup.2. A post implant anneal is performed in either nitrogen or argon to form a layer of either silicon dioxide or silicon nitride having desirable planar characteristics. The anneal is performed at a temperature range of approximately 1000 to 1400 degrees Celsius.
    Type: Grant
    Filed: March 29, 1995
    Date of Patent: October 28, 1997
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventors: Robert Louis Hodges, Frank Randolph Bryant
  • Patent number: 5680037
    Abstract: A current mirror uses an operational amplifier to control the collector voltage of two mirroring transistors during operation. The operational amplifier is coupled to the collector of each mirroring transistor such that a differential in voltage between the collector will produce an output voltage which drives a MOS transistor. The MOS transistor, responsive to the output of the operational amplifier, adjusts the voltage at the collector of one of the mirroring transistors to restore equilibrium.
    Type: Grant
    Filed: October 27, 1994
    Date of Patent: October 21, 1997
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventor: Francesco Carobolante
  • Patent number: 5677247
    Abstract: A socketed integrated circuit packaging system, including a packaged integrated circuit and a socket therefor, is disclosed. The integrated circuit package includes a device circuit board to which a thermally conductive slug is mounted; the underside of the device circuit board has a plurality of lands arranged in an array. The integrated circuit chip is mounted to the slug, through a hole in the device circuit board, and is wire-bonded to the device circuit board and thus to the lands on the underside. The socket is a molded frame, having a hole therethrough to receive the conductive slug of the integrated circuit package; the socket may also have its own thermally conductive slug disposed within the hole of the frame. The socket has spring contact members at locations matching the location of the lands on the device circuit board. The integrated circuit package may be inserted into the socket frame, held there by a metal or molded clip.
    Type: Grant
    Filed: October 3, 1996
    Date of Patent: October 14, 1997
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventors: Michael J. Hundt, Anthony M. Chiu
  • Patent number: 5670424
    Abstract: An interconnect structure, and method for forming same, is suitable for use in integrated circuits such as SRAM devices. The structure uses masking of a polycrystalline silicon interconnect level to move a P-N junction to a region within a polycrystalline silicon interconnect line, rather than at the substrate. This P-N junction can then be shorted out using a refractory metal silicide formed on the polycrystalline silicon interconnect structure.
    Type: Grant
    Filed: October 13, 1995
    Date of Patent: September 23, 1997
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventors: Tsiu Chiu Chan, Frank Randolph Bryant, John Leonard Walters
  • Patent number: 5668025
    Abstract: The present application provides a CMOS device and process in which the source/drain regions are polysilicon, and are dielectrically isolated from the well regions. This structure can be obtained, for example, by depositing the first layer of polysilicon under very high temperature conditions (essentially the same as those normally used for epitaxial deposition), so that the first polysilicon layer is formed epitaxially (as monocrystalline silicon) over exposed regions, and as polycrystalline material over oxide. An oxide is grown on the surface of the deposited layer, and a second polysilicon layer is then deposited, under normal conditions, to form the gate layer. After the second polysilicon layer has been patterned, source/drain implants are then made into the first (intrinsic) polysilicon layer to form source/drain implants. Thus, the first polysilicon layer will contain both N+ and P+ regions, and if desired, may also include intrinsic regions.
    Type: Grant
    Filed: February 28, 1995
    Date of Patent: September 16, 1997
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventor: Richard A. Blanchard
  • Patent number: 5668028
    Abstract: A gate structure in a transistor and method for fabricating the structure. A gate structure is formed on a substrate. The gate structure includes three layers: an oxide layer, a nitride layer and a polysilicon layer. The oxide layer is located on the substrate, the nitride layer is located on the oxide layer, and the polysilicon layer is located on the nitride layer. The gate structure is reoxidized to form a layer of oxide over the gate structure.
    Type: Grant
    Filed: April 28, 1995
    Date of Patent: September 16, 1997
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventor: Frank Randolph Bryant
  • Patent number: 5668449
    Abstract: A circuit for operating a polyphase DC motor, such as the type having a plurality of "Y" connected stator coils, has circuitry for charging the coils at a rate which will reduce EMI and other noise, while maintaining an acceptable charge rate. The gate of a selected high side driving transistor is charged at a relatively high rate during a ramping phase. During the ramping phase, the gates of the selected transistor is charged to a voltage near the voltage needed to form a channel in the transistor for conduction. After the ramping phase, the gates are charged at a lesser rate in order to control the rate of charging of the stator coils to prevent noise.
    Type: Grant
    Filed: October 27, 1994
    Date of Patent: September 16, 1997
    Assignee: SGS-THOMSON Microelectronics, Inc.
    Inventor: Francesco Carobolante
  • Patent number: 5666482
    Abstract: According to the present invention, faulty lines of data of a set associative cache memory containing one or more faulty data bits which are not repairable through conventional repair means such as row/column redundancy, are not updated following a cache miss condition and thereby effectively bypassed. Replacement logic circuitry detects and controls the state of a replacement status bit associated with each line of data of the set associative cache memory to determine if the line of data in the cache should be updated or bypassed. Thus, when replacing a line of data, the replacement logic circuitry detects the address of a faulty line of data in a particular set and avoids updating that faulty line of data in favor of updating another line of data of another set.
    Type: Grant
    Filed: September 25, 1996
    Date of Patent: September 9, 1997
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventor: David Charles McClure
  • Patent number: 5666272
    Abstract: A system for packaging integrated circuit components including a ball grid array substrate with a plurality of solder balls coupled to the substrate. A semiconductor device is mounted on the substrate and electrically coupled to the solder balls. One or more terminals are coupled to the substrate and electrically coupled to said semiconductor device. A detachable module contains auxiliary component, such as a data acquisition device, a wireless communications device, an output device or driving devices for a clock circuit. The module comprises a body portion for containing the component and one or more electrical connectors for mating with respective terminals to hold the module to the substrate and to electrically couple the component with the semiconductor device.
    Type: Grant
    Filed: June 3, 1996
    Date of Patent: September 9, 1997
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventors: Dale Thomas Moore, Frank Sigmund, Fred Chevreton
  • Patent number: 5666036
    Abstract: A circuit for driving a motor used to control the HVAC blend door in an automobile is disclosed. The circuit includes an amplifier circuit, an motor, and a three state driver circuit. The driver circut includes three NPN bipolar transistors and two PNP bipolar transistors configured such that the output of the three state driver circuit is turned off if the input is at a intermediate voltage. The output of the three state driver circuit is at a high voltage if the input is at a low voltage. Conversely, the output of the three state driver circuit is at low voltage when the input is at a high voltage.
    Type: Grant
    Filed: May 31, 1995
    Date of Patent: September 9, 1997
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventor: David Frank Swanson
  • Patent number: 5661383
    Abstract: A circuit for controlling the slew rate at a motor coil during turn-on in a commutation sequence is disclosed. The disclosed circuit includes a switched current mirror that receives the commutation signal, and that provides a mirrored current to the input of an integrating buffer amplifier when its associated coil is to be driven. The integrating buffer amplifier includes an amplifier with a feedback capacitor, and a current source connected at its input, for reducing the voltage slew rate during turn-off of the transistor. The mirrored current applied to the input of the integrating buffer amplifier is greater than that of the current source, but limited so as to reduce the voltage slew at the coil.
    Type: Grant
    Filed: September 30, 1994
    Date of Patent: August 26, 1997
    Assignee: SGS-THOMSON Microelectronics, Inc.
    Inventors: Karl M. Schlager, Massimiliano Brambilla
  • Patent number: 5658828
    Abstract: A method for forming an aluminum contact through an insulating layer includes the formation of an opening. A barrier layer is formed, if necessary, over the insulating layer and in the opening. A thin refractory metal layer is then formed over the barrier layer, and aluminum deposited over the refractory metal layer. Proper selection of the refractory metal layer and aluminum deposition conditions allows the aluminum to flow into the contact and completely fill it. Preferably, the aluminum is deposited over the refractory metal layer without breaking vacuum.
    Type: Grant
    Filed: November 30, 1993
    Date of Patent: August 19, 1997
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventors: Yih-Shung Lin, Fu-Tai Liou
  • Patent number: 5657292
    Abstract: A write global bus driver is provided within the data input buffer. The write global bus driver has the same circuit configuration as the read global bus driver so that it drives the output buffer with the very same type of signal and in the same way as the read global bus driver drives the output buffer. The write global bus driver is coupled to the global data bus for placing written data on the global data bus that is normally used only for read data. During each write cycle, the data is written simultaneously to the memory array and to the output buffer. The output buffer is a two-stage, pipelined output buffer. When data is stored in the first stage of the output buffer, whether write data or read data, it is maintained in the first stage on the same clock cycle that it is presented. On the subsequent clock cycle, the data from the first stage is transferred to the second stage and is provided as the output of the output buffer.
    Type: Grant
    Filed: January 19, 1996
    Date of Patent: August 12, 1997
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventor: David C. McClure
  • Patent number: 5656897
    Abstract: A motor drive system, and method for operating the same, which includes current mirror load current sensing, is disclosed. Sensed current is used in the well known manner to control the low side drive of the motor. The disclosed motor system operates in a bipolar mode on startup, and in a unipolar mode during full speed operation. In unipolar mode, a current mirror transistor is provided to sense the load current through the center tap drive transistor in a continuous manner. Ripple in the sensed current is avoided, as the center tap drive transistor is not commutated during motor operation in unipolar mode. In bipolar mode, current mirrors are provided for both of the high side and low side drive transistors in each leg, with the currents summed for each coil at a sum node, and with the summed current applied to a cumulative sum node; the summed current never drops to zero, as only one drive transistor changes in each phase change in the commutation sequence.
    Type: Grant
    Filed: September 30, 1994
    Date of Patent: August 12, 1997
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventors: Francesco Carobolante, Karl Schlager, Li-Hsin D. Lu
  • Patent number: 5656957
    Abstract: A comparator with hysteresis which has a bias current circuit, a differential input stage, and an output stage is disclosed. The differential input stage uses a parallel transistor and an enabling transistor connected in parallel to one of the differential pair transistors to create hysteresis. The parallel transistor and enabling transistor are used to generated an effective offset voltage which must be overcome for the comparator to switch states.
    Type: Grant
    Filed: October 19, 1995
    Date of Patent: August 12, 1997
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventors: C. Allen Marlow, Eric J. Danstrom