Patents Represented by Attorney Lee Patch
  • Patent number: 5173621
    Abstract: Circuit configurations are described for use with split lead leadframes and relatively isolated quiet and noisy power rails to reduce power rail noise and circuit noise. An octal register transceiver circuit incorporates a latch (300) coupled to relatively quiet power rails (42,44) and an output buffer circuit (400) having an input circuit coupled to the latch (300) and relatively quiet power rails (42,44). The output driver transistors (Q433,Q434) of the output buffer circuit (400) are coupled to the relatively noisy output power rails (52,54) to isolate the latch circuit from power rail noise and minimize erroneous operation of the latch. A DC Miller Killer circuit (450) is constructed with delay control components (D456,D457,R460) and an alternative discharge path (R458,D459) to reduce aggravation of power rail noise during operation of DCMK.
    Type: Grant
    Filed: July 12, 1991
    Date of Patent: December 22, 1992
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Dana Fraser, Ray A. Mentzer, Jerry Gray, Geoff Hannington, Susan M. Keown, Gaetan L. Mathieu
  • Patent number: 5149991
    Abstract: An output buffer circuit incorporates a ground bounce blocking circuit which blocks transfer of ground bounce pulses from the output ground lead (GND,PGND) to the output (V.sub.OUT) for protecting quiet outputs tied to a common ground bus. A diode element (SD1,D1,ND1, NSC) is coupled in the sinking current path in series with the primary pulldown transistor element (N1,N1P) between the buffer circuit output (V.sub.OUT) and the ground rail (GND,PGND). The diode element is oriented for passing sinking current to the low potential ground rail and for blocking transfer of ground bounce pulses originating in the ground rail (GND,PGND) to the output. The ground rail may be bifurcated to provide a relatively noisy output ground lead (PGND) and a relatively quiet ground lead (QGND). The primary pulldown transistor element (N1P) is coupled to the relatively noisy output ground lead (PGND).
    Type: Grant
    Filed: June 6, 1991
    Date of Patent: September 22, 1992
    Assignee: National Semiconductor Corporation
    Inventor: Alan C. Rogers
  • Patent number: 5136189
    Abstract: A BiCMOS input circuit which is capable of detecting signals below a particular range, such as ECL signals, is presented. The circuit is useful in conserving the number of pins in a BiCMOS integrated circuit in that a signal below normal ECL levels can trigger special functions, such as testing. The circuit has a plurality of CMOS inverter circuits connected in series with the input node of the first inverter connected to the input terminal of the circuit and the output node of the last inverter circuit connected to the output terminal of the circuit. Diode-connected bipolar transistor created a potential difference between V.sub.CC and the source electrode of PMOS transistor of each CMOS inverter circuit in a declining fashion from the first inverter to the last inverter. The last inverter circuit has no potential difference at all so that its output has a full CMOS swing.
    Type: Grant
    Filed: April 2, 1990
    Date of Patent: August 4, 1992
    Assignee: National Semiconductor Corporation
    Inventor: James E. Demaris
  • Patent number: 5117442
    Abstract: A fault tolerant circuit and method of synchronizing multiple asynchronous input signals, such as reset signals, in a modular redundant fault-tolerant computer system in which clock signals or respective slices have a bounded skew with respect to one another. The input signal and clock signal for each slice of the system are used to produce an initial synchronization signal in each slice of a first layer of the circuit. Each initial synchronization signal is used with an inverted version of each of the slice clock signals to produce, in each slice of a second layer of the circuit, a set of local synchronization signals for each slice. The local synchronization signals for each slice are passed to a majority-voter which produces a voted output signal for the slice. The voted output signal and the clock signal for each slice are then used to produce a finally synchronized output signal for that slice.
    Type: Grant
    Filed: December 14, 1988
    Date of Patent: May 26, 1992
    Assignee: National Semiconductor Corporation
    Inventor: Christopher M. Hall
  • Patent number: 5097489
    Abstract: A method and structure for performing data synchronization by delaying the input data for substantially one-half of the VCO signal period and then comparing the phase of the delayed input data to the VCO signal. The phase difference is filtered and controls the frequency of the VCO signal to align the VCO signal with the delayed input data. The delayed input data is clocked into a flip-flop on the opposite phase of the VCO signal to produce an output signal. In a preferred embodiment the delay of the input data for phase comparison, and the delay of the input data for the output flip-flop can be independently selected.
    Type: Grant
    Filed: May 19, 1989
    Date of Patent: March 17, 1992
    Inventor: Patrick A. Tucci
  • Patent number: 5075885
    Abstract: The present invention provides an ECL EPROM circuit which uses a MOS memory cell. The invention includes a technique for programming the memory cell using MOS voltage levels, and also includes circuitry for reading the memory cell at ECL voltage levels. Thus, the programming and reading paths are split to give the ease of programming and the reprogrammability of MOS EPROM devices combined with the reading speed of PROM devices using ECL voltage levels. In one embodiment, two parallel paths are provided to a memory cell to enable it to separately receive reading and writing (programming) signals. The reading path employs ECL components for reading the cell, while the writing path contains MOS components for programming and verifying the cell. The memory cell itself contains a MOS memory element, an ECL pass element, and a sense element coupling the MOS memory element to the ECL pass element.
    Type: Grant
    Filed: December 21, 1988
    Date of Patent: December 24, 1991
    Assignee: National Semiconductor Corporation
    Inventors: Douglas D. Smith, Robert A. Kertis, Terrance L. Bowman
  • Patent number: 5072275
    Abstract: There is disclosed a static RAM cell and MOS device for making the cell along with a process for making the types of devices disclosed. The devices is an MOS device built in an isolated island of epitaxial silicon similar to bipolar device isolation islands, and has single level polysilicon with self-aligned silicide coating for source, drain and gate contacts such that no contact windows need be formed inside the isolation island to make contact with the transistor. The static RAM cell formed using this device uses extensions of the polysilicon contacts outside the isolation islands as shared nodes to implement the conventional cross coupling of various gates to drain and source electrodes of the other transistors in the flip flop. Similarly, extensions of various gate, source and drain contact electrodes are used as shared word lines, and shared Vcc and ground contacts.
    Type: Grant
    Filed: February 15, 1990
    Date of Patent: December 10, 1991
    Assignee: Fairchild Semiconductor Corporation
    Inventor: Madhukar B. Vora
  • Patent number: 5057718
    Abstract: The present invention provides for a sense amplifier having a pair of input nodes connected through isolating PMOS transistors to the differential input terminals of the amplifier. Each of the input nodes is also connected to the gates of a pair of carefully matched NMOS transistors and to the drain of the other of the matched pair. In addition, each of the input nodes is connected to the gate of one of two drive NMOS transistors. The drains of the drive NMOS transistors are each connected to the gates of two output PMOS transistors, the drains of which form the output terminals of the sense amplifier. The sources of the matched NMOS transistor pair are coupled to ground by a NMOS transistor and the sources of the drive NMOS transistors are coupled to ground by another NMOS transistor. When the differential signals at the input terminals are to be sensed and latched, the sources of matched transistor pair and the sources of the drive transistors are sequentially connected to ground.
    Type: Grant
    Filed: April 3, 1990
    Date of Patent: October 15, 1991
    Assignee: National Semiconductor Corp.
    Inventor: Robert J. Proebsting
  • Patent number: 5057907
    Abstract: An integrated circuit package includes a plurality of TAB assemblies, each including a portion for inner lead bonding an integrated circuit. A portion of the tape is formed to allow the tape to be outer lead bonded to the substrate so that the integrated circuit is mounted at any desired non zero angle with respect to a horizontal substrate. A plurality of formed tape units are outer lead bonded to a horizontal substrate. In one embodiment, the die is inner lead bonded to the tape in an area which is not devoid of tape, allowing electrical traces on the tape which are routed above and not in contact with the surface of the die, thereby providing excellent routing density. The dielectric tape may include a single electrical interconnect layer, or a plurality of electrical interconnect layers which may themselves be electrically interconnected via suitable vias formed within the tape structure.
    Type: Grant
    Filed: June 11, 1990
    Date of Patent: October 15, 1991
    Assignee: National Semiconductor Corp.
    Inventors: Boon K. Ooi, Shiann-Ming Liou, Ka-Heng The, Norman L. Gould
  • Patent number: 5055712
    Abstract: A programmable logic device is constructed having a novel architecture. A plurality of control input signals are applied to a programmable mapping array in order to generate control functions for data path gating, latching, or modification. The programmable control functions provide flexibility to the designer, while the fixed data path logic is independent of the programmable array. The logic array and data path logic are fabricated on the same integrated circuit, therefore obviating the need for input/output buffers which would be necessary if the device were constructed utilizing discrete components. This enhances the performances of the device. Since the data path does not travel through the array, its performance is not affected by the programmability. If desired, the programmable array can be formed of mask programmable devices, fused programmable devices, or register based circuitry, for example, using RAM cells.
    Type: Grant
    Filed: April 5, 1990
    Date of Patent: October 8, 1991
    Assignee: National Semiconductor Corp.
    Inventors: David W. Hawley, Scott K. Pickett, Frederick K. Y. Leung
  • Patent number: 5055705
    Abstract: A novel voltage selection circuit in which only one of a plurality of voltage levels is selected for application to an output node at any given time. Switching transistors are connected between the output node and associated reference voltages. Switching transistors are controlled by a set of voltage selection signals, each having logical zero and logical one states which are of sufficient magnitude to cause said switching transistors to turn on or turn off, and which are insured to be nonoverlapping. Two of the voltages are ground and VCC, which are switched by associated transistors using voltage selection signals having standard levels, such as ground and VCC. Another voltage VPPP is greater than VCC, and is switched by a switching transistor utilizing a voltage selection signal greater than VCC, preferably equal to VPPP. The wells of the second and third switching transistors are connected in common to VPPP to prevent junction breakdown when VPPP is selected.
    Type: Grant
    Filed: February 15, 1990
    Date of Patent: October 8, 1991
    Assignee: National Semiconductor Corp.
    Inventor: Christopher M. Hall
  • Patent number: 5051690
    Abstract: Vertically propagated defects in integrated circuits are detected utilizing an apparatus which includes a first meander structure formed on or in a substrate and a second meander structure electrically insulated from the first meander. Each meander includes intermediate segments, the ends of which are interconnected by folded segments. A first set metal of strips are electrically insulated from the first and second meanders. The ends of each strip in the first set are electrically connected to the ends of a corresponding intermediate segment of the first meander. A second set metal or strips are electrically insulated from the first set of strips, the first meander and the second meander. The ends of each strip in the second set are electrically connected to the ends of a corresponding intermediate segment of the second meander and at least a portion of the second set of strips overlies at least a portion of the first set of strips.
    Type: Grant
    Filed: May 26, 1989
    Date of Patent: September 24, 1991
    Assignee: National Semiconductor Corporation
    Inventors: Wojciech Maly, Michael E. Thomas
  • Patent number: 5051623
    Abstract: The lower output pulldown tristate circuit for a TTL tristate output buffer circuit includes the enable signal invertor buffer having an OE signal input and an OE signal output providing output enable OE signals, and a Miller killer transistor element having collector and emitter nodes coupled between the base node of the TTL tristate output pulldown transistor and the low potential power rail. The base node of an emitter follower transistor element is coupled to the OE signal input and the emitter node provides a DC Miller killer DCMK signal output in phase with the OE signal input. A voltage divider couples the DCMK signal output to the base node of the Miller killer transistor element for discharging the base of the output pulldown transistor in response ot a high potential DCMK signal during the high impedance tristate at the output. The DC Miller killer circuit is applied in a high speed TTL tristate output and multi-bit line driver.
    Type: Grant
    Filed: June 16, 1990
    Date of Patent: September 24, 1991
    Assignee: National Semiconductor Corporation
    Inventors: Roy L. Yarbrough, Julio R. Estrada
  • Patent number: 5049763
    Abstract: Low noise circuits for single stage and multi-stage circuits reduce power rail noise, including both ground noise and supply noise caused by output power rail ground lead and supply lead inductance. Anti-bounce circuits reduce ground bounce by suppressing turn on of the output stage pulldown transistor element during transient occurrence of ground bounce events. Similarly anti-droop circuits reduce output supply V.sub.cc droop by suppressing turn on of the output stage pulldown transistor element during transient occurrence of V.sub.cc droop events. Anti-undershoot circuits dissipate ground undershoot energy by establishing a transient sacrificial current flow through the parasitic output ground tank circuit following transition from high to low potential at the output and by prolonging the sacrificial current flow during transient occurrence of ground undershoot events.
    Type: Grant
    Filed: March 22, 1989
    Date of Patent: September 17, 1991
    Assignee: National Semiconductor Corporation
    Inventor: Alan C. Rogers
  • Patent number: 5045916
    Abstract: There is disclosed a process for making high performance bipolar and high performance MOS devices on the same integrated circuit die. The process comprises forming isoaltion islands of epitaxial silicon surrounded by field oxide and forming MOS transistors having polysilicon gates in some islands and forming bipolar transistors having polysilicon emitters in other islands. Insulating spacers are then formed around the edges of the polysilicon electrodes by anisotropically etching a layer of insulation material, usually thermally grown silicon dioxide covered with additional oxide deposited by CVD. A layer of refractory metal, preferably titanium covered with tungsten, is then deposited and heat treated at a temperature high enough to form only titanium disilicide to form silicide over the tops of the polysilicon electrodes and on top of the bases, sources and drains.
    Type: Grant
    Filed: July 19, 1989
    Date of Patent: September 3, 1991
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Madhukar B. Vor, Gregory N. Burton, Ashok K. Kapoor
  • Patent number: 5045729
    Abstract: A TTL/ECL translation circuit for translating TTL level input signals, which have a high voltage state and a low voltage state, to ECL level output signals, which have a high voltage state and a low voltage state. The translation circuit includes a TTL input circuit, a level shifter, and an ECL output circuit connected in series. The TTL input circuit receives the TTL level input signals and generates a first intermediate signal, corresponding to the TTL level input signals, that is transmitted to the level shifter. The level shifter receives the first intermediate signal and generates a second intermediate signal corresponding to the first intermediate signal that is transmitted to the ECL output circuit. The ECL output circuit receives the second intermediate signal and generates an ECL output signal corresponding to the second intermediate signal and the TTL input signal.
    Type: Grant
    Filed: November 15, 1989
    Date of Patent: September 3, 1991
    Assignee: National Semiconductor Corporation
    Inventors: Loren Yee, Nguyen X. Sinh
  • Patent number: 5041721
    Abstract: A machine provides automated counting of integrated circuit (IC) parts packed in a shipping tube which may be, for example, an opaque shipping rail for translation of the rail along the track. An elongate support or track receives and holds a shipping rail. A first rail sensor positioned adjacent to the track senses the presence of a rail on the support track and generates a start count signal. A second rail sensor positioned along the track generates a stop count signal after the scanning of the rail by the sensors is completed. An IC parts sensor provided by an inductive proximity sensor is positioned adjacent to the track between the first and second rail sensors and senses the presence of IC parts contained in the shipping rail. A roller drive translates the shipping rail and the sensors relative to each other for scanning of the rail by the sensors. The parts sensor generates parts counting signals from the start count signal to the stop count signal.
    Type: Grant
    Filed: March 22, 1990
    Date of Patent: August 20, 1991
    Assignee: National Semiconductor Corporation
    Inventors: Clarence A. Smith, Roger H. Doherty, Raymond A. Roberts
  • Patent number: 5041903
    Abstract: An integrated circuit package includes a plurality of TAB assemblies, each including a portion for inner lead bonding an integrated circuit. A portion of the tape is formed to allow the tape to be outer lead bonded to the substrate so that the integrated circuit is mounted at any desired non zero angle with respect to a horizontal substrate. A plurality of formed tape units are outer lead bonded to a horizontal substrate. In one embodiment, the die is inner lead bonded to the tape in an area which is not devoid of tape, allowing electrical traces on the tape which are routed above and not in contact with the surface of the die, thereby providing excellent routing density. The dielectric tape may include a single electrical interconnect layer, or a plurality of electrical interconnect layers which may themselves be electrically interconnected via suitable vias formed within the tape structure.
    Type: Grant
    Filed: June 11, 1990
    Date of Patent: August 20, 1991
    Assignee: National Semiconductor Corp.
    Inventors: Michael A. Millerick, Gregory W. Pautsch
  • Patent number: 5039892
    Abstract: In accordance with teachings of this invention a novel sense amplifier is provided. The sense amplifier includes an enable circuit which receives an enable input signal. This enable circuit includes a constant current source which consumes a small amount of power. The enable circuit provides an output signal which serves to disable the output pull up and pull down transistors of the sense amplifier, thereby providing a high impedance output signal. At the same time, the disabling output signal from the enable circuitry powders down the read circuitry, thereby minimizing power consumption.
    Type: Grant
    Filed: June 7, 1990
    Date of Patent: August 13, 1991
    Assignee: National Semiconductor Corporation
    Inventor: Thomas M. Luich
  • Patent number: 5036222
    Abstract: An output buffer for reducing switching induced noise in high speed integrated circuit devices incorporates a relatively small current carrying capacity secondary pulldown transistor element with the current path first and second terminal leads coupled in parallel with the current path first and second terminal leads of the primary pulldown transistor element. A first output voltage sensing switching circuit is coupled in series between the control terminal leads of the secondary and primary pulldown transistor elements. The secondary pulldown transistor element control terminal lead is coupled in the output buffer to receive a signal propagating through the output buffer first. A relatively small discharge current is therefore initiated from the output before turn on of the relatively large discharge current of the primary pulldown transistor element.
    Type: Grant
    Filed: February 22, 1990
    Date of Patent: July 30, 1991
    Assignee: National Semiconductor Corporation
    Inventor: Jeffrey B. Davis