Patents Represented by Attorney Otho B. Ross, III
  • Patent number: 5317541
    Abstract: A bit decoder for a memory array includes a decode NOR/OR circuit coupled to an output driver circuit. The decode NOR/OR circuit includes a plurality of input signals connected to respective input FET's all of which are connected in parallel between a common source and a common drain node. One input is also connected to an active pullup FET which is connected in series with the input FET's at the common drain node and which is always maintained slightly on. A bipolar transistor pulls down the common drain node and a bleeder FET pulls down the common source node. The output driver is a BICMOS circuit that provides both the bit selection and bit refresh signals which are of opposite phase.
    Type: Grant
    Filed: July 8, 1991
    Date of Patent: May 31, 1994
    Assignee: International Business Machines Corporation
    Inventor: Yuen H. Chan
  • Patent number: 4988893
    Abstract: The invention provides novel implementations of a latch cell in CMOS gate array technology to produce latch dissymmetry and permit a single ended data input. The dissymmetry is produced by increasing the output impedance of the second stage of the latch cell, which can be done, either in a DC or in an AC mode, or even in a mixed version of both modes.
    Type: Grant
    Filed: July 20, 1987
    Date of Patent: January 29, 1991
    Assignee: International Business Machines Corporation
    Inventors: Martine Bonneau, Gerard Boudon, Jean-Claude Le Garrec, Pierre Mollier, Frank Wallart
  • Patent number: 4922455
    Abstract: A transistor memory cell is disclosed of the type wherein an unclamped conducting transistor in each of a plurality of memory cells connected to a given word line is driven into saturation when storing data. The cell is equipped with controlled active devices for discharging the saturation capacitance of the conducting transistors prior to writing new data into the cells. Each active device is characterized with a forward low-impedance current direction and reverse high impedance current direction therethrough for each saturation transistor. Each active device is connected to discharge an associated saturation transistor in its forward current direction. In one embodiment, each active device discharges to a word line when the line is brought to an appropriate control potential. In another embodiment, each active device discharges to a separate discharge line not connected to the work line when the former line is brought to an appropriate control potential. The active devices may be diodes.
    Type: Grant
    Filed: September 8, 1987
    Date of Patent: May 1, 1990
    Assignee: International Business Machines Corporation
    Inventors: William B. Chin, Rudolph D. Dussault, Ronald W. Knepper, Friedrich C. Wernicke, Robert C. Wong
  • Patent number: 4922135
    Abstract: The present invention relates to a family of new GaAs MESFET logic circuits including push pull output buffers, which exhibits very strong output driving capability and very low power consumption at fast switching speeds. A 3 way OR/NOR circuit of this invention includes a standard differential amplifier, the first branch of which is controlled by logic input signals. The second branch includes a current switch controlled by a reference voltage. The differential amplifier provides first and second output signals simultaneously and complementary each other. The circuit further includes two push pull output buffers. The first output buffer comprises an active pull up device connected in series with an active pull down device, and the first circuit output signal is available at their common node or at the output terminal.
    Type: Grant
    Filed: November 14, 1988
    Date of Patent: May 1, 1990
    Assignee: International Business Machines Corporation
    Inventors: Pierre Mollier, Pascal Tannhof
  • Patent number: 4894562
    Abstract: A current switch emitter-follower logic circuit allows both the UP output logic level and the DOWN output logic level to be independently controlled with respect to a fixed reference voltage so as to permit very small output level swings. A feedback circuit generates two different control signals which are independently variable and are input to a control circuit and to a logic circuit to compensate for fluctuations in power supply voltages, temperature and circuit parameters. These control signals are applied to a variable current source within the logic circuit and to a dynamic resistance within the control circuit to compensate almost instantaneously to fluctuations in power supply voltage, temperature or circuit device parameters, maintaining the logic circuit output levels close to reference levels so as to permit small output signal swings. The output logic levels need not be symmetrical around a central reference point.
    Type: Grant
    Filed: October 3, 1988
    Date of Patent: January 16, 1990
    Assignee: International Business Machines Corporation
    Inventors: Joseph R. Cavaliere, George E. Smith, III
  • Patent number: 4871630
    Abstract: Disclosed is a process for reducing lithographic image size for integrated circuit manufacture. A mask of photosensitive material having an opening of a minimum size dictated by the limits of lithography is formed on a substrate. Reduction in the image size is achieved by establishing sidewalls to the interior vertical surfaces of the opening by depositing a conformal layer, followed by anisotropic etching. The dimension of the opening is reduced by the combined thickness of the two opposite insulator sidewalls.In a specific direct application of the disclosed process, a photomask/stencil having a pattern of openings of a minimum size smaller than possible by lighography, per se, is formed.
    Type: Grant
    Filed: July 31, 1987
    Date of Patent: October 3, 1989
    Assignee: International Business Machines Corporation
    Inventors: Nicholas J. Giammarco, Alexander Gimpelson, George A. Kaplita, Alexander D. Lopata, Anthony F. Scaduto, Joseph F. Shepard
  • Patent number: 4796069
    Abstract: A method is disclosed for fabricating a small area, self aligned guard ring in a Schottky barrier diode. A vertically-walled hole is anisotropically etched completely through a dielectric layer on a silicon substrate. A layer of doped polycrystalline silicon is deposited over the apertured dielectric layer. The polycrystalline silicon is reactively ion etched away to leave only a lining about the perimeter of the hole in the dielectric layer. The structure is heated to diffuse the dopant from the lining into the substrate. Schottky diode metal is deposited on the substrate exposed through the lined aperture in the dielectric layer.
    Type: Grant
    Filed: June 18, 1987
    Date of Patent: January 3, 1989
    Assignee: International Business Machines Corporation
    Inventors: Narasipur G. Anantha, Harsaran S. Bhatia, Santosh P. Gaur, John L. Mauer, IV