Patents Assigned to Thunderbird Technologies, Inc.
  • Patent number: 5357480
    Abstract: An address change detection system detects a change in an address input in a memory to initiate a read or write operation. The address change detection system uses a transition detection delay unit for each address bit of the memory. The transition detection delay unit is responsive to a change in an associated address bit to provide a clock output pulse of predetermined duration. The transition detection delay unit comprises a latch which is coupled to the associated address bit, and a pair of Delay Ring Segment Buffers, each coupled to a respective output of the latch. The output of the Delay Ring Segment Buffer is provided to cascaded NAND gates to form the output of the transition detection delay unit. The outputs of all of the transition detection delay units are provided to an OR gate, the output of which provides an indication of an address change.
    Type: Grant
    Filed: February 25, 1994
    Date of Patent: October 18, 1994
    Assignee: Thunderbird Technologies, Inc.
    Inventor: Albert W. Vinal
  • Patent number: 5304874
    Abstract: A differential latching inverter uses a pair of cross-coupled inverters having a skewed voltage transfer function to rapidly sense a differential signal on a pair of bit lines in a random access memory and provide high speed sensing during a read operation. The differential latching inverter may also include a pair of symmetrical transfer function output inverters and additional pull-up circuits to enhance high speed operation. The differential latching inverter may be used in a memory architecture having primary bit lines and signal bit lines, with a differential latching inverter being connected to each pair of signal bit lines. The primary bit lines and signal bit lines are coupled to one another during read and write operations and decoupled from one another otherwise. The read and write operations may be internally timed without the need for external clock pulses in response to a high speed address change detection system, and internal timing signals generated by delay ring segment buffers.
    Type: Grant
    Filed: May 31, 1991
    Date of Patent: April 19, 1994
    Assignee: Thunderbird Technologies, Inc.
    Inventor: Albert W. Vinal
  • Patent number: 5305269
    Abstract: A differential latching inverter uses a pair of cross-coupled inverters having a skewed voltage transfer function to rapidly sense a differential signal on a pair of bit lines in a random access memory and provide high speed sensing during a read operation. The differential latching inverter may also include a pair of symmetrical transfer function output inverters and additional pull-up circuits to enhance high speed operation. The differential latching inverter may be used in a memory architecture having primary bit lines and signal bit lines, with a differential latching inverter being connected to each pair of signal bit lines. The primary bit lines and signal bit lines are coupled to one another during read and write operations and decoupled from one another otherwise. The read and write operations may be internally timed without the need for external clock pulses in response to a high speed address change detection system, and internal timing signals generated by delay ring segment buffers.
    Type: Grant
    Filed: August 7, 1991
    Date of Patent: April 19, 1994
    Assignee: Thunderbird Technologies, Inc.
    Inventor: Albert W. Vinal
  • Patent number: 5247212
    Abstract: A high speed low Capacitance Complementary Logic Input Parallel (CLIP) logic family includes an FET driving stage, a complementary FET inverter, and at least one gating FET. The dimensions of the gating FET are controlled relative to the dimensions of the driving stage FETs to provide a high speed logic circuit. AND and OR CLIP logic circuits may be provided. A clocked CLIP logic circuit may be provided by adding a clocking FET. A latching clocked CLIP logic circuit may also be provided by adding a latching FET. In the latching clocked CLIP logic circuit, the gate output is latched so that it does not change during the clock period regardless of changes in the logic inputs of the circuit. The speed of the CLIP logic circuits may be further increased by including germanium in the channel of its P-channel FETs to thereby increase carrier mobility in the P-channel FETs. The N-channel FETs are free of germanium.
    Type: Grant
    Filed: January 31, 1991
    Date of Patent: September 21, 1993
    Assignee: Thunderbird Technologies, Inc.
    Inventor: Albert W. Vinal
  • Patent number: 5222039
    Abstract: A static random access memory (SRAM) cell uses a pair of conventional cross-coupled MOSFET devices including an inversion layer, and a pair of inversion-free Fermi threshold FET devices, of the same conductivity type as the cross-coupled transistor pair, for resistive loads. The Fermi-FETs provide a high valued resistor, the value of which is independent of current variations and which is easily fabricated without the need to control polycrystalline silicon grain size. The Fermi-FETs may also provide temperature compensation of the SRAM cell so that it is operable over a wide range of temperature. Fermi-FETs may also be used for the pass transistors of the SRAM cell with the Fermi-FET's low gate capacitance minimizing the loading of the word line. A high speed, dense SRAM cell is provided. The Fermi-FET may also be used in other applications which require low input capacitance, high value constant resistance and temperature compensation.
    Type: Grant
    Filed: November 28, 1990
    Date of Patent: June 22, 1993
    Assignee: Thunderbird Technologies, Inc.
    Inventor: Albert W. Vinal
  • Patent number: 5194923
    Abstract: An improved Fermi FET structure with low gate and diffusion capacity allows conduction carriers to flow within the channel at a predetermined depth in the substrate below the gate, without requiring an inversion layer to be created at the surface of the semiconductor. The low capacity Fermi FET is preferably implemented using a Fermi Tub having a predetermined depth, and with a conductivity type opposite the substrate conductivity type and the same conductivity type as the drain and source diffusions.
    Type: Grant
    Filed: January 28, 1992
    Date of Patent: March 16, 1993
    Assignee: Thunderbird Technologies, Inc.
    Inventor: Albert W. Vinal
  • Patent number: 5151759
    Abstract: A Silicon-on-Insulator (SOI) field effect transistor (FET) operates in the enhancement mode without requiring inversion by setting the device's threshold voltage to twice the Fermi potential of the thin semiconductor layer in which the transistor is fabricated. The FET, referred to as a Fermi Threshold SOI FET or Fermi SOI FET, has a threshold voltage which is independent of oxide thickness, channel length, drain voltage and substrate channel doping. The vertical electric field in the substrate channel becomes zero, thereby maximizing carrier mobility, and minimizing hot electron effects. The thin silicon layer in which the devices are formed is sufficiently thick such that the channel is not fully depleted at pinch-off. A high speed device, substantially independent of device dimensions is thereby provided, which may be manufactured using relaxed groundrules, to provide low cost, high yield devices.
    Type: Grant
    Filed: January 25, 1991
    Date of Patent: September 29, 1992
    Assignee: Thunderbird Technologies, Inc.
    Inventor: Albert W. Vinal
  • Patent number: 5105105
    Abstract: A logic and memory family using CMOS technology operates at high speeds using a Ring Segment Buffer to couple logic gates to one another in an integrated circuit chip, and to couple memory cells to other circuits to provide shift registers, triggers, clock pulse generators and other memory related circuits. The Ring Segment Buffer comprises one or more serially connected complementary field effect transistor (FET) inverter stages, with the output of a preceding stage being connected to the input of a succeeding stage. The N-channel FET in each inverter stage has a channel width which is less than a predetermined factor (K) times the width of the N-channel of the immediately preceding stage. By maintaining the K channel width relationship, the Ring Segment Buffer can drive large capacitive loads at high speed. The Ring Segment Buffer may also provide a predetermined delay which is a function of channel length and the number of stages.
    Type: Grant
    Filed: April 19, 1991
    Date of Patent: April 14, 1992
    Assignee: Thunderbird Technologies, Inc.
    Inventor: Albert W. Vinal
  • Patent number: 5030853
    Abstract: A logic and memory family using CMOS technology operates at high speeds using a Ring Segment Buffer to couple logic gates to one another in an integrated circuit chip, and to couple memory cells to other circuits to provide shift registers, triggers, clock pulse generators and other memory related circuits. The Ring Segment Buffer comprises one or more serially connected complementary field effect transistor (FET) inverter stages, with the output of a preceding stage being connected to the input of a succeeding stage. The N-channel FET in each inverter stage has a channel width which is less than a predetermined factor (K) times the width of the N-channel of the immediately preceding stage. By maintaining the K channel width relationship, the Ring Segment Buffer can drive large capacitive loads at high speed. The Ring Segment Buffer may also provide a predetermined delay which is a function of channel length and the number of stages.
    Type: Grant
    Filed: March 21, 1990
    Date of Patent: July 9, 1991
    Assignee: Thunderbird Technologies, Inc.
    Inventor: Albert W. Vinal
  • Patent number: 5001367
    Abstract: A high speed, high density, low power dissipation all parallel FET logic circuit includes a driving stage having a plurality of parallel FETs of a first conductivity type for receiving logic input signals and a load FET of second conductivity type connected to the common output of the driving stage. A complementary FET inverter including serially connected FETs of first and second conductivity type is connected to the common output and the load FET. According to the invention the voltage transfer function of the complementary inverter is skewed so that the product of the carrier mobility and the ratio of channel width to length of the inverter FET of the first conductivity type is made substantially greater than the product of the carrier mobility and the ratio of channel width to length of the inverter FET of the second conductivity type. By skewing the voltage transfer function of the complementary inverter the voltage lift-off interval is dramatically decreased, thereby improving the speed.
    Type: Grant
    Filed: April 14, 1989
    Date of Patent: March 19, 1991
    Assignee: Thunderbird Technologies, Inc.
    Inventor: Albert W. Vinal
  • Patent number: 4990974
    Abstract: A field effect transistor (FET) operates in the enhancement mode without requiring inversion by setting the device's threshold voltage to twice the Fermi potential of the semiconductor material. The FET, referred to as a Fermi Threshold FET or Fermi-FET, has a threshold voltage which is independent of oxide thickness, channel length, drain voltage and substrate doping. The vertical electric field in the channel becomes zero, thereby maximizing carrier mobility, and minimizing hot electron effects. A high speed device, substantially independent of device dimensions is thereby provided, which may be manufactured using relaxed groundrules, to provide low cost, high yield devices.Temperature dependence of threshold voltage may also be eliminated by providing a semiconductor gate contact which neutralizes the effect of substrate contact potential.
    Type: Grant
    Filed: March 2, 1989
    Date of Patent: February 5, 1991
    Assignee: Thunderbird Technologies, Inc.
    Inventor: Albert W. Vinal
  • Patent number: 4984043
    Abstract: A field effect transistor (FET) operates in the enhancement mode without requiring inversion by setting the device's threshold voltage to twice the Fermi potential of the semiconductor material. The FET, referred to as a Fermi Threshold FET or Fermi-FET, has a threshold voltage which is independent of oxide thickness, channel length, drain voltage and substrate doping. The vertical electric field in the channel becomes zero, thereby maximizing carrier mobility, and minimizing hot electron effects. A high speed device, substantially independent of device dimensions is thereby provided, which may be manufactured using relaxed groundrules, to provide low cost, high yield devices.Temperature dependence of threshold voltage may also be eliminated by providing a semiconductor gate contact which neutralizes the effect of substrate contact potential.
    Type: Grant
    Filed: June 22, 1989
    Date of Patent: January 8, 1991
    Assignee: Thunderbird Technologies, Inc.
    Inventor: Albert W. Vinal