Patents by Inventor William H. Herndon

William H. Herndon has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5506541
    Abstract: A bias generation and distribution system in which bias potentials are generated at one main location within a logic circuit and then distributed throughout the logic circuit to MOS load devices, MOS load networks, other bias voltage conversion centers, and logic circuits is disclosed. The system generates a first bias voltage that provides a temperature compensated voltage that is utilized to bias MOS load devices and parallel MOS load networks. The first bias voltage generator includes either a reference MOS load device or a reference parallel MOS load network which determines the value of the first bias voltage. The reference MOS load network includes a switching network responsive to a first set of control signals. The first set of control signals may be adjusted to vary the value of the first bias voltage to compensate for process variations. The first bias voltage is distributed to either remote single load MOS devices or to remote parallel MOS load networks.
    Type: Grant
    Filed: April 3, 1995
    Date of Patent: April 9, 1996
    Assignee: MicroUnity Systems Engineering, Inc.
    Inventor: William H. Herndon
  • Patent number: 5499445
    Abstract: A multi-layered package is disclosed that employs novel shielding techniques to improve high frequency performance of the package. Shield vias are placed near conductive vias to create a two-wire transmission line with controllable characteristic impedance. Controlled transmission line impedance reduces signal reflection due to line impedance variations and ground bounce due to inductive coupling. Opposite polarity shielding technique is introduced in vertical as well as horizontal directions to reduce capacitive coupling of noise between signals and provide immunity against differential power supply noise. Signal layers disposed half way between floating shield planes provided immunity against non-common mode noise coupling. For integrated circuits with varying types of signals (e.g. CMOS and TTL and ECL type signals), the package creates electrically isolated zones to drastically reduce noise coupling between the circuits with different signal types.
    Type: Grant
    Filed: April 13, 1994
    Date of Patent: March 19, 1996
    Assignee: Intergraph Corporation
    Inventors: Steven R. Boyle, Robert J. Proebsting, William H. Herndon
  • Patent number: 5338970
    Abstract: A multi-layered package is disclosed that employs novel shielding techniques to improve high frequency performance of the package. Shield vias are placed near conductive vias to create a two-wire transmission line with controllable characteristic impedance. Controlled transmission line impedance reduces signal reflection due to line impedance variations and ground bounce due to inductive coupling. Opposite polarity shielding technique is introduced in vertical as well as horizontal directions to reduce capacitive coupling of noise between signals and provide immunity against differential power supply noise. Signal layers disposed half way between floating shield planes provided immunity against non-common mode noise coupling. For integrated circuits with varying types of signals (e.g. CMOS and TTL and ECL type signals), the package creates electrically isolated zones to drastically reduce noise coupling between the circuits with different signal types.
    Type: Grant
    Filed: March 24, 1993
    Date of Patent: August 16, 1994
    Assignee: Intergraph Corporation
    Inventors: Steven R. Boyle, Robert J. Proebsting, William H. Herndon
  • Patent number: 4868421
    Abstract: To reduce the total power dissipation of an emitter-follower driver or logic circuit, an MOS transistor is connected between an output terminal of the circuit and a suitable voltage source. The MOS transistor is operated in opposite phase to an emitter follower bipolar transistor that provides driving current to the output terminal, so that one is on while the other is off. The MOS transistor limits the current in the emitter follower transistor in either state of the circuit, thus reducing power dissipation. It also provides for a larger transient driving current to the output terminal, thus increasing the switching speed of the circuit.
    Type: Grant
    Filed: February 24, 1987
    Date of Patent: September 19, 1989
    Assignee: Fairchild Semiconductor Corporation
    Inventors: William H. Herndon, Robert J. Proebsting
  • Patent number: 4857772
    Abstract: A decoder incorporates the advantageous features of both bipolar and BICMOS decoding circuits through the use of BIPMOS technology. PMOS gating transistors are used to control the operation of bipolar output transistors. It is only necessary to operate the PMOS transistors with relatively small drain voltage variations, since the bipolar transistors are sensitive to such small variations. Further, transient signals are referenced to one power supply voltage only, to thereby make the logic swing and performance characteristics of the decoder independent of power supply voltage variations. Therefore it becomes possible to use PMOS transistors that have smaller voltage requirements than conventional CMOS circuits.
    Type: Grant
    Filed: April 27, 1987
    Date of Patent: August 15, 1989
    Assignee: Fairchild Semiconductor Corporation
    Inventor: William H. Herndon
  • Patent number: 4713560
    Abstract: There is disclosed herein an ECL gate using switchable load impedance means to allow the gate to be placed in a low power-consumption mode while preserving the logic state existing at the outputs of the gate at the time it is switched into the low-power mode. N-channel or P-channel MOS transistors are used as the switchable load impedances. The gates of these transistors are coupled to a MODE control signal which causes the MOS transistors to switch between high-impedance and low-impedance states. Another MOS transistor having its gate coupled to the same MODE control signal is used as the current source for the bias current to the conventional ECL current mirror. When low-power mode operation is desired, all the MOS transistors are switched to their high-impedance states. This reduces the bias current flowing through the ECL gate, thereby reducing its power consumption.
    Type: Grant
    Filed: June 5, 1986
    Date of Patent: December 15, 1987
    Assignee: Fairchild Semiconductor Corporation
    Inventor: William H. Herndon
  • Patent number: 4627034
    Abstract: The present invention utilizes the power available for application to a static RAM cell in a manner which provides efficient use of the power so that greater standby power may be applied to the static RAM to increase the memory speed. The current required to maintain the memory cell in a preset state flows from the U.sub.cc source through a row of parallel memory cells and through a common bias supply and various peripheral circuits, such as decoders. A shunt voltage regulator controls the dependence of the common bias supply voltage on current fluctuations caused by addressing and deaddressing the memory cells. The invention includes an isolation device for isolating a particular row of memory cells when it is addressed without disturbing the bias on other memory cell rows. Similarly, the reference voltages of each of the peripheral circuits can be made independent of the common bias supply voltage and independent of the other peripheral circuits by the use of a local voltage regulator on each peripheral.
    Type: Grant
    Filed: November 9, 1984
    Date of Patent: December 2, 1986
    Assignee: Fairchild Camera and Instrument Corporation
    Inventor: William H. Herndon
  • Patent number: 4622575
    Abstract: A static bipolar random access memory cell includes first and second transistors formed in epitaxial silicon pockets 41 and 42 in a substrate. The collectors 19 and 19' and bases 15 and 15' of the transistors are interconnected with polycrystalline silicon 21 doped to match the conductivity types of the regions contacted. Undesired PN junctions 40 and 40' created thereby are shorted using an overlying layer of a metal silicide 25. In a region overlying the N conductivity type polycrystalline silicon 23 or 23', the metal silicide is removed and a PH junction 37 or 37' created by depositing P conductivity type polycrystalline silicon 35c or 35c'. If desired additional P type polycrystalline silicon 35a and 35b may be deposited across the surface of the epitaxial layer where the base regions of the two transistors are formed to reduce the base series resistance.
    Type: Grant
    Filed: September 4, 1984
    Date of Patent: November 11, 1986
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Madhukar B. Vora, William H. Herndon
  • Patent number: 4488350
    Abstract: A static bipolar random access memory cell includes first and second transistors formed in epitaxial silicon pockets 41 and 42 in a substrate. The collectors 19 and 19' and bases 15 and 15' of the transistors are interconnected with polycrystalline silicon 21 doped to match the conductivity types of the regions contacted. Undesired PN junctions 40 and 40' created thereby are shorted using an overlying layer of a metal silicide 25. In a region overlying the N conductivity type polycrystalline silicon 23 or 23', the metal silicide is removed and a PN junction 37 or 37' created by depositing P conductivity type polycrystalline silicon 35c or 35c'. If desired additional P type polycrystalline silicon 35a and 35b may be deposited across the surface of the epitaxial layer where the base regions of the two transistors are formed to reduce the base series resistance.
    Type: Grant
    Filed: October 27, 1981
    Date of Patent: December 18, 1984
    Assignee: Fairchild Camera & Instrument Corp.
    Inventors: Madhukar B. Vora, William H. Herndon
  • Patent number: 4488263
    Abstract: A current bypass for a microelectric memory, such as a static RAM, diverts word line discharge current such that the current does not flow through the memory cells of a selected word line or along an upper word line conductor. In a first embodiment, the bypass comprises a resistor R1 (R2) and a diode D10 (D20) in series and coupled between an upper word line conductor 50 and word line discharge current source V.sub.CC, and a lower word line conductor 51 and word line discharge current sink 42. In another embodiment of the invention, a transistor Q10 (Q20) is used in lieu of the diode. By bypassing current from the upper word line conductor and word line memory cells, metal migration is eliminated and narrower metal lines may be used to form the word lines. By eliminating a flow of steady state discharge current through the memory cells, memory cell current saturation is eliminated.
    Type: Grant
    Filed: March 29, 1982
    Date of Patent: December 11, 1984
    Assignee: Fairchild Camera & Instrument Corp.
    Inventors: William H. Herndon, Jonathan J. Stinehelfer
  • Patent number: 4484311
    Abstract: A circuit for use in controlling a memory cell coupled to a word line W and to first and second bit lines B1 and B2 includes an enabling flip-flop 20 having set terminal S connected to a source of enabling signals and a reset terminal R connected to an OR gate 22; a word line addressing circuit 25 connected to the output of the enabling flip-flop 20 and to the word line W, and having a terminal ADDR for receiving address information; first and second read/write circuits 29 and 30 connected to corresponding first and second bit lines B1 and B2, respectively, each of the read/write circuits 29 and 30 including a control node WRC and an output node SADO; a logic gate 22 having an output coupled to the reset terminal and having input nodes SADO 0 and SADO 1 connected to the corresponding output nodes of the read/write circuits 29 and 30, and an output flip-flop 33 connected the output nodes SADO 0 and SADO 1 of the read/write circuits 29 and 30.
    Type: Grant
    Filed: June 10, 1982
    Date of Patent: November 20, 1984
    Assignee: Fairchild Camera & Instrument Crop.
    Inventor: William H. Herndon
  • Patent number: 4442509
    Abstract: A bit line powered translinear memory cell includes a pair of NPN transistors Q101 and Q102 having cross-coupled bases and collectors. Diode loads D101 and D102 couple the NPN transistors Q101 and Q102 to the bit lines 301 and 302. The emitters of the two transistors Q101 and Q102 are coupled together and to a word line 103. Cell parasitic capacitances C101 and C102 are used to maintain data in nonaddressed memory cells during reading of other cells coupled to the same word line 103.
    Type: Grant
    Filed: October 27, 1981
    Date of Patent: April 10, 1984
    Assignee: Fairchild Camera & Instrument Corporation
    Inventor: William H. Herndon
  • Patent number: 4257059
    Abstract: A semiconductor memory cell comprising first and second bipolar cell transistors cross-coupled by the inverse transistor action of third and fourth bipolar transistors. Each cross-coupling transistor is formed by a single emitter diffusion in an existing common base region of one cell transistor, above a common buried collector region of the same cell transistor. The use of cross-coupling transistors eliminates the need for a direct ohmic connection to the buried layer collector, thereby simplifying layout and reducing memory cell size.
    Type: Grant
    Filed: December 20, 1978
    Date of Patent: March 17, 1981
    Assignee: Fairchild Camera and Instrument Corp.
    Inventor: William H. Herndon
  • Patent number: 4104734
    Abstract: Circuitry that senses a drop in the power supply voltage and turns off bias voltages in the proper sequence to prevent further writing into the cells of a random access memory while permitting the cells to remain in a low supply voltage standby to retain their stored data.
    Type: Grant
    Filed: June 30, 1977
    Date of Patent: August 1, 1978
    Assignee: Fairchild Camera and Instrument Corporation
    Inventor: William H. Herndon
  • Patent number: 4032902
    Abstract: An improved memory cell comprising a word line, a pair of bit lines, a pair of load impedances, and a pair of switching transistors. The pair of switching transistors each include an emitter coupled to a respective one of the bit lines, a base coupled to a respective one of the load impedances, and a collector coupled to the base of the other switching transistor. The pair of load impedances may include a pair of transistors each having an emitter coupled to the word line, a base coupled to a respective one of the emitters of the pair of switching transistors, and a collector coupled to a respective one of the bases of the switching transistors.
    Type: Grant
    Filed: October 30, 1975
    Date of Patent: June 28, 1977
    Assignee: Fairchild Camera and Instrument Corporation
    Inventor: William H. Herndon