Patents Examined by Benjamin D. Driscoll
  • Patent number: 5696729
    Abstract: A power conserving circuit configuration is presented which reduces the power supplied to the input/output pins in the initial input circuit in a synchronous semiconductor device. The circuit reduces the power to the input/output pins in the initial input circuit during the standby mode and/or readout mode, and restores the power to the initial input circuit, when an input signal is entered in an external disabling pin which generates an output disabling signal, which makes the output signal from the input/output pin to be nullified and causes the power to be restored in the synchronous semiconductor device.
    Type: Grant
    Filed: December 15, 1994
    Date of Patent: December 9, 1997
    Assignee: NEC Corporation
    Inventor: Mamoru Kitamura
  • Patent number: 5696453
    Abstract: The invention provides a logic circuit including (a) a load element having ends one of which is electrically connected to a first terminal of a voltage source, and the other to an output terminal, (b) a first enhancement mode FET including a drain electrode electrically connected to the output terminal, a gate electrode connected to an input terminal, and a source electrode connected to a junction, (c) a second enhancement mode FET including a drain electrode electrically connected to the first terminal, a gate electrode connected to the output terminal, and a source electrode connected to the junction, and (d) a depletion mode FET including a drain electrode electrically connected to the junction, a gate electrode connected to a control terminal, and a source electrode connected to a second terminal of the voltage source. The logic circuit ensures sufficient noise margin to temperature variation, resulting in a lower supply voltage.
    Type: Grant
    Filed: November 20, 1995
    Date of Patent: December 9, 1997
    Assignee: NEC Corporation
    Inventor: Tadashi Maeda
  • Patent number: 5694060
    Abstract: A CMOS differential twisted-pair driver which utilizes CMOS switches and current sources advantageously. No alternative power supply is required, the switches do not have to be low impedance and the device is low power. The preferred embodiment driver further limits signal overshoot and common mode energy. The signal transmission facility is bi-directional so an off state is provided. It is doubly terminated to provide for symmetry, improved bandwidth and reduces reflective signal noise. The double termination also provides for faster rise and fall times which reduces the systems sensitivity to receiver offset.
    Type: Grant
    Filed: December 13, 1994
    Date of Patent: December 2, 1997
    Assignee: Apple Computer, Inc.
    Inventors: Roger Van Brunt, Florin Oprescu
  • Patent number: 5694058
    Abstract: In order to increase routing flexibility for the output signals of logic modules in programmable logic array integrated circuit devices, the output signal of each logic module can be swapped with the output signal of another logic module by a first level of signal swapping circuitry. The output signals of the first level of swapping circuitry can be further swapped with output signals of other first level swapping circuits by a second level of signal swapping circuitry to provide still more routing flexibility for the logic module output signals.
    Type: Grant
    Filed: March 20, 1996
    Date of Patent: December 2, 1997
    Assignee: Altera Corporation
    Inventors: Srinivas T. Reddy, Chiakang Sung, Bonnie I-Keh Wang
  • Patent number: 5691655
    Abstract: A driver circuit is provided which unconditionally discharges a bus conductor during clock cycles in which the driver circuit is transmitting a value. The unconditional discharge occurs during a first drive phase of the logic drive state. During a second drive phase, the driver circuit either charges or continues to discharge the conductor based on the data value being transmitted. Since the conductors are transitioning in the same direction at approximately the same rate, line to line coupling is virtually non-existent during the first drive phase. By partially discharging bus conductors during the first drive phase, transition speed is increased to the point at which a receiving circuit senses the transmitted value. Effectively, the line-to-line coupling which would have occurred during the first drive phase is endured during the second drive phase, when certain conductors may be recharged.
    Type: Grant
    Filed: November 27, 1995
    Date of Patent: November 25, 1997
    Assignee: Advanced Micro Devices, Inc.
    Inventor: Joseph P. Geisler
  • Patent number: 5684410
    Abstract: An output buffer circuit for preconditioning an output signal at an output node so as to provide a higher speed of operation and less ground bounce noise includes an output buffer stage, a precondition feedback circuit, an output predriver, an output tristate control circuit, and an output state retention circuit. The output pre-driver with input equalization, which is also part of precondition control, combined with the output buffer stage designed with its threshold voltage matching component's input and output threshold voltage such that the output feedback, which bring the output and the input nodes of the output buffer stage together, will drive the output level to the threshold point enabled by the precondition signals before the data input signals arrive. The output buffer noise can be reduced by slowly driving output level to the output threshold point about three to four nanoseconds earlier than the data input signals arrive.
    Type: Grant
    Filed: July 3, 1995
    Date of Patent: November 4, 1997
    Inventor: Frank Tzen-Wen Guo
  • Patent number: 5684416
    Abstract: A semiconductor integrated circuit device has a differential logic circuit formed by multi-stage series-gating logic circuits each composed of bipolar transistors whose emitters are connected in common and level shift circuits each for shifting a level of an input signal that is inputted from the outside in correspondence to one of the stage logic circuits of the differential logic circuit, and for supplying the level-shifted input signal to the base of one of the bipolar transistors of the corresponding logic circuit. In particular, a potential difference between the level-shifted signals inputted to the bases of the bipolar transistors of each of the stage logic circuits is determined, as a level shift rate, to be lower than a built-in potential between the base and emitter of each of the bipolar transistors thereof. The semiconductor integrated circuit device is operative on a lower supply voltage, without significantly degrading the functions and performance thereof.
    Type: Grant
    Filed: April 18, 1995
    Date of Patent: November 4, 1997
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Tadahiro Kuroda
  • Patent number: 5682108
    Abstract: A high speed level translator is disclosed in which an ECL differential input signal is applied to a differential input amplifier, amplified, and converted to a single ended intermediate signal. An inverter circuit receives the intermediate signal and outputs a signal indicative of the polarity of the ECL differential input signal. The differential amplifier is biased with a current source which varies the bias current according to fluctuations in the supply voltage such that the operating point of the differential amplifier is automatically adjusted to compensate for variations in the supply voltage. Adjusting the bias current in such a manner allows for a reduction in power dissipation over conventional level translators. Further, since the differential amplifier is configured to provide a single ended intermediate signal, a current mirror is not required to be connected between the differential amplifier and the inverter.
    Type: Grant
    Filed: May 17, 1995
    Date of Patent: October 28, 1997
    Assignee: Integrated Device Technology, Inc.
    Inventor: Sung-Ki Min
  • Patent number: 5682107
    Abstract: An FPGA architecture offers logic elements with direct connection to neighboring logic elements and indirect connection through a routing matrix. A logic element and a portion of the routing matrix are formed as part of a tile, and tiles are joined to form arrays of selectable size. The routing matrix includes routing lines which connect just from one tile to the next and routing lines which extend longer distances through several tiles or through the entire chip. This combination is achieved by the formation of individual tiles, all of which are identical.
    Type: Grant
    Filed: March 19, 1996
    Date of Patent: October 28, 1997
    Assignee: Xilinx, Inc.
    Inventors: Danesh Tavana, Wilson K. Yee, Victor A. Holen
  • Patent number: 5680065
    Abstract: An improved SCSI bus driving circuit is capable of speedily transmitting a data irrespective of the length of a small computer system interface bus cable or the number of targets connected to a host computer. The circuit includes an output buffer for buffering the output signal of a data output terminal of a host computer; and an enabling circuit for detecting the output signal of the output buffer using a logic threshold voltage of a logic gate and logically combining the signal detected and the output signal of a mode selection terminal outputted from the host computer.
    Type: Grant
    Filed: October 20, 1995
    Date of Patent: October 21, 1997
    Assignee: LG Semicon Co., Ltd.
    Inventor: Hyun Ju Park
  • Patent number: 5675264
    Abstract: A differential circuit configuration for generating an inverted signal and a non-inverted signal of an original signal is presented. The waveforms of the output signals are highly synchronous and precise owing to the circuit design which provides matched gate-to-source voltage vs drain-to-source current to produce output trace matching in the output voltage traces of a pair of pull-up transistors with a pair of pull-down transistors. The circuit configuration does not require adjustable capacitors or driving circuits, and is therefore suitable for use in advanced compact devices.
    Type: Grant
    Filed: December 28, 1994
    Date of Patent: October 7, 1997
    Assignee: NEC Corporation
    Inventor: Makoto Yoshida
  • Patent number: 5675262
    Abstract: A fast carry-out scheme in a field programmable logic array. The configurable logic blocks (CLBs) are arranged in columns. The carry-out signals are routed from the bottom CLB of a column to the top CLB of that column. The carry-out from the top-most CLB is then multiplexed onto a clock line that is normally used to conduct clocking signals to the CLBs. Instead of conducting clocking signals, the existing clock line is now used to route the carry-out signal onto a vertical longline spanning the entire height of the column. Eventually, the carry-out signal is routed from the longline to its destination CLB of the adjacent column via local interconnect resources.
    Type: Grant
    Filed: October 26, 1995
    Date of Patent: October 7, 1997
    Assignee: Xilinx, Inc.
    Inventors: Khue Duong, Stephen M. Trimberger, Bernard J. New
  • Patent number: 5672984
    Abstract: A programmable logic array comprises a PLA area having a plurality of banks wherein each of the bank has an array of a discharge typed logic circuit for decoding a micro-code, a command code is inputted to each bank every cycle for executing a predetermined command, and each bank outputs bank selection data for determining by which bank a command of a next cycle be decoded at the previous cycle, and a control circuit for selecting one bank for decoding the command code of the next cycle from the plurality of banks based on the bank selection data of each bank in the previous cycle, and for sending a command code to only the selected one bank to perform discharge of a discharge typed logic circuit, thereby stopping operations of other banks.
    Type: Grant
    Filed: May 29, 1996
    Date of Patent: September 30, 1997
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazumasa Ando, Syoji Horie
  • Patent number: 5670893
    Abstract: The invention provides a BiCMOS logic gate circuitry comprising: input and output terminals: an output driving section including two bipolar transistors in the form of totem pole connection between a high voltage line and a low voltage line in which an intermediate point between the two bipolar transistors is connected to the output terminal; a base driving section including a plurality of MOS transistors and being connected to an input terminal for receiving an input signal and connected to bases of the bipolar transistors; and a base clamping section including at least one clamping circuit being connected to at least one of the bipolar transistors through its base for restricting a base potential of the at least one bipolar transistor in the vicinity of the same potential as a base-emitter forward bias at which the bipolar transistor turns ON so as to reduce the necessary time for charging a parasitic capacitance of the base of the at least one bipolar transistor.
    Type: Grant
    Filed: September 26, 1994
    Date of Patent: September 23, 1997
    Assignee: NEC Corporation
    Inventor: Hitoshi Okamura
  • Patent number: 5668483
    Abstract: A CMOS buffer circuit having a trip point which is insensitive to variations in temperature, supply voltages and manufacturing processes. The circuit output stage has three series-connected MOS transistors including an N channel pull-down transistor connected between the buffer output and the circuit common, a first P channel pull-up transistor connected to a positive supply voltage and a second P channel pull-up transistor connected between the first P channel transistor and the buffer output. The gates of the first P channel transistor and the N channel transistor are connected together to form the buffer input. An N channel reference transistor is used to generate a reference current which is mirrored into the output stage by a third P channel transistor which is connected to the second P channel transistor of the output stage so as to form a current mirror.
    Type: Grant
    Filed: June 21, 1995
    Date of Patent: September 16, 1997
    Assignee: Micron Quantum Devices, Inc.
    Inventor: Frankie F. Roohparvar
  • Patent number: 5668484
    Abstract: A clock signal distribution circuit of a tree structure having a plurality of buffers arranged in a plurality of hierarchical stages includes short-circuit wirings for short-circuiting output terminals of the buffers at each stage of the plurality of hierarchical stages. Each of the plurality of buffers is formed by a single inverter or a multi-stage inverter wherein an input stage inverter and an output stage inverter are connected in series. The output stage inverter has a size larger than that of the input stage inverter. The clock signal distribution circuit thus constructed can reduce clock skew and distribute a high frequency clock signal having sharp rise and fall characteristics to a plurality of registers.
    Type: Grant
    Filed: September 16, 1994
    Date of Patent: September 16, 1997
    Assignee: NEC Corporation
    Inventor: Masahiro Nomura
  • Patent number: 5666068
    Abstract: A GTL input receiver for receiving differential GTL signals and for generating a CMOS output at a single-ended output terminal includes a comparator circuit, a current-to-voltage converter circuit, and an inverter. The comparator is formed of a first primary current steering device and a second primary current steering device. Auxiliary current steering devices are coupled to the first and second primary current steering devices for adding hysteresis by dynamically changing the ratio of the currents flowing through the first and second primary current source devices. The input receiver also includes a control circuit for selectively enabling and disabling the secondary current steering devices. As a result, the GTL input receiver has a hysteresis in the range of 50 mV to 200 mV and higher.
    Type: Grant
    Filed: November 3, 1995
    Date of Patent: September 9, 1997
    Assignee: VLSI Technology, Inc.
    Inventor: Gregory E. Ehmann
  • Patent number: 5661417
    Abstract: A purpose of this invention is to realize a bus system of high speed and low power consumption type applying precharge. A precharge signal input line (4), a power source potential (V.sub.DD), and a bus (1) are connected to a gate electrode, a drain region, and a source region of a first MOS transistor (MNP), the power source potential (V.sub.DD), a node (N1), and the bus (1) are connected to a gate electrode, a drain region, and a source region of a second MOS transistor (MN1), and the precharge signal input line (4) through an inverter (3), the power source potential (V.sub.DD), and the node (N1) are connected to a gate electrode, a source region, and a drain region of a third MOS transistor (MP1), respectively. In precharge period (PC=H), the potential of the bus (BUS) rises gradually, and the both transistors (MNP, MN1) are turned off. In EVL period (PC=L), when data is output from a register (6), the potential of the bus (BUS) drops, and the second MOS transistor (MN1) is turned on.
    Type: Grant
    Filed: August 31, 1995
    Date of Patent: August 26, 1997
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Harufusa Kondoh
  • Patent number: 5661412
    Abstract: Critical programmed reliability of a metal-to-metal amorphous silicon antifuse is a function of programming current, operating current and total programming time. The time required to program a field programmable gate array is reduced by classifying antifuses to be programmed into three or more classes according to the amount of programming time required to achieve critical programmed reliability under programming current and operating current conditions. Each of these classes of antifuses is programmed with near the minimum programming time required to program every antifuse in the class to critical reliability. In this way, large numbers of antifuses are not programmed with significantly greater amounts of programming time than are actually required to program them to critical reliability. The time required to program the field programmable gate array is therefore reduced. Techniques for obtaining critical reliability data used in classifying antifuses are also disclosed.
    Type: Grant
    Filed: October 10, 1995
    Date of Patent: August 26, 1997
    Assignee: QuickLogic Corporation
    Inventors: Amarpreet S. Chawla, Richard J. Wong, Andrew K. Chan
  • Patent number: 5661413
    Abstract: A data operating circuit in which a logic combinatorial circuit and a transfer gate are built, and a controller for controlling the data operating circuit are disposed. The controller includes a drive unit for applying a drive signal to a gate of an N-channel transistor included in the transfer gate, and a control unit for controlling the operation of the drive unit. The data operating circuit is supplied with a first voltage via a first power supply line, and the controller is supplied with a second voltage that has a higher voltage value than the first voltage. A signal line for transferring an output signal of the data operating circuit to the controller is provided with a level converter for increasing the level of the output signal of the data operating circuit to a level required for the operation of the control unit. As a result, a timing skew of the transfer gate can be retained small while minimizing power consumption of the data operating circuit.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: August 26, 1997
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yasuhiro Tomita, Toshiyuki Shono, Hirokazu Yonezawa