Converging With Plural Inputs And Single Output Patents (Class 327/407)
  • Patent number: 6466073
    Abstract: Clock generating circuitry includes a frequency dividing circuit for dividing the frequency of an input clock by each of a plurality of predetermined frequency dividing ratios which differ from each other to generate a plurality of frequency-divided clocks such that a frequency-divided clock generated with the smallest frequency dividing ratio, i.e., a frequency-divided clock having the highest frequency, is slightly delayed against all of the other generated frequency-divided clocks. When changing the frequency of an output clock, a multiplexer switches from a previously selected one of the plurality of generated frequency-divided clocks to a desired clock in responsive to a control signal. The desired frequency-divided clock is then furnished as the output clock.
    Type: Grant
    Filed: September 27, 2000
    Date of Patent: October 15, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yoshio Yukinari, Kouichi Ishimi
  • Patent number: 6456146
    Abstract: A system and method are presented for multiplexing two or more clocking signals. In one embodiment, a first enable circuit is provided that receives a select signal, a first clocking signal, and an enable signal from a second enable circuit. The first enable circuit generates an enable signal in response to these signals. For example, the first enable circuit could include a flip-flop clocked by the first clocking signal that generates the enable signal when the first clocking signal has been selected (based on the select signal), when the enable signal from the second enable circuit is deasserted and the first clocking signal has reached a falling edge. The enable signal can then be used to filter the first clocking signal (e.g., using an AND gate) to provide the first clocking signal as an output signal. Using the system and method of the present invention, glitches and spikes seen when multiplexing two or more clocking signals can be avoided.
    Type: Grant
    Filed: December 28, 2000
    Date of Patent: September 24, 2002
    Assignee: Intel Corp.
    Inventors: Nathanel Darmon, Aviad J. Wertheimer
  • Patent number: 6456147
    Abstract: An output interface circuit realizes a fast and stable interface operation without any chip-size increase even if the external supply voltage varies within a specific range (e.g., from 5 V to 3.3 V or from 5 V to 2 V). The output interface circuit comprises a first and a second output buffer circuit for receiving an output signal of an internal circuit, and an output-level adjusting circuit for receiving the output signal of the second output buffer circuit, for level-adjusting the output signal, and for outputting the level-adjusted output signal to an external output terminal. The first or second output buffer circuit outputs a signal based on the value of an external supply voltage.
    Type: Grant
    Filed: August 27, 2001
    Date of Patent: September 24, 2002
    Assignee: NEC Corporation
    Inventor: Hiroyuki Kohamada
  • Patent number: 6452436
    Abstract: An improved crossover circuit for a V/I source includes a selector and a measurement circuit. The selector and measurement circuit both receive error signals indicative of differences between programmed and actual values of output voltage and current of the V/I source. In response to occurrences of predetermined events among the error signals, the measurement circuit activates the selector to pass one of the error signals to a control circuit for establishing a feedback loop. Different events cause different error signals to be selected, and hence cause different feedback loops of the V/I source to be activated. The improved crossover circuit provides increased control over the selection of feedback mode, and enhances the ability to individually optimize dynamic behavior of different feedback modes.
    Type: Grant
    Filed: April 12, 2001
    Date of Patent: September 17, 2002
    Assignee: Teradyne, Inc.
    Inventor: David G. Leip
  • Patent number: 6452423
    Abstract: A circuit for avoiding contention in such circuits as an n-to-1 transmission gate multiplexer in a high performance microprocessor or integrated circuit utilizes a same-gate symmetrical design and reverse polarity control signals to overcome disadvantages of prior circuits while accommodating increasing circuit speeds. The circuit employs all NAND gates on the select lines controlling multiplexer transmission gates rather than NAND gates and a NOR gate. The design may also be implemented using AND gates. In addition to using a NAND gate where prior designs use a NOR gate, the polarity of the flip-flop output which drives the additional NAND gate is inverted, and the polarity of the input to the transmission gate driven by the additional NAND gate is also inverted. The circuit thus provides a symmetric design using the same NAND logic gates on all select lines while preserving functionality of the n-to-1 multiplexer.
    Type: Grant
    Filed: July 24, 2000
    Date of Patent: September 17, 2002
    Assignee: Sun Microsystems, Inc.
    Inventors: Ashutosh Das, Sridhar Narayanan
  • Patent number: 6441668
    Abstract: A device includes a first input pin, a second input pin, a differential signal generator, and a differential receiver. The first input pin is adapted to receive a first signal. The second input pin is adapted to receive a second signal. The differential signal generator is coupled to the first and second input pins and adapted to receive an enable signal. The differential signal generator is adapted to isolate the second input pin and generate an internal signal based on an inversion of the first signal in response to the enable signal being asserted. The differential receiver has a first input terminal and a second input terminal. The differential receiver is adapted to receive the first signal at the first input terminal and one of the second signal and the internal signal at the second input terminal and generate a differential output signal. A method for generating a differential signal is provided. A first input signal is received at a first input pin of a device. An enable signal is received.
    Type: Grant
    Filed: April 6, 1999
    Date of Patent: August 27, 2002
    Assignee: Micron Technology, Inc.
    Inventor: James E. Miller
  • Patent number: 6437632
    Abstract: A signal selection circuit, which has a resistant characteristic to crosstalk noise among signals and can output inputted signals without having the deterioration of the duty ratio of the inputted signals, is provided. The signal selection circuit, in which one signal is selected from plural inputted signals and the selected one signal is outputted, provides plural select circuit blocks, which are disposed in a matrix state, for choosing whether each inputted signal is made to transmit or cut off, and input lines, which are wired to one direction, for making the plural inputted signals input to the plural select circuit blocks, and output lines, which are wired to the cross direction to the input lines, for making outputted signals from the plural select circuit blocks output. And the input lines and the output lines are disposed between wiring biased by a constant voltage. And the plural select circuit blocks are surrounded with wiring biased by a constant voltage.
    Type: Grant
    Filed: May 30, 2000
    Date of Patent: August 20, 2002
    Assignee: NEC Corporation
    Inventor: Yuki Goko
  • Patent number: 6417709
    Abstract: A duty cycle controller provides a uniform 50% duty cycle in a 2:1 digital multiplexer without an upper operating frequency limit. The multiplexer uses a comparator to generate interleaving signals by comparing a clock signal to a comparator set point. A feedback loop includes a bandpass filter, a power detector and an integrator, connected in series between the multiplexer output and the comparator. The bandpass filter passes components of the multiplexed output signal with a frequency substantially equal to the main clock frequency of the multiplexer. Signal components at that frequency are a second harmonic of the fundamental frequency of the multiplexed signal and therefore will not be present in the multiplexed signal if its duty cycle is exactly 50%. The power level of those frequency components is integrated over a suitable time period and the integrated signal is used to adjust the set point of the comparator.
    Type: Grant
    Filed: April 30, 1998
    Date of Patent: July 9, 2002
    Assignee: Lucent Technologies Inc.
    Inventor: Osamu Mizuhara
  • Patent number: 6417721
    Abstract: An inventive integrated circuit die includes a bond pad connected to first and second input buffers in the die through laser fuses. In one operating configuration of the die, the die uses the first input buffer but does not use the second input buffer, so the laser fuse between the bond pad and the second input buffer is blown. In another operating configuration of the die, the die uses the second input buffer but does not use the first input buffer, so the laser fuse between the bond pad and the first input buffer is blown. As a result, the capacitive load on the bond pad is similar to the capacitive load on similar bond pads in the die connected to only one input buffer in the die. Thus, signals propagate into all the bond pads at about the same improved speed.
    Type: Grant
    Filed: June 11, 2001
    Date of Patent: July 9, 2002
    Assignee: Micron Technology, Inc.
    Inventor: Joseph C. Sher
  • Patent number: 6417717
    Abstract: A unique hierarchical multiplexer is employed to multiplex signals read out from analog array elements one at a time to an output. In an embodiment of the invention, the multiplexer switching elements, i.e., switches, are arranged in groups in a hierarchical, i.e., tree, configuration. In the tree configuration for a given analog array size, output capacitance is significantly reduced because each analog array element and its associated buffer amplifier drive fewer switches than in other configurations. The lower capacitance reduces any resulting FPN and the resulting lower analog array element and buffer amplifier drive current reduces power dissipation. The reduced capacitance also decreases the transient settling time interval.
    Type: Grant
    Filed: December 31, 1998
    Date of Patent: July 9, 2002
    Assignee: Agere Systems Guardian Corp.
    Inventor: Marc J. Loinaz
  • Patent number: 6417718
    Abstract: An internal input voltage generating/external output voltage generating circuit is provided within a semiconductor device, a voltage on a pad corresponding to a supply pin terminal is detected to specify the inserted orientation of the semiconductor device based on the detection result and apply a correct voltage to a chip internal circuit. According to the specified direction, one of a plurality of pin terminals located in rotation or line-symmetry is selected to couple the selected terminal to the chip internal circuit. Accordingly, a semiconductor device can be implemented that is never damaged and operates normally even if the device is mounted on a circuit board in any possible orientation which the device can take upon board mounting.
    Type: Grant
    Filed: June 22, 2000
    Date of Patent: July 9, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Akiko Ota
  • Patent number: 6414528
    Abstract: A clock generation circuit that generates multi-phase output clock signals which immediately follow any change in the period of an input clock signal. This clock generation circuit comprises a voltage-controlled oscillator (14) that generates an output signal having a frequency that varies in response to a control voltage; a phase comparator (11) that compares the phase of the input clock signal and the phase of the output signal of the voltage-controlled oscillator, to detect the phase difference therebetween; control voltage generation circuits (12, 13) that generate a control voltage corresponding to that phase difference; and a variable delay circuit (15) that generates multi-phase output clock signals by delaying the input clock signal in accordance with the control voltage.
    Type: Grant
    Filed: December 22, 2000
    Date of Patent: July 2, 2002
    Assignee: Seiko Epson Corporation
    Inventor: Toshimasa Usui
  • Patent number: 6411135
    Abstract: A clock signal switching circuit that switches between two clock signals having a phase difference. The clock signal switching circuit includes a first selector that selects one of the clock signals according to the level of a selection signal, a second selector that selects one of first and second control signals according to the level of the selection signal. The level of the first and second control signals are changed in response to an original signal and the first or the second clock signal. A gate circuit generates the output signal from the first and second selectors wherein the level of the selection signal is changed in response to the original signal after the levels of both of the first and second control signals have changed.
    Type: Grant
    Filed: May 15, 2001
    Date of Patent: June 25, 2002
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Eiji Komoto
  • Publication number: 20020075058
    Abstract: A method for preventing redundant events from toggling the core logic during scan data shifting mode is provided. A logic element is controlled by SEL. During scan data shifting mode, no toggled data will interfere with the core logic because the logic element is shut off. Only the scan path (SI-SO-SI) continues toggling. Therefore, redundant events are prevented from toggling the core logic. Therefore the simulation time is reduced and the verification flow is sped up. Additionally, the power consumption during testing is significantly reduced.
    Type: Application
    Filed: December 19, 2000
    Publication date: June 20, 2002
    Inventors: Chi-Yi Hwang, Shao-I Chen, Cheng-I Huang, Kun-Cheng Wu
  • Patent number: 6407614
    Abstract: The semiconductor integrated switching circuit S1 employed in a dual-band mobile phone comprises the first through fourth field effect transistor 1, 2, 3, 4 by which electrical connection between either of the first through fourth input/output terminal 22 through 25 and the common input-output terminal 21 are controlled, the fifth field effect transistor 5 which becomes conducting with the second field effect transistor 2, and the series resonance circuit 51 having a resonance frequency equals to a frequency of higher harmonic of the signal passing through the second field effect transistor 2. The fifth field effect transistor 5 and the series resonance circuit 51 are connected in series and attached between the common input-output terminal 21 and the ground so as to divert the higher harmonic of the signal without giving passing loss to the signal.
    Type: Grant
    Filed: March 29, 2001
    Date of Patent: June 18, 2002
    Assignee: New Japan Radio Co., Ltd.
    Inventor: Masaru Takahashi
  • Publication number: 20020070790
    Abstract: A transfer switch having a test signal input and first and second ports. The transfer switch includes a first routing switch and first and second port termination switches. The first routing switch has a routing switch input for receiving the test signal input and first and second outputs. Each output is connected to the routing switch input by a first switching element and each output is connected to ground by a second switching element. The first and second port termination switches are connected to the first and second outputs, respectively, of the first routing switch. Each termination switch includes a common-base transistor, and preferably, a Darlington amplifier with feedback. The common-base transistor is connected to the output of the routing switch and the Darlington amplifier has an output connected to a corresponding one of the first and second ports.
    Type: Application
    Filed: December 12, 2000
    Publication date: June 13, 2002
    Inventor: Stephen J. Westerman
  • Patent number: 6404264
    Abstract: A fuse latch for a memory circuit according to the present invention comprises a plurality of address lines, a control signal line provided from a fuse, a multiplexer for multiplexing the plurality of address lines in response to the control signal wherein the multiplexer has only one type transistors, and a decoder for receiving a multiplexed signal from the multiplexer. Since the multiplexer has a smaller size than that of a conventional CMOS multiplexer, a fuse latch circuit of the present invention has a smaller size than that of a conventional fuse latch. The multiplexer preferably has only NMOS transistors. To overcome a voltage drop due to an NMOS threshold voltage, the present invention uses low-threshold NMOSs and/or boosts the transistors in the multiplexer. Alternatively, the voltage drop is successfully converted into a CMOS level by using a dynamic logic circuit.
    Type: Grant
    Filed: December 6, 1999
    Date of Patent: June 11, 2002
    Assignees: Infineon Technologies North America Corp., International Business Machines Corporation
    Inventors: Gabriel Daniel, Toshiaki Kirihata
  • Publication number: 20020067200
    Abstract: A switching element including first, second and third ports each comprising a plurality of lines is disclosed. A first memory cell includes a storage element, a first pass gate for selectively coupling a first line of the first port to the storage element, a second pass gate for selectively coupling a first line of the second port to the storage element, and a third pass gate for selectively coupling a first line of the third port to the storage element. A second memory cell includes a storage element, a first gate for selectively coupling a second line of the first port to the storage element, a second pass gate for selectively coupling a second line of the second port to the storage element, and a third pass gate for selectively coupling a second line of the third port to the storage element.
    Type: Application
    Filed: December 4, 2000
    Publication date: June 6, 2002
    Inventor: Gautam Nag Kavipurapu
  • Patent number: 6400735
    Abstract: A glitchless delay line using a Gray code multiplexer is provided. The glitchless delay line combines a multi-tap delay circuit with the Gray code multiplexer. Specifically, the multi-tap delay circuit provides a plurality-of sequentially ordered delayed output signals on a plurality of sequentially ordered output terminals. The Gray code multiplexer has a plurality of input terminals coupled to the sequentially ordered delayed output terminals. The Gray code multiplexer is controlled by driving a Gray code value onto the control terminals of the Gray code multiplexer to select a specific delayed output terminal of the multi-tap delay circuit. The delay provided by the delay line is increased by incrementing the Gray code value on the control terminals of the Gray code multiplexer and decreased by decrementing the Gray code value on the control terminals. Race conditions on the control lines are eliminated when incrementing or decrementing the Gray code value by one.
    Type: Grant
    Filed: June 22, 1998
    Date of Patent: June 4, 2002
    Assignee: Xilinx, Inc.
    Inventor: Andrew K. Percey
  • Patent number: 6400197
    Abstract: A signal delay device having an internal delay lock loop for calibrating the delay interval. The signal delay device receives an input signal and then outputs the signal after a pre-defined delay period. The input signal varies according to a reference clock signal, and the required delay period is a quarter cycle of the clock signal. The delay device includes a multiplexer, an inverter, a phase detector, a counter and a delay element. During calibration, the phase detector, the counter and the delay element form a delay lock loop that can set up the delay time automatically.
    Type: Grant
    Filed: January 22, 2001
    Date of Patent: June 4, 2002
    Assignee: VIA Technologies, Inc.
    Inventors: Jiin Lai, Hsin-Chieh Lin, Kuo-Ping Liu
  • Patent number: 6396324
    Abstract: A clock system is provided capable of using an external system clock for driving at least one charge circuit of a semiconductor memory unit for restoring and refreshing a data array of the memory unit. The clock system, in one embodiment, includes a plurality of control circuits each having a clock select circuit which has as an input the external system clock, an internal clock generator circuit for generating an internal system clock, and a multiplexer. The multiplexer has as inputs an output of the clock select circuit, i.e., the external system clock, and an output of the internal clock generator circuit, i.e., the internal system clock. The multiplexer outputs either the external system clock or the internal system clock to the at least one charge circuit according to at least one control signal transmitted by a central processing unit to the clock select circuit.
    Type: Grant
    Filed: May 8, 2000
    Date of Patent: May 28, 2002
    Assignee: International Business Machines Corporation
    Inventors: Louis L. Hsu, Rajiv V. Joshi, Richard M. Parent, Matthew R. Wordeman
  • Publication number: 20020053937
    Abstract: A circuit for modifying a clock pulse train is described. The circuit has an input for receiving the clock pulse train, a first logic circuit having an output which is responsive to a clock pulse edge of a first polarity and a second logic circuit having an output which is responsive to a clock pulse edge of a second polarity. A two input multiplexer is provided to receive respectively the outputs of the first and second logic circuits and is arranged to provide an output representing a modification of the input clock pulse train.
    Type: Application
    Filed: June 21, 2001
    Publication date: May 9, 2002
    Inventor: Alan Lloyd
  • Patent number: 6385214
    Abstract: A signal multiplexing circuit capable of reducing jitter provided with a first circuit for outputting input differential data by receiving a select drive signal comprising first and second NMOS transistors whose sources are commonly connected, a second circuit for outputting the input differential data with an inverted phase with respect to the output of the first circuit so as to add it to the output of the first circuit and never being selected by a select drive signal comprising third and fourth transistors whose sources are commonly connected, and a signal extracting circuit configured by connecting a connecting point of the sources of the first and second transistors to an output line of a select drive signal of a selector. As a result, jitter of the output signal can be reduced.
    Type: Grant
    Filed: January 15, 1999
    Date of Patent: May 7, 2002
    Assignee: Sony Corporation
    Inventors: Hidekazu Kikuchi, Norihito Suzuki
  • Patent number: 6377108
    Abstract: A differential amplifier is provided, incorporating negative hysteresis by automatic reference voltage adjustment. A delayed output signal is routed to a switch or multiplexer which functions to select one of two reference voltage levels, creating negative hysteresis. The delayed output signal is delayed by a series of inverters, which prevent certain embodiments of the invention from oscillating under some conditions. The two reference voltage levels are selected to be near the respective data signal input high and low signal voltage levels, but far enough from these levels so as not to be adversely affected by noise or other interference.
    Type: Grant
    Filed: August 28, 2000
    Date of Patent: April 23, 2002
    Assignee: Intel Corporation
    Inventors: Joseph T. Kennedy, Stephen R. Mooney, Aaron K. Martin, Rajendran Nair
  • Patent number: 6369637
    Abstract: High-bandwidth, analog multiplexer circuits with low signal feed-through and good common mode properties are described. These are BiCMOS circuits with N-MOS control transistors which emphasize low parasitic capacitance through circuit layout techniques and the use of smaller geometry devices where possible. These circuits can be used in both single-ended and differential configurations and address applications having multiplexing ratio requirements ranging from 2-to-1 up to many-to-1.
    Type: Grant
    Filed: September 11, 2000
    Date of Patent: April 9, 2002
    Assignee: Texas Instruments Incorporated
    Inventor: Sami Kiriaki
  • Patent number: 6369636
    Abstract: A circuit including a plurality of first calibration circuits, a second circuit and a third circuit. The plurality of calibration circuits may each be configured to present a calibration signal. The second circuit may be configured to select one of the calibration signals in response to a plurality of configuration signals. The third circuit may be configured to generate a control signal in response to (i) a reference signal and (ii) the selected calibration signal.
    Type: Grant
    Filed: December 21, 1999
    Date of Patent: April 9, 2002
    Assignee: Cypress Semiconductor Corp.
    Inventor: Gabriel Li
  • Patent number: 6362680
    Abstract: An output circuit which can minimize the delay in combining two clocks comprises a multiplexer with a flip flop connected to one input and a clocked latch connected to the other. The clocked latch is transparent during one clocking state so that changes to its input appear directly at its output.
    Type: Grant
    Filed: October 17, 2000
    Date of Patent: March 26, 2002
    Assignee: STMicroelectronics Limited
    Inventor: William Bryan Barnes
  • Publication number: 20020024376
    Abstract: The present invention relates to a circuit arrangement having a load transistor (T1) and a current sensing transistor (T2) coupled to the load transistor (T1), wherein a switch arrangement (S) having at least one first switch (S1; S1a, S1b) is connected downstream of the current sensing transistor (T2) in order to connect the current sensing transistor (T2) to a first or second evaluation circuit (BL1, BL2) depending on a control signal.
    Type: Application
    Filed: August 30, 2001
    Publication date: February 28, 2002
    Inventor: Rainald Sander
  • Patent number: 6351150
    Abstract: A high performance interconnect that utilizes dynamic driver technology is capable of reduced power operation during periods of low data switching activity. Circuitry is provided that limits the performance of an evaluation operation in the dynamic driver circuitry to clock cycles during which a present input bit of the interconnect differs from a previous input bit. Thus, the evaluation operation and subsequent precharge of the driver output is performed sparingly during periods of low data switching activity. An output circuit is also provided for decoding the data stream flowing through the interconnect at the receiver end thereof. Using the principles of the present invention, it is possible to achieve the performance advantages of dynamic drivers with the switching activity of interconnects that use static CMOS technology.
    Type: Grant
    Filed: September 11, 2000
    Date of Patent: February 26, 2002
    Assignee: Intel Corporation
    Inventors: Ram K. Krishnamurthy, Mark A. Anders, Atila Alvandpour
  • Publication number: 20020011892
    Abstract: A current output circuit with two output nodes connectable to a load and providing a plurality of discretely selectable current output magnitudes is provided. The circuit consists of a current driver attached across the output nodes supplying a particular current and one or more bypass resistors connected in parallel with the output nodes that can be switched between a non-conducting state and a resistive conducting state. When a load is connected across said output nodes, the particular magnitude of current sourced through the load can be selected by switching the state of the bypass resistors. The magnitude of the bypass resistors is preselected to provide several discretely selectable states of output current of substantial equal steps. The current driver can be combined with a current switch to increase the number of output states. Several current drivers with current switches may be provided and the bypass resistors integrated into the current switch itself.
    Type: Application
    Filed: August 23, 2001
    Publication date: January 31, 2002
    Applicant: Agere Systems Guardian Corp.
    Inventor: Thaddeus John Gabara
  • Patent number: 6342805
    Abstract: A system and method for selecting an output of an associated circuit includes a pair of inputs for receiving different relative voltage levels. A first switch is operatively coupled to a first of the inputs and a second switch operatively coupled to a second of the inputs. Each of the first and second switches operates mutually exclusively according to the voltage potential between the pair of inputs. A third switch is operatively coupled between a first output of the associated circuit and the first switch. When the third switch is activated in response to activation of the first switch, it couples the first output to an output node. The system further includes a fourth switch operatively coupled between a second output of the associated circuit and the second switch. When the fourth switch is activated in response to activation of the second switch, it couples the second output to the output node.
    Type: Grant
    Filed: June 15, 2000
    Date of Patent: January 29, 2002
    Assignee: Rockwell Automation Technologies, Inc.
    Inventor: Zhenhai Chen
  • Patent number: 6339357
    Abstract: A test on a desired internal voltage is easily and accurately conducted without increasing current dissipation or the number of pads. A driving circuit receiving a reference voltage from a reference voltage generating circuit has a high input impedance and low output impedance, and generates a voltage substantially at the same voltage level as the reference voltage received, and transmits the generated voltage to a pad with a current driving capability larger than the driving current capability of the reference voltage generating circuit.
    Type: Grant
    Filed: February 13, 1998
    Date of Patent: January 15, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kyoji Yamasaki, Takashi Itou
  • Patent number: 6323690
    Abstract: This application proposes a new logic circuit including the 1st selector (S1) in which the control input S is controlled by the first input signal (IN1), the input I1 or I0 is controlled by the second input signal (IN2), and the output O is connected to the first node (N1), and the 3rd selector (S3) in which the control input S is controlled by the first node (N1), the input I1 is controlled by the third input signal (IN3), the input I0 is controlled by the first input signal (IN1), and the output is connected to the first output signal (OUT1).
    Type: Grant
    Filed: July 5, 2000
    Date of Patent: November 27, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Shunzo Yamashita, Kazuo Yano, Yasuhiko Sasaki
  • Patent number: 6323715
    Abstract: A method and apparatus adapted for glitchless switching between unrelated clock signals is achieved using simple AND/OR logic gates to form the circuit that synchronizes the clock inputs. In an example embodiment of the present invention, two clock signals are generated along with a select input signal capable of deselecting one of the clock signals and delaying selection of the second clock input signal. The first and second clock signals and the select input signal are multiplexed to generate a multiplexed output clock signal corresponding to one of the input clock signals. A selection delay is generated between the deselection of the first clock signal and the selection the second clock signal that is longer than the low pulse width of the minimum low pulse width of the first clock signal and the low pulse width of the second clock signal, such that switching between clock signals will not create a glitch at the multiplexed output.
    Type: Grant
    Filed: December 30, 1999
    Date of Patent: November 27, 2001
    Assignee: Koninklijke Philips Electronics N.V. (KPEUV)
    Inventor: Christophe Vatinel
  • Patent number: 6320447
    Abstract: The circuit configuration has at least five single-electron transistors, three of which are connected via a second main node and a third main node between a first main node and an output. The fourth single-electron transistor is connected between the second main node and a first supply voltage, with its gate electrode being connected to the first main node. The fifth single-electron transistor is connected between the third main node and the first supply voltage, with its gate electrode being connected to the second main node. The circuit configuration is suitable for use as a full adder and as a multiplier.
    Type: Grant
    Filed: November 6, 2000
    Date of Patent: November 20, 2001
    Assignee: Infineon Technologies AG
    Inventors: Wolfgang Rösner, Ties Ramcke, Lothar Risch
  • Patent number: 6316991
    Abstract: A voltage out-of-calibration detector 200 includes a voltage divider operating between first and second voltage rails and having a plurality of taps 203 for generating first and second comparison voltages. A first set of switches 205 selectively couples at least one of the plurality of taps 203 to the input of a first voltage comparator 401a, first voltage comparator 401a comparing the first comparison voltage with an input voltage and outputing a signal when the input voltage exceeds the first comparison voltage. A second set of switches 206 selectively couples at least one of the plurality of taps 203 to an input of a second voltage comparator 401b, second voltage comparator 401b comparing the second comparison voltage with the input voltage and outputing a signal when the input voltage is below the second comparison voltage. Control logic 300 selectively activates the first and second sets of switches 205/206 in response to received control signals.
    Type: Grant
    Filed: March 29, 2000
    Date of Patent: November 13, 2001
    Assignee: Cirrus Logic, Inc.
    Inventors: Gabriel Patrick Muyshondt, Zheng Luo
  • Patent number: 6310509
    Abstract: A multiplexer includes a first input device that receives a first input signal and a first select signal. When the first select signal has a first state, the first input device generates a first voltage at a first node in response to the first input signal. When the first select signal has a second state, the first input device generates a first reference voltage at the first node. A second input device receives a second input signal and a second select signal related to the first select signal. When the second select signal has a first state, the second input device generates a second voltage at a second node in response to the second input signal. When the second select signal has a second state, the second input device generates a second reference voltage at the second node. A first output buffer has an input terminal coupled to the first node and an output terminal coupled to an output node.
    Type: Grant
    Filed: December 8, 1998
    Date of Patent: October 30, 2001
    Assignee: TriQuint Semiconductor, Inc.
    Inventors: William H. Davenport, Andy Turudic
  • Publication number: 20010030569
    Abstract: A multiplexer circuit is disclosed for switching a selected one of a plurality of current inputs carried by respective input lines (2;101) to a common output. The circuit comprises, for each input line, a diode clamp (5;104) and isolation means (10;109) provided between each input line and the common terminal The diode clamp (5;104) is operable in a first mode in which voltages are applied to the clamp terminals such that the diodes (8,9;107,108) of the diode clamp are forward biased and hold the input line (2;101) at a first voltage which prevents the passage of current from the input line to the common output, and a second mode in which the voltages are applied to the clamp terminals such that the diodes of the diode clamp are reverse biased and the passage of the current from the input line to the common output is allowed. Only two connections, for the diode clamp, are needed to control the switching of the current input, and the switch introduces no current offset to the output.
    Type: Application
    Filed: December 19, 2000
    Publication date: October 18, 2001
    Applicant: U.S. PHILIPS CORPORATION
    Inventor: Neil C. Bird
  • Patent number: 6300830
    Abstract: A circuit for providing a multiplexed input to an amplifier load matching network. The circuit includes a control device receiving amplitude information and phase information from a primary waveform, a plurality of switching devices in communication with the control device and the amplifier, wherein each of the switching devices has a different “ON” resistance. The control device uses the amplitude information to select an active switching device and to control the device using phase information to create a secondary waveform for input to the load matching network. In this way, an amplitude modulated waveform is amplified at high efficiency, enabling application of either all or part of the phase and/or amplitude modulation at the input of the amplifier.
    Type: Grant
    Filed: December 29, 2000
    Date of Patent: October 9, 2001
    Assignee: Ericsson INC
    Inventor: David R. Pehlke
  • Patent number: 6300809
    Abstract: An apparatus comprising a clock for providing a clock signal, means for providing a delayed version of the clock signal, two transparent latches having clock inputs controlled by opposite polarities of the delayed clock signal, a multiplexer having (i) inputs fed by outputs of the latches, and (ii) a select input fed by the clock signal, and means for providing a select signal for selecting the latch whose clock is inactive. Preferably, each of the latches has a scan input gate and a scan output gate, and the scan output of the first latch is applied to the scan input of the second latch to form a scannable latch pair. Also, preferably, the apparatus further comprises a data port for applying data to the first and second latches, and an exclusive OR gate at the data port, whereby the apparatus produces a gated clock signal. Also disclosed is a method of operating this apparatus.
    Type: Grant
    Filed: July 14, 2000
    Date of Patent: October 9, 2001
    Assignee: International Business Machines Corporation
    Inventors: Roger Paul Gregor, David James Hathaway, David E. Lackey, Steven Frederick Oakland
  • Patent number: 6300816
    Abstract: A circuit for discriminating between complementary first and second input signals. By using a logic gate in parallel with a signal amplifying circuit, the signal amplifying circuit can be disabled when it is no longer required. Once the logic gate is capable of detecting distinct complementary states in the two input signals, the signal amplifying circuit is disabled and the circuit uses one of the input signals as its output signal. The circuit is improved by using a pair of Schmitt inverters so the logic circuit will not vacillate unpredictably when the input signals are in an indeterminate state.
    Type: Grant
    Filed: October 24, 2000
    Date of Patent: October 9, 2001
    Assignee: Rosun Technologies, Inc.
    Inventor: Huy Nguyen
  • Patent number: 6297679
    Abstract: The present invention discloses an input buffer which can improve the properties of a setup time and a hold time of an input signal. When the setup time is important, a path of a short delay time is employed, and when the hold time is important, a path of a long delay time is used. Therefore, the internal setup time/hold time may be suitably selected in the system application conditions. For this, the input buffer includes: a buffer for receiving a signal through an input pin; a plurality of delay units for delaying the signal inputted from the buffer by a different delay time; and a selecting unit for selectively outputting one of the output signals from the plurality of delay units according to an externally-inputted reference signal and the logic variation of the input signal from the buffer.
    Type: Grant
    Filed: June 22, 2000
    Date of Patent: October 2, 2001
    Assignee: Hyundai Electronics Industries Co., Ltd.
    Inventor: Yong Ki Kim
  • Patent number: 6292044
    Abstract: A glitch-free clock switch circuit for an integrated circuit having a plurality of asynchronous clocks, wherein only one clock is selected at a time, and wherein the clock switching circuitry for switching from a currently selected clock to an inactive clock to next be selected is activated only for the time it takes to complete the switching. The clock switch circuit includes at least three sets of clock drivers, wherein each set is comprised of two drivers and separate clock drivers are each associated with the output clock, the currently selected clock and the clock to next be selected, respectively. An edge detector turns on these clock drivers in response to a clock select signal, and a set of synchronizers receive and synchronize the clock select signal first with the output clock and then with the currently selected clock and the clock to next be selected, respectively.
    Type: Grant
    Filed: March 26, 1999
    Date of Patent: September 18, 2001
    Assignee: Lucent Technologies Inc.
    Inventors: Jiancheng Mo, Feng Chen, Marc Stephen Diamondstein
  • Patent number: 6285237
    Abstract: An inventive integrated circuit die includes a bond pad connected to first and second input buffers in the die through laser fuses. In one operating configuration of the die, the die uses the first input buffer but does not use the second input buffer, so the laser fuse between the bond pad and the second input buffer is blown. In another operating configuration of the die, the die uses the second input buffer but does not use the first input buffer, so the laser fuse between the bond pad and the first input buffer is blown. As a result, the capacitive load on the bond pad is similar to the capacitive load on similar bond pads in the die connected to only one input buffer in the die. Thus, signals propagate into all the bond pads at about the same improved speed.
    Type: Grant
    Filed: August 19, 1998
    Date of Patent: September 4, 2001
    Assignee: Micron Technology, Inc.
    Inventor: Joseph C. Sher
  • Patent number: 6265930
    Abstract: A clock selector circuit for selecting a single output clock signal from a multiplicity of input clock signals, each constituted by transitions between binary states, comprises a multiplicity of D-bistables each having a clock input coupled to receive the respective one of the input clock signals, a D-input coupled to receive a hold signal common to the bistables, and an output for providing a respective hold signal. A first multiplexer has inputs coupled to receive the respective input clock signals and is operative to select in response to the selection signal one of said input signals. A second multiplexer has inputs coupled to receive the respective hold signals and is operative to select in response to the selection signal the hold signal corresponding to the clock signal selected by the first multiplexer.
    Type: Grant
    Filed: May 3, 2000
    Date of Patent: July 24, 2001
    Assignee: 3Com Corporation
    Inventors: Christopher Walker, Robin Parry, Justin A Drummond-Murray
  • Patent number: 6252551
    Abstract: To provide an antenna unit that can always provide good broadcast transmission reception and a signal switching circuit to be used therein. A first antenna element for receiving satellite broadcast transmissions, a second antenna element for receiving VHF terrestrial broadcast transmissions, and a switching means for selectively switching output of either a reception signal of the satellite broadcast transmissions received by the first antenna element or a reception signal of the VHF terrestrial broadcast transmissions received by the second antenna element and supplying that output to the receiver unit via the signal supply cable in response to a direct-current bias level supplied from a receiver unit via a signal supply cable are provided inside a single identical casing.
    Type: Grant
    Filed: June 21, 1999
    Date of Patent: June 26, 2001
    Assignee: Mitsumi Electric Co., Ltd.
    Inventors: Junichi Noro, Nobuaki Monma, Hirokazu Awa, Nobuo Tamura, Takeshi Saito
  • Patent number: 6239626
    Abstract: A pair of synchronized clock sources provides phase and frequency synchronous first and second clocks accompanied by first and second control signals to a clock selection circuit having a data selector comprising a first synchronizer and a second synchronizer which re-times the first and second control signals, and these re-timed outputs that are coupled to an asynchronous state machine. The asynchronous state machine changes state by logically operating on the re-timed control signals in conjunction with a state bit. This state bit is used to control the multiplexer, which achieves glitch-free switching between the first clock source and the second clock source.
    Type: Grant
    Filed: January 7, 2000
    Date of Patent: May 29, 2001
    Assignee: Cisco Technology, Inc.
    Inventor: Jay A. Chesavage
  • Patent number: 6239646
    Abstract: A circuit comprising a plurality of input devices, a plurality of select devices and a selector device. The plurality of inputs may each be configured to receive an input. The plurality of select devices may each be configured to present an output in response (i) one of said plurality of inputs and (ii) one of a plurality of select signals. The selector device may be configured to present the plurality of select signals, where only one of the select signals is active at a time.
    Type: Grant
    Filed: October 29, 1998
    Date of Patent: May 29, 2001
    Assignee: Cypress Semiconductor Corp.
    Inventors: Mohammad J. Navabi, Kamal Dalmia
  • Patent number: 6232824
    Abstract: First and second buffer circuits generate first and second reference potentials. A switching circuit selects a first reference potential as a reference potential while a sense operation is not performed and selects a lower second reference potential while the sense operation is performed. A buffer circuit is controlled such that a through current increases only for a predetermined time period at a initiation and a termination of the sense operation.
    Type: Grant
    Filed: November 15, 1999
    Date of Patent: May 15, 2001
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Takashi Kono
  • Patent number: 6229344
    Abstract: Phase selection circuit for selecting a phase from signal source generating a multi-phase clock signal is implemented utilizing a single stage of multiplexing gates for receiving taps from signal source, thus minimizing mismatch between phases. Multiplexing gates, connected together at their outputs, select between a tap and an inverse tap and are always left on. The outputs from multiplexing gates are analog summed together to create a single phase output signal which may be shifted in phase by one tap simply by inverting one of the input taps to a multiplexing gate, thus reducing glitching at output signal. Phase interpolation is provided for by further phase shifting the output in steps smaller than one tap utilizing multiplexor circuit which interpolates in multiple steps between a tap and inverse tap. Phase selection circuit provides for provides maximum bandwidth capability, while minimizing mismatch and glitching.
    Type: Grant
    Filed: March 9, 1999
    Date of Patent: May 8, 2001
    Assignee: Vitesse Semiconductor Corp.
    Inventor: Greg Warwar