Complementary Clock Inputs Patents (Class 327/201)
  • Patent number: 6028455
    Abstract: In transmitting a first pair of differential clock signals UCLK, UXCLK having an extremely small amplitude voltage based on a power-source potential and a second pair of differential clock signals LCLK, LXCLK having an extremely small amplitude voltage based on the power-source potential, an inverting circuit as a signal receiving circuit is composed of a CMOS inverting circuit. A PMOS transistor composing the CMOS inverting circuit has a gate electrode and a source electrode receiving the first pair of differential clock signals. An NMOS transistor composing the CMOS inverting circuit has a gate electrode and a source electrode receiving the second pair of differential clock signals. When the potentials of the differential clock signals change, potentials at the respective gate and source electrodes of the two transistors shift in opposite directions, which surely cuts off the transistors.
    Type: Grant
    Filed: December 19, 1997
    Date of Patent: February 22, 2000
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Hiroyuki Yamauchi
  • Patent number: 6018260
    Abstract: A novel latch circuit configuration that substantially reduces inverter-based setup and hold times. The latch circuit includes first and second input switches connected to an effective sense amplifier configuration. It is possible for the input switches to receive complementary signals of a balanced input signal. The latch circuit operates in initialization and output modes based on the signal level of an alternating clock signal. The output mode produces an output signal having a first or second signal magnitude based on the magnitude of the input signal at the end of the initialization mode. Also, disclosed is a high-speed serial-to-parallel converter based on this latch circuit.
    Type: Grant
    Filed: August 6, 1997
    Date of Patent: January 25, 2000
    Assignee: Lucent Technologies Inc.
    Inventor: Thaddeus John Gabara
  • Patent number: 5977808
    Abstract: A latch circuit receives complementary signals and consists of an nMOS transistor whose source is connected to an input terminal of the latch circuit and a series-connected circuit consisting of first and second pMOS transistors arranged between and connected to a drain terminal of the nMOS transistor and a high-potential power supply. The complementary signals are a first signal and a second signal that is an inversion of the first signal. Each of the signals has a pulse characteristic that rising time is longer than falling time. The latch circuit latches a quick fall by passing the first signal through the nMOS transistor. On the other hand, the latch circuit latches a slow rise by turning on the second pMOS transistor in response to a fall in the second signal.
    Type: Grant
    Filed: August 12, 1997
    Date of Patent: November 2, 1999
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naoka Yano, Hiroaki Murakami, Yukinori Muroya
  • Patent number: 5942916
    Abstract: A logic circuit has a signal line for transmitting a digital signal as a voltage level and a loop circuit serving as a memory unit for storing the digital signal. Input and output terminals of the loop circuit are connected to the signal line. The loop circuit is a partial circuit having an even number (at least two) of signal inverters each having capacitive input load. At least one of the input and output terminals of the loop circuit is connected to an electric resistor. The loop circuit has a time constant T that is determined by the product RC of the resistance R of the resistor and the intentional and parasitic capacitance C of the signal inverters. The time constant T has a given relationship with the operation frequency of the logic circuit. The resistance R and capacitance C form a low-pass filter. The logic circuit provides different equivalent circuits in high and low frequency regions above and below the cutoff frequency of the low-pass filter.
    Type: Grant
    Filed: August 14, 1996
    Date of Patent: August 24, 1999
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Gensoh Matsbara, Chikahiro Hori
  • Patent number: 5903180
    Abstract: A voltage tolerant bus hold latch comprises a first buffer transistor, a sense transistor, a low voltage latch, a node voltage controller and a pull-up circuit. The low voltage latch is coupled to the input by the first transistor. The node voltage controller is coupled to the input by the sense transistor. The node voltage controller has a pair of additional inputs coupled to the output of the low voltage latch. The output of the node voltage controller is coupled to control the operation of the pull-up circuit. The pull-up circuit is coupled to the supply voltage for the lower voltage circuitry, and has another control input coupled to the output of the low voltage latch. The output of the pull-up circuit is coupled to the input of the voltage tolerant latch. The pull-up circuit is selectively activated to pull the input of the latch to a high voltage level.
    Type: Grant
    Filed: July 24, 1997
    Date of Patent: May 11, 1999
    Assignee: S3 Incorporated
    Inventors: Yuwen Hsia, Sarathy Sribhashyam
  • Patent number: 5900758
    Abstract: A dynamic latch circuit or a dynamic flip-flop circuit of the present invention includes a transfer gate to be controlled by a clock and provided with a complementary configuration using a P-channel and an N-channel MOS (Metal Oxide Semiconductor) transistor. The transfer gate allows the individual node included in the circuit to fully swing between a high potential power source and a low potential power source. This causes a minimum of decrease to occur in an ON current for driving the respective node and thereby realizes high-speed operation. Further, the balance of the rising time and falling time of an output signal is improved, reducing the deviation of the duty of the output signal from 50%. The circuit is therefore operable with sufficient operation margins at positive- and negative-going edges. Consequently, the entire macrocircuit using the circuit of the present invention can have its operation frequency and therefore power consumption lowered.
    Type: Grant
    Filed: June 17, 1997
    Date of Patent: May 4, 1999
    Assignee: NEC Corporation
    Inventor: Hiroshi Kanno
  • Patent number: 5900759
    Abstract: A staticized flop circuit converts a dynamic signal appearing across the output of a logic circuit into a static signal, and includes a dynamic-to-static convertor which minimizes glitching in the static output. The dynamic-to-static convertor includes a pull-down device, operatively coupled between an output node and a ground, which is closed while an input node is at a precharge potential and which is open while the input node is at a ground potential, and a pull-up device, operatively coupled between a source voltage and the output node, which is closed while the input node is at the ground potential and which is open while the input node is at the precharge potential.
    Type: Grant
    Filed: June 26, 1997
    Date of Patent: May 4, 1999
    Assignee: Sun Microsystems, Inc.
    Inventor: Kenway W. Tam
  • Patent number: 5867049
    Abstract: Circuits and methods for a zero setup time storage element are disclosed. A storage element having a data input terminal, a clock input terminal and a data output terminal is able to capture a logic value of a data signal on the data input terminal with a substantially zero setup time at an active edge of a clock signal. Furthermore, some embodiments of the storage element are able to drive the captured logic value until the next active edge. One embodiment of the storage element includes a control circuit coupled to an output driver circuit. Depending on the state of the data input signal during an active edge, the control circuit can drives a first control signal to the output driver circuit or a second control signal to the output driver circuit. The output driver drives a data output signal on the data output terminal of the storage element based on the values of the control signals.
    Type: Grant
    Filed: November 21, 1996
    Date of Patent: February 2, 1999
    Assignee: Sun Microsystems, Inc.
    Inventor: Bassam J. Mohd
  • Patent number: 5815019
    Abstract: Disclosed herein is a flip/flop circuit of a master-slave type including master side and slave side latch/hold circuits 1 and 2 each being of an ECL vertical 1-step construction, first and second bias circuits 3 and 4 for biasing current sources Tr's 21 to 24 of these latch/hold circuits 1 and 2 and a control circuit 5 for pull-down controlling these first and second bias circuits 3 and 4 by clock signals. The current sources Tr's 21 to 24 are thus selectively rendered conductive and non-conductive to perform a flip-flop operation on a low power source voltage such as 1V or less.
    Type: Grant
    Filed: September 23, 1996
    Date of Patent: September 29, 1998
    Assignee: NEC Corporation
    Inventors: Gohiko Uemura, Jun Yoshida
  • Patent number: 5663669
    Abstract: A method and circuitry are provided for latching information. The information is selectively transferred from a selected one of: a first node (DIN) to a second node (416); and a third node (SIN) to a fourth node (419a-b). The transferred information is selectively latched by coupling the second node (416) to the fourth node (419a-b) in response to a signal (308, 410).
    Type: Grant
    Filed: March 26, 1996
    Date of Patent: September 2, 1997
    Assignee: International Business Machines Corporation
    Inventor: Neil Ray Vanderschaaf
  • Patent number: 5646555
    Abstract: To obtain a semiconductor integrated circuit reduced in hardware size, by avoiding duplication of a common constitution. A logic block (100) comprises logic means (A), logic means (B), and logic means (C), and the output of a pipeline register (11) is connected to the logic means (A) through a signal line (a), and the logic means (A) and logic means (B) are connected through a signal line (b). The logic means (A) is also connected to the logic means (C) through a signal line (c), and the logic means (C) is connected to the input of a pipeline register (21) through a signal line (d). When performing the same logic action in the first half period and second half period of a clock signal, it is not necessary to install two identical logic means, so that the size of the hardware may be reduced as compared with the constitution of installing two identical logic means.
    Type: Grant
    Filed: October 25, 1995
    Date of Patent: July 8, 1997
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Hiroyuki Morinaka
  • Patent number: 5596296
    Abstract: A clock driver circuit comprises a first driver including first and second inverters cascaded between an input terminal and a first output terminal for outputting a non-inverted signal delayed from the clock signal applied to the input terminal by a delay amount corresponding to two stages of inverters. The clock driver circuit also comprises and a second driver including third, fourth and fifth inverters cascaded between the input terminal and a second output terminal and a sixth inverter connected between the input terminal and the second output terminal. With this arrangement, a first signal delayed from the clock signal applied to the input terminal by a first delay amount corresponding to the third, fourth and fifth inverters, is synthesized by a wired-OR at the second output terminal with a second signal delayed from the clock signal applied to the input terminal by a second delay amount corresponding to the sixth inverter.
    Type: Grant
    Filed: March 30, 1995
    Date of Patent: January 21, 1997
    Assignee: NEC Corporation
    Inventor: Hiroshi Asazawa
  • Patent number: 5546035
    Abstract: A latch circuit with an NAND function comprises a three-input NAND gate circuit, a first transfer gate connected between a first input terminal and a first input of the NAND gate circuit, a second transfer gate connected between a second input terminal and a second input of the NAND gate circuit, and a third transfer gate connected between a third input terminal and a third input of the NAND gate circuit. An input of a feedback inverter is connected To an output of the NAND gate circuit, and an output of the feedback inverter is connected to the first input of the NAND gate circuit through a fourth transfer gate. The second and third inputs of the NAND gate circuit are pulled up to a logical high level through P-channel MOS transistors.
    Type: Grant
    Filed: February 17, 1995
    Date of Patent: August 13, 1996
    Assignee: NEC Corporation
    Inventor: Fuyuki Okamoto
  • Patent number: 5517145
    Abstract: A toggle flip-flop circuit is described incorporating eight bi-directional switches which may be dual rail wherein each bi-directional switch for each rail includes an n and p channel transistor coupled in parallel. Clock input signals may have rise and fall times longer than the RC time constant of a bi-directional switch and node capacitance being charged which dissipates, very low power across the switch. The invention provides a practical toggle flip-flop circuit using adiabatic switching for very low power dissipation.
    Type: Grant
    Filed: October 31, 1994
    Date of Patent: May 14, 1996
    Assignee: International Business Machines Corporation
    Inventor: David J. Frank
  • Patent number: 5463340
    Abstract: A general object of the present invention is to provide a latch of which demand is small. In a half-latch 101, control signals T2 and T2C which vary at late timings are applied to a main unit for data input (update) operation while control signals T1 and T1C which vary at early timings are applied to a feedback unit for data retaining operation. The data input (update) operation is never started until the data retaining operation is completed. The data retaining operation is practiced by retaining two signals having a negative logic relation with each other in a loop made up with two inverters. A signal related to retension of data and a signal newly input never reside in the same signal line. Thus, collision of those signals is avoided, and consequently, through-current due to the collision of the signals can be reduced.
    Type: Grant
    Filed: June 15, 1993
    Date of Patent: October 31, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Akihiko Takabatake, Shinichi Uramoto, Shinichi Nakagawa
  • Patent number: 5455531
    Abstract: A flip-flop circuit which has a low power requirement and is capable of high-speed operation has first and second latch circuits having respective clock input terminals connected respectively to inverted- and normal-phase clock input terminals, a pair of differential data input terminals connected respectively to the differential signal input terminals of the first latch circuit, a pair of differential output terminals connected respectively to the differential signal output terminals of the second latch circuit, and a power supply and a current source, each connected to the first and second latch circuits. Each of the first and second latch circuits has first and second current mirror circuits energizable by the power supply, and first through fifth MOS transistors, each of the first and second latch circuits being of a dynamic type.
    Type: Grant
    Filed: June 16, 1994
    Date of Patent: October 3, 1995
    Assignee: NEC Corporation
    Inventor: Shigeki Morisaki
  • Patent number: 5391935
    Abstract: An assertive latching flip-flop circuit is provided which prevents the occurrence of metastable outputs. The circuit comprises a single flip-flop which is comprised of standard switching transistors which are switched by a clocking mechanism having no additionally introduced delay. The circuit includes an imbalancing element which is coupled to a latching portion of the circuit. The latching portion of the circuit comprises a pair of cross-coupled transistors, in current mode embodiments of the invention, or a pair of cross-coupled inverters, in voltage mode embodiments of the invention. The imbalancing element introduces an electrical disturbance on the input line to one of the latching transistors or inverters. The imbalancing element is a capacitor in voltage mode embodiments of the invention and an additional transistor in current mode embodiments.
    Type: Grant
    Filed: July 22, 1993
    Date of Patent: February 21, 1995
    Assignee: International Business Machines Corporation
    Inventors: John E. Gersbach, Paul W. Chung