Complementary Metal-oxide Semiconductor (cmos) Patents (Class 327/437)
  • Patent number: 6236259
    Abstract: A bus switch for transferring logic signals between nodes without the problems associated with undershoot conduction. The bus switch is an FET switch including a single primary transfer transistor. The bulk of the transfer transistor is coupled to a differential logic sense circuit that is designed to establish a pseudo low-potential power rail. The logic sense circuit is coupled to the two transfer nodes and a standard low-potential power rail. It compares the potentials associated with the transfer node signals and the low-potential rail and selects the one with the lowest potential to establish the potential of the pseudo low-potential rail. The logic sense circuit provides for active selection of the lowest potential element, including under very small undershoot conditions.
    Type: Grant
    Filed: October 4, 1999
    Date of Patent: May 22, 2001
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Trenor F. Goodell, Myron J. Miske
  • Patent number: 6229365
    Abstract: At the last stage of a level converter that provides an internal signal to an internal signal output node, MOS transistors that are rendered conductive alternatively are provided as current source transistors. These additional MOS transistors are selectively rendered conductive according to the voltage level of, for example, a bonding pad. The charging/discharging current towards the internal node can be adjusted. Accordingly, the rising time and falling time of the internal signal can be constantly made equal. Thus an input/output circuit that can provide a signal at a proper timing even when the operating environment such as the system power supply voltage changes can be implemented.
    Type: Grant
    Filed: December 1, 1997
    Date of Patent: May 8, 2001
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masayuki Iketani, Shigeki Ohbayashi
  • Patent number: 6225844
    Abstract: An output buffer circuit includes first and second buffers, a slew rate control section and a first resistor. The first buffer has a pull-up transistor and a pull-down transistor to output an output signal to an output section from a first node located between the pull-up and pull-down transistors. The second buffer has complementary transistors and is provided in a front portion of the first buffer. A second node is located between the complementary transistors to be connected to the first node. The first resistor is connected between the second node and the output section to function as an output resistor of the second buffer. The first buffer complementarily operates in response to first and second control resistor respectively inputted to control electrodes of the pull-up and pull-down transistors, to output the output signal to the output section.
    Type: Grant
    Filed: April 15, 1999
    Date of Patent: May 1, 2001
    Assignee: NEC Corporation
    Inventor: Tsukasa Fujiwara
  • Patent number: 6204652
    Abstract: A motor vehicle electrical system has at least one apparatus for regulating the power supply voltage of an electrical load which has a nominal or rated supply voltage. The regulating apparatus is supplied by a variable value unidirectional voltage source. The apparatus includes an oscillator for generating a rectangular control signal having a cyclic ratio which varies with the value of the unidirectional voltage when the latter is above a given threshold value. The apparatus also includes an interrupter controlled by the control signal and connected in series with the load across the voltage source. Each voltage regulating apparatus further includes an inductance connected in series with the load, and a component with unidirectional conduction in parallel with the series connected load and inductance.
    Type: Grant
    Filed: March 22, 2000
    Date of Patent: March 20, 2001
    Assignee: Valeo Vision
    Inventors: Pierre Albou, Jean Paul Charret, Joel Leleve
  • Patent number: 6194945
    Abstract: A receiver circuit has a high threshold of 3.3÷2 volts and maximum noise margin. This is achieved by making two transistors in the receiver have channel resistances, under the condition whereas input line carries 3.3÷2 volts and a control line carries 0 volts, that generate an output signal as a first resistance ratio which when multiplied by a supply voltage equals 3.3÷2 volts. Further, the receiver also has a low threshold of 2.5÷2 volts and maximum noise margin. This is achieved by making the above two transistors, plus two other transistors in the receiver, have respective channel resistances under the condition where the input line carries 2.5÷2 volts and the control signal line carries 3.3 volts, that generate the output signal as a second resistance ratio which when multiplied by the supply voltage again equals 3.3÷2 volts.
    Type: Grant
    Filed: November 2, 1995
    Date of Patent: February 27, 2001
    Assignee: Unisys Corporation
    Inventor: Hamid Bahramzadeh
  • Patent number: 6194951
    Abstract: A voltage UA that can be measured at a junction point between a load and a limit switch when the load is disconnected is compared with a predetermined threshold value W. The limit switch is turned on and off with a predetermined current associated with shallow turn-on and turn-off edges when UA<W, or is turned on and off with a higher current associated with steep turn-on and turn-off edges when UA>W.
    Type: Grant
    Filed: March 16, 2000
    Date of Patent: February 27, 2001
    Assignee: Siemens Aktiengesellschaft
    Inventor: Franz Allmeier
  • Patent number: 6194952
    Abstract: When a power supply terminal (10) is grounded, a circuit (101) is in the OFF state, and a high potential is transferred from a circuit (3) to a bus line (BL), the high potential is transferred to a node (100) via the source of a transistor (P1), back gate (Nw), and transistor (P2). A NAND circuit (NA1) always outputs a control signal (VGP) of a level equal to the node (100) to the gate of the transistor (P1) to turn non-conductive the transistor (P1). Hence, a current path from a terminal (B) to a terminal (A) or from the terminal (B) to the back gate (Nw) is cut off to prevent wasteful current consumption.
    Type: Grant
    Filed: May 5, 1999
    Date of Patent: February 27, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Hiroshi Shigehara
  • Patent number: 6181172
    Abstract: A voltage detector circuit discriminates between a 13 volt Programming signal and a 6 volt signal without creating a field across the gate oxide of a sensing transistor in excess of 7.0 MegaV/cm. A PMOS transistor has a source terminal and a substrate terminal connected, both connected to the input terminal, A gate terminal is connected to a VCC voltage level. A shunt NMOS transistor has a drain terminal connected to the drain terminal of the PMOS transistor and a source terminal connected to a ground terminal. A gate terminal of the shunt NMOS transistor is connected to the VCC voltage level. The NMOS transistor is turned on to provide a shunt resistance between the drain terminal of the PMOS transistor and ground. A drain terminal of a series NMOS transistor is connected to the drain terminal of the PMOS transistor. A gate terminal of the series NMOS transistor is connected to VCC. The source terminal of the series NMOS transistor is connected to a sensing output terminal.
    Type: Grant
    Filed: December 27, 1995
    Date of Patent: January 30, 2001
    Assignee: Philips Electronics North America Corp.
    Inventor: John M. Callahan
  • Patent number: 6177818
    Abstract: An off-chip driver circuit including an enhancement PFET, a depletion PFET, a depletion NFET and an enhancement NFET connected in series. The large enhancement PFET and large enhancement NFET turn off the OCD in tri-state and to turn off the unused half of the OCD to prevent overlap current when driving a ‘0’ or a ‘1’. A first gate signal is applied to the gate of the enhancement PFET and a second gate signal is applied to the enhancement NFET. A fixed voltage is connected to the gate of the depletion NFET and ground to gate of the depletion PFET. An output signal is obtained from a node between the depletion PFET and depletion NFET devices. In another embodiment, a reflection/overshoot sensor 60 is added. The output of sensor is connected to the body of a depletion PFET and an NFET. The feedback from sensor is such that the threshold voltage of the depletion devices are made more positive if the sensor detects that the output is being over-driven.
    Type: Grant
    Filed: April 30, 1999
    Date of Patent: January 23, 2001
    Assignee: International Business Machines Corporation
    Inventors: Claude L. Bertin, Anthony R. Bonaccio, Howard L. Kalter, Thomas M. Maffitt, Jack A. Mandelman, William R. Tonti
  • Patent number: 6177819
    Abstract: The invention provides an IC driver circuit having an adjustable trip point. The driver circuit automatically adjusts the trip point of the circuit based on the state of the output signal (and thus, by inference, on the state of the input signal), by using first and second switches to couple and decouple secondary pullup and pulldown circuits. In one embodiment, this coupling/decoupling also ensures that the output signal has a shorter rise/fall time than the input signal. Therefore, the output signal reaches a midpoint voltage level (i.e., VCC/2) before the input signal reaches the same level. In a sense, the driver circuit has a negative propagation delay. In a second embodiment, the first and second switches are controlled to ensure low noise-sensitivity, rather than high speed. In another embodiment, the driver circuit can be controlled for either high speed or noise insensitivity.
    Type: Grant
    Filed: April 1, 1999
    Date of Patent: January 23, 2001
    Assignee: Xilinx, Inc.
    Inventor: Andy T. Nguyen
  • Patent number: 6177826
    Abstract: A Silicon-On-Insulator (SOI) CMOS circuit comprises a plurality of PMOS transistors connected in series to each other, each of the plurality of PMOS transistors having its body and gate connected to each other, and at least an NMOS transistor connected to one of the plurality of PMOS transistors, the NMOS transistor having its body connected to a low reference potential having a value of ground. The SOI CMOS circuit can further comprise a plurality of potential limiting circuits each connected between the body and gate of each of the plurality of PMOS transistors, for setting a lower limit of the potential of the body of each of the plurality of PMOS transistors to a voltage between a high reference potential and a potential obtained by subtracting a built-in potential from the high reference potential.
    Type: Grant
    Filed: April 2, 1998
    Date of Patent: January 23, 2001
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Koichiro Mashiko, Kimio Ueda, Yoshiki Wada
  • Patent number: 6169430
    Abstract: A CMOS imager is arranged in a plurality of rows and columns with a gain compensation circuit supplied for each of the column. The gain compensation circuit has a first source follower circuit that employs majority carriers of a first polarity yielding a first voltage gain, and a second source follower circuit employing majority carriers of second polarity opposite the first polarity yielding a voltage gain that is essentially the opposite of the first voltage gain variation as compared to the input voltage. The input to the second source follower circuit that is electrically coupled to the output of the second source follower circuit resulting in a gain compensation between the first and second source follower circuits. A selection circuit is configured to enable the gain compensation circuit upon activation of a column select signal.
    Type: Grant
    Filed: April 14, 1998
    Date of Patent: January 2, 2001
    Assignee: Eastman Kodak Company
    Inventor: Weize Xu
  • Patent number: 6130563
    Abstract: An output driver circuit capable of driving its data output terminal to a digital logic level high, capable of driving its data output terminal to a digital logic level low, and capable of tristating its data output terminal has an output stage comprising a pullup transistor and a pulldown transistor. The two pullup and pull down transistors are coupled in series between two drive transistor circuits. In one aspect of the invention, the pullup and pulldown drive transistor circuits provide momentary low impedance connection of the pullup and pulldown transistors to the respective pullup and pulldown voltage sources during the initial switching waveforms of the digital signal. After the initial switching of the digital signal, the pullup and pulldown drive transistor circuits provide precise V.sub.OH and V.sub.OL voltage output levels and provide high impedance filtering of voltage supply line and ground line noise.
    Type: Grant
    Filed: September 10, 1997
    Date of Patent: October 10, 2000
    Assignee: Integrated Device Technology, Inc.
    Inventors: David J. Pilling, Raymond Chu
  • Patent number: 6130549
    Abstract: An output driver for an integrated semiconductor chip overcomes voltage fluctuations at connections of a supply voltage of the semiconductor chip generated by a rapid-switching output driver. The output driver includes a switching circuit which is connected to the supply voltage and contains two switching transistors, as well as a regulating circuit for voltage-dependent regulation of switching characteristics of the switching circuit. As a result of the regulating circuit, the switching characteristics of at least one transistor of the switching circuit are regulated in such a way as to counteract voltage fluctuations arising at the connections to the supply voltage through the switching process of the switching circuit.
    Type: Grant
    Filed: July 1, 1999
    Date of Patent: October 10, 2000
    Assignee: Siemens Aktiengesellschaft
    Inventor: Martin Buck
  • Patent number: 6127857
    Abstract: In order to prevent an output offset voltage from occurring because of a relative difference of threshold voltage Vth between NMOS and PMOS in transmission of dc voltage, a semiconductor integrated circuit is constructed in a circuit configuration comprising a first depletion-mode N-channel MOS transistor and a first depletion-mode P-channel MOS transistor, a gate of each transistor being connected to an input terminal and a source of each transistor being connected to an output terminal, a second depletion-mode N-channel MOS transistor having W/L equal to that of the first depletion-mode P-channel MOS transistor, a drain of the transistor being connected to the output terminal and a gate and a source of the transistor being connected both to a lower-voltage-side power supply, and a second depletion-mode P-channel MOS transistor having W/L equal to that of the first depletion-mode P-channel MOS transistor, a drain of the transistor being connected to the output terminal and a gate and a source of the transist
    Type: Grant
    Filed: July 2, 1998
    Date of Patent: October 3, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Katsuhisa Ogawa, Tadahiro Ohmi, Tadashi Shibata
  • Patent number: 6118310
    Abstract: The present invention is generally directed to a PVT compensated variable impedance output driver for driving a signal through a signal pad on a semiconductor device. In accordance with one aspect of the present invention, the output driver includes a plurality of p-channel field effect transistors (PFETs) electrically connected in parallel. A source node of each of the plurality of PFETs are electrically connected together, and a drain node of each of the plurality of PFETs are electrically connected together. The driver further includes a plurality of n-channel field effect transistors (NFETs) electrically connected in parallel. A source node of each of the plurality of NFETs are electrically connected together and a drain node of each of the plurality of NFETs are electrically connected together.
    Type: Grant
    Filed: November 4, 1998
    Date of Patent: September 12, 2000
    Assignee: Agilent Technologies
    Inventor: Gerald L. Esch, Jr.
  • Patent number: 6114840
    Abstract: Signal transfer devices enable multiple processors to act as drivers or receivers of signals which can transition from an invalid state to a valid state and then return to the invalid state in one clock cycle. The preferred signal transfer device includes a bus line, a plurality of bus drivers electrically connected to the bus line for initiating wired-OR signal transitions and at least one self-timed booster circuit electrically connected to the bus line. The self-timed booster circuit includes a first field effect transistor electrically connected in series between the bus line and a first reference potential and a second field effect transistor electrically connected in series between the bus line and a second reference potential. A timing circuit is also provided as a plurality of inverters which are electrically coupled in series. The timing circuit, which has an input electrically coupled to the bus line, performs a boolean inversion of the signals on the bus line after a first delay.
    Type: Grant
    Filed: September 17, 1998
    Date of Patent: September 5, 2000
    Assignee: Integrated Device Technology, Inc.
    Inventors: Michael Francis Farrell, Paul Edwin Platt
  • Patent number: 6114885
    Abstract: Integrated driver circuits include a pull-up circuit having a first plurality of PMOS pull-up transistors therein which are selectively enabled by a first multi-bit impedance control signal. This first multi-bit impedance control signal is a function of a first variable resistance device. A pull-down circuit is also provided. The pull-down circuit has a first plurality of NMOS pull-down transistors therein which are selectively enabled by a second multi-bit impedance control signal. This second multi-bit impedance control signal is a function of a resistance of a second variable resistance device. The pull-up circuit and pull-down circuit have commonly connected outputs. In particular, the pull-up circuit has a first impedance which is a function of a digital value of the first multi-bit impedance control signal and the pull-down circuit has a second impedance which is a function of a digital value of the second multi-bit impedance control signal.
    Type: Grant
    Filed: August 24, 1998
    Date of Patent: September 5, 2000
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Seung-Kweon Yang, Yong-Jin Yoon
  • Patent number: 6114898
    Abstract: An output drive circuit within a semiconductor integrated circuit is formed into a push-pull configuration by field effect transistors, the bias of which is controlled to establish the output impedance of the driver at a desired value.
    Type: Grant
    Filed: April 6, 1998
    Date of Patent: September 5, 2000
    Assignee: Advantest Corporation
    Inventor: Toshiyuki Okayasu
  • Patent number: 6111456
    Abstract: A semiconductor circuit comprises an I-type of NMOS transistors N15 and N16 connected between a power supply voltage VDD and a ground electrode. The gate electrode of the NMOS transistor N15 is set to a reference voltage VREF that is lower than the power supply voltage VDD. The drain voltage VD of the NMOS transistor N16 is almost equal to the reference voltage VREF, and the NMOS transistor N16 acts in a linear region. Accordingly, the NMOS transistor N16 acts in the same manner as the resistor element and has no influence on change of the concentration of the diffusion resistor or the power supply voltage VDD.
    Type: Grant
    Filed: February 25, 1998
    Date of Patent: August 29, 2000
    Inventors: Hidetoshi Saito, Shigeru Atsumi, Akira Umezawa
  • Patent number: 6100725
    Abstract: A driver circuit (12) having a reduced propagation delay is provided. The driver circuit (12) includes a first device (56) having an input and operable to switch a supply voltage to a load (14). A second device (54) having an output coupled to the input of the first device (56), operable to turn on the first device upon receipt of a first signal. A third device (66) having an output coupled to the input of the first device (56), operable to turn off the first device upon receipt of a second signal. A kick start circuit (30) coupled to the input for the first device (56), the input for the second device (54), and the input for the third device (66), operable to generate a threshold voltage on the first device (56), the second device (54), and the third device (66). The kick start circuit (30) operable to produce a threshold voltage that is just below the voltage in which the first device (56), the second device (54), and the third device (66) turn on, or conduct.
    Type: Grant
    Filed: March 31, 1998
    Date of Patent: August 8, 2000
    Assignee: Texas Instruments Incorporated
    Inventors: Cecil J. Aswell, Eugene G. Dierschke
  • Patent number: 6097238
    Abstract: A ramping circuit gradually applies an erasing voltage to a memory cell. Within the ramping circuit an NMOS transistor is disclosed which gradually supplies the erasing voltage to the memory cell in response to an external ramping voltage. The NMOS transistor supplies the erasing voltage until the body effect loss voltage of the transistor limits a maximum erasing voltage that the NMOS transistor can supply. The specification then discloses a PMOS transistor which operates to supply the erasing voltage to the memory cell when the NMOS transistor can no longer do so. The PMOS transistor is connected to control circuitry which keeps the PMOS transistor inactive until the output voltage of the NMOS transistor is limited by its body effect voltage loss.
    Type: Grant
    Filed: January 10, 1997
    Date of Patent: August 1, 2000
    Assignee: Xilinx, Inc.
    Inventor: Shi-dong Zhou
  • Patent number: 6087880
    Abstract: A level shifter provided with a first inverter for shifting a high logic level of an input signal, a second inverter for shifting a low logic level of the input signal, a first output transistor for supplying a high voltage to an output terminal by an output voltage of the first inverter, and a second output transistor for supplying a low voltage to the output terminal by an output voltage of the second inverter which controls the supply of the high voltage of the first inverter and the supply of the low voltage of the second inverter so as to realize stable operation even with a low power supply voltage.
    Type: Grant
    Filed: January 21, 1997
    Date of Patent: July 11, 2000
    Assignee: Sony Corporation
    Inventor: Shunsuke Takagi
  • Patent number: 6066973
    Abstract: An input circuit is made up of an external signal input portion which inputs an external signal, a voltage level converting circuit which has an input terminal for inputting a signal from the external signal input circuit and which has an output terminal for outputng the signal to the internal circuit after a voltage level was converted, a first power supply terminal which has a first potential for driving the voltage level converting circuit, a second power supply terminal which has a second potential for driving the voltage level converting circuit, and a noise control portion which couples to the input terminal of the voltage level converting circuit, which controls a noise from the first power supply terminal and/or the second power supply terminal, and which has a first capacitor. Accordingly, the input circuit could be applied the stable signal to the internal circuit.
    Type: Grant
    Filed: March 31, 1998
    Date of Patent: May 23, 2000
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Yoshimasa Sekino, Katuaki Matui
  • Patent number: 6064228
    Abstract: The device for generating digital signal levels can be used for signals of various logic standards. A voltage terminal for feeding an external reference voltage is provided as well as an internal voltage generator. An internal reference voltage of the voltage generator can be selectively connected to the device via a switch. The switch is actuated by a level converter. Coupling elements prevent faults caused by the supply voltage.
    Type: Grant
    Filed: June 10, 1998
    Date of Patent: May 16, 2000
    Assignee: Siemens Aktiengesellschaft
    Inventors: Christian Sichert, Robert Kaiser, Norbert Wirth
  • Patent number: 6060940
    Abstract: A CMOS output stage for providing stable quiescent current. The output stage includes a circuit that relates the quiescent current to the channel geometry of a power NMOS transistor and of an NMOS reference transistor of a reference current source. This configuration removes the dependency of the quiescent current on a power PMOS transistor used in the CMOS output stage, the threshold voltage of which may drift over time under high current and voltage operation, and adversely affects quiescent current stability.
    Type: Grant
    Filed: April 14, 1998
    Date of Patent: May 9, 2000
    Assignee: SGS-Thomson Microelectronics S.r.l.
    Inventor: Giorgio Chiozzi
  • Patent number: 6054876
    Abstract: A buffer circuit includes a signal input terminal and a signal output terminal. A first operational amplifier includes a differential amplifier circuit having an input transistor of an N-channel MOS type. The first operational amplifier has an inverting input terminal and an output terminal connected to each other. The first operational amplifier has a non-inverting input terminal connected to the signal input terminal. A second operational amplifier includes a differential amplifier circuit having an input transistor of a P-channel MOS type. The second operational amplifier has an inverting input terminal and an output terminal connected to each other. The second operational amplifier has a non-inverting input terminal connected to the signal input terminal.
    Type: Grant
    Filed: July 17, 1998
    Date of Patent: April 25, 2000
    Assignee: Denso Corporation
    Inventors: Masakiyo Horie, Hirofumi Isomura, Takuya Harada
  • Patent number: 6052019
    Abstract: A bus switch has an n-channel bus-switch transistor that connects an input-bus signal to an output bus. A gate protection circuit prevents undershoots on the inputs from coupling to the output when the bus switch isolates the buses. The gate of the bus-switch transistor is driven to ground during isolation mode. When a high-to-low transition of the input-bus signal is detected, a pulse generator generates a pulse. The pulse disconnects the gate from ground. A connecting n-channel transistor with its gate connected to ground connects the gate to the input-bus signal when the undershoot pulls the input-bus signal below ground. Internal circuitry is isolated from the below-ground gate by an isolating n-channel transistor that has its gate driven by the input-bus signal during the pulse. A substrate bias generator is used for N-well processes, but P-well processes use a well protection circuit. The P-well under the bus-switch transistor is disconnected from ground during the generated pulse.
    Type: Grant
    Filed: October 29, 1998
    Date of Patent: April 18, 2000
    Assignee: Pericom Semiconductor Corp.
    Inventor: David Kwong
  • Patent number: 6046621
    Abstract: A differential signal generator for generating a true/complement output signal pair in response to a single-ended input signal is disclosed. The differential signal generator includes an input stage that generates a true/complement intermediate signal pair in response to the input signal, and first and second inverters that generate the output signal pair in response to the intermediate signal pair. The first and second inverters have dynamic beta ratios that change in response to the input signal. This is accomplished by coupling a transistor in the first inverter to ground and decoupling a transistor in the second inverter from ground when the input signal has a high value, and decoupling the transistor in the first inverter from ground and coupling the transistor in the second inverter to ground when the input signal has a low value. As a result, the output signal pair cross each other at a predetermined cross-point although the intermediate signal pair does not.
    Type: Grant
    Filed: September 26, 1997
    Date of Patent: April 4, 2000
    Assignee: Advanced Micro Devices, Inc.
    Inventor: Matthew P. Crowley
  • Patent number: 6043699
    Abstract: A level shift circuit reduced in a circuit area and conversion delay when converting a signal level, capable of operating at a high speed, expanded in the range of the operatable voltage, and capable of operating at a low voltage, including a first transistor connected between a voltage Va source and an output terminal, a second transistor connected between a voltage Vc source and an output terminal, a third transistor connected between a voltage Vc source and a gate of the second transistor, a fourth transistor connected between a voltage Va source and the gate of the second transistor, a fifth transistor connected between the ground and the output terminal, and a sixth transistor connected between the ground and the gate of the second transistor, wherein a connection point of an output terminal and the first, second, and fifth transistors is connected to a gate of the third transistor, gates of the fourth and fifth transistors are connected to an input terminal, and an inverted signal of an input signal to
    Type: Grant
    Filed: November 3, 1998
    Date of Patent: March 28, 2000
    Assignee: Sony Corporation
    Inventor: Yasuhide Shimizu
  • Patent number: 6043691
    Abstract: A pulse shaper circuit includes a buffer having an input, an output and two supply connections. A controllable first switch is connected between one of the supply connections and a first supply potential, a controllable second switch is connected between the other supply voltage connection and a second supply potential, a controllable third switch is connected between the output of the buffer and the first supply potential and a controllable fourth switch is connected between the output of the buffer and the second supply potential. A control device for the switches is connected to the output of the buffer and produces a first control pulse of a specific duration at the occurrence of first edges of a signal present at the output of the buffer and a second control pulse of a specific duration at the occurrence of second edges. The first control pulse changes over the first switch from the ON state to the OFF state and the fourth switch from the OFF state to the ON state.
    Type: Grant
    Filed: September 25, 1998
    Date of Patent: March 28, 2000
    Assignee: Siemens Aktiengesellschaft
    Inventors: Bret Johnson, Ralf Schneider
  • Patent number: 6040732
    Abstract: A switched-transconductance circuit for use in a multiplexer circuit includes integrated T-switches to provide isolation between each of the differential voltage inputs of a transconductance stage and: (1) a respective differential current output of the transconductance stage, and (2) the opposite polarity voltage input of the transconductance stage. Each of a pair of first switches, which are enabled only when the transconductance circuit is disabled, is connected between a differential current output of the transconductance stage and a circuit ground. Each of a pair of second switches, e.g., cascode transistors, which are biased to be turned on only when the transconductance circuit is enabled, is coupled between the output of the transconductance stage and an output of the transconductance circuit. A third switch is connected between a common-emitter node of a differential pair of input transistors included in the transconductance stage and a circuit ground.
    Type: Grant
    Filed: April 9, 1997
    Date of Patent: March 21, 2000
    Assignee: Analog Devices, Inc.
    Inventor: A. Paul Brokaw
  • Patent number: 6040729
    Abstract: An output buffer translates digital input signals which toggle between ground and V.sub.DDL to signals which toggle between ground and V.sub.DDH. The technology dielectric breakdown voltage limit is less than the magnitude of V.sub.DDH, such that use of a traditional output stage would subject transistors' dielectrics to voltages which exceed their dielectric breakdown limit, and would thus be damaged. Predrive circuits (40, 50) control output stage (70) transistors' (72, 78) gates, and voltage dropping circuits control output stage (70) transistors (74, 76). These control signals are generated specifically to maximize output stage transistor drive strengths, thereby minimizing output stage size. Output buffer functions when V.sub.DDL =V.sub.DDH, and its performance is V.sub.DDL independent. Temperature compensation is incorporated into the output buffer by deliberately offsetting temperature effects on output stage transistor drive strengths.
    Type: Grant
    Filed: August 25, 1997
    Date of Patent: March 21, 2000
    Assignee: Motorola, Inc.
    Inventors: Hector Sanchez, Jose M. Alvarez, Joshua Siegel, Carmine Nicoletta
  • Patent number: 6031416
    Abstract: A CMOS elementary cell of the first order for time-continuous analog filters with non-linearity compensation, is connected between a first supply voltage reference and a second voltage reference. The cell is of a type which comprises at least a first MOS transistor having its conduction terminals connected to the first supply voltage reference and to an output terminal, and having a control terminal connected to an input terminal of the first order CMOS elementary cell. The cell further comprises a second MOS transistor in diode configuration, and an equivalent capacitor, both connected to the output terminal of the first order CMOS elementary cell. The second, diode-connected MOS transistor and the equivalent capacitor act as a load for the first MOS transistor. The first MOS transistor operates as a drive transistor operatively tied to an input voltage signal being supplied to the input terminal of the first order CMOS elementary cell. A second order filter CMOS elementary cell is similarly connected.
    Type: Grant
    Filed: April 27, 1998
    Date of Patent: February 29, 2000
    Assignee: STMicroeletronics S.r.l.
    Inventors: Andrea Baschirotto, Ugo Baschirotto, Guido Brasca, Rinaldo Castello
  • Patent number: 6008683
    Abstract: A loading device for use in a tester for testing a semiconductor integrated circuit device (DUT) includes a programmable voltage source for providing a selected voltage at an output terminal thereof and multiple resistive elements each having at least a first state, in which the resistive element is conductive, and a second state, in which the resistive element is substantially non-conductive. The resistive elements are connected as a two-terminal network between the output terminal of the programmable voltage source and a tester pin for connection to a pin of the DUT. A selection device selects the state of each resistive element, whereby the resistance between the output terminal of the programmable voltage source and the tester pin can be selectively varied.
    Type: Grant
    Filed: October 31, 1997
    Date of Patent: December 28, 1999
    Assignee: Credence Systems Corporation
    Inventor: Garry C. Gillette
  • Patent number: 5999034
    Abstract: A circuit for controlling a voltage provided to a switching transistor in a voltage conversion buffer which drives a high voltage output with low voltage transistors. The circuit has two elements to it. First, a pull-up circuit pulls the gate of the switching transistor to a high voltage level in response to a first state of a control logic signal. Second, a pull-down circuit pulls the gate of the switching transistor down to an intermediate voltage in response to a second state of the control logic signal. The intermediate voltage is set to be less than the high voltage by no more than approximately the low voltage amount. The pull-down circuit is a transistor connected to a low voltage source, which limits the pull-down voltage. Additional transistors are provided to turn on and off the pull-down transistor, with a circuit connected to a fail-safe low voltage source being used to protect these transistors.
    Type: Grant
    Filed: January 28, 1998
    Date of Patent: December 7, 1999
    Assignee: Sun Microsystems, Inc.
    Inventors: Gajendra P. Singh, Vidyasager Ganesan
  • Patent number: 5982207
    Abstract: An output buffer of an integrated circuit arranged to be energised from a supply source providing predetermined potentials to supply conductors of the integrated circuit, comprises a potential divider R.sub.1, R.sub.2, R.sub.3 to define reference levels V.sub.1, V.sub.2 having a reduced swing compared to the supply levels V.sub.DD and 0, which reference levels are transferred to an output node V.sub.out, so that the reference potentials are unaffected by the loading of the output node, which the reduced voltage swing reduces pick-up caused by switching of the output buffer.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: November 9, 1999
    Assignee: Mitel Semiconductor Limited
    Inventor: David J Wilcox
  • Patent number: 5977892
    Abstract: An offset cancellation circuit(1) for an analog switch(10) is provided which substantially reduces the offset voltage induced by the analog switch circuit. The circuit(1) comprising a second P-channel transistor(2) and a third N-channel transistor(4) connected to each other in series, the drains of the second P-channel transistor and the third N-channel transistor being connected to the output terminal; a second N-channel transistor(3) and a third P-channel transistor(5) connected to each other in series, the drains of the second N-channel transistor and the third P-channel transistor being connected to the output terminal; the gate of the second P-channel transistor is connected to the gate of the N-channel transistor; and the gate of the second N-channel transistor is connected to the gate of the P-channel transistor.
    Type: Grant
    Filed: May 16, 1996
    Date of Patent: November 2, 1999
    Assignee: Motorola, Inc.
    Inventors: Yuichi Nakatani, Satoshi Takahashi, Masami Aiura
  • Patent number: 5973549
    Abstract: An input buffer in a semiconductor device reduces power consumption by decreasing variation of an operation bias voltage. The semiconductor device has an input buffer driving circuit with an inversion circuit at its output, both of which circuits drive the input buffer to cause it to output a power voltage V.sub.dd or a ground voltage V.sub.ss. The driving circuit outputs a "high ground" voltage when an input voltage V.sub.in is 1.685 volts, and a "low power" voltage when V.sub.in is 1.285 volts. The device also has a circuit that generates reference potentials having a "low power" voltage and "high ground" voltage needed by the driving circuit's power voltage terminal and ground voltage terminal.
    Type: Grant
    Filed: October 21, 1997
    Date of Patent: October 26, 1999
    Assignee: Hyundai Electronics Industrial Co., Ltd.
    Inventor: Jong Hak Yuh
  • Patent number: 5963076
    Abstract: In a circuit (10), a first N-FET (N1) and a second N-FET (N2) are coupled serially between a node (15) and ground (93). The circuit (10) accommodates a first excursion (85) of a first signal (IN) at the gates of the first N-FET (N1) which is higher than the maximum allowable drain-source voltage for N-FETs. The voltage of a second signal (OUT) between the node (15) and ground (93) is distributed across the first and the second N-FETs (N1, N2). The gate voltage of the second N-FET (N2) is not constant, but controlled by a control circuit (20) receiving signals the first signal (IN) and, optionally, the second signal (OUT). With the variation of the gate voltage for the second N-FET (N2), the size of both transistors (N1, N2) can be reduced and the fall time (T.sub.F) of the second signal (OUT) can be reduced.
    Type: Grant
    Filed: April 14, 1997
    Date of Patent: October 5, 1999
    Assignee: Motorola, Inc.
    Inventors: Joseph Shor, Mark Yosefin, Dan Mauricio Bruck
  • Patent number: 5963063
    Abstract: A waveform shaping circuit free of error in the hold capacitor due to parasitic capacitance of the MOSFET transistor.
    Type: Grant
    Filed: August 26, 1997
    Date of Patent: October 5, 1999
    Assignee: Texas Instruments Incorporated
    Inventor: Fujihiko Sugihashi
  • Patent number: 5963080
    Abstract: A bus switch for transferring logic signals between nodes without the problems associated with undershoot conduction. The bus switch is an FET switch including a single primary transfer transistor. The bulk of the transfer transistor is coupled to a bulk regulating circuit including a pseudo low-potential power rail. The pseudo low-potential rail is coupled to one arbiter circuit associated with one of the two circuit transfer nodes and a second arbiter circuit associated with the other of the two transfer nodes. The arbiter circuits are coupled to their respective nodes or pads and to a common low-potential supply rail. The arbiter selects for coupling to the pseudo low-potential rail the signal of the lower potential between that at the pad and that of the low-potential rail. This arrangement ensures that there will be no parasitic conduction of the transfer transistor during undershoot conditions.
    Type: Grant
    Filed: December 23, 1998
    Date of Patent: October 5, 1999
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Myron J. Miske, Trenor F. Goodell
  • Patent number: 5959474
    Abstract: An output buffer circuit comprising a pull-up transistor, a pull-down transistor coupled to the pull-up transistor, a first voltage source for supplying a driving voltage, a second voltage source for supplying a reference voltage, a device for comparing the driving voltage with the reference voltage, a driving voltage detector for producing a signal in response to operation of the comparing device, first and second pull-up driving buffers, the first and second pull-up driving buffers being activated according to the signal from the driving voltage detector, the pull-up transistor being driven by one of the pull-up driving buffers, and first and second pull-down driving buffers, the first and second pull-down driving buffers being activated according to the signal from the driving voltage detector, and the pull-down transistor being driven by one of the pull-down driving buffers.
    Type: Grant
    Filed: December 30, 1997
    Date of Patent: September 28, 1999
    Assignee: LG Semicon Co., Ltd.
    Inventors: Jong Hoon Park, Tae Hyung Jung
  • Patent number: 5959475
    Abstract: An analog video buffer utilizes a complementary push-pull CMOS source follower video buffer with a feedback driver. The CMOS source follower provides a low impedance output node with high driving capabilities, high switching speed, and rail-to-rail linearity and the feedback driver isolates the output node from the feedback needed for the design of the video buffer to provide a transient response without ringing or overshoot.
    Type: Grant
    Filed: January 13, 1998
    Date of Patent: September 28, 1999
    Assignee: Xerox Corporation
    Inventor: Mehrdad Zomorrodi
  • Patent number: 5959490
    Abstract: A translation circuit for mixed logic voltage signals is comprised of a first pair of self-biasing common-mode level shifters for receiving positive and negative polarity input signals respectively of a balanced input signal, each level shifter having a control input for receiving a ratio control signal, and having first level shifter nodes for providing the same polarity output signals, a second pair of self-biasing common-mode level shifters, each connected in parallel with a corresponding variable ratio level shifter, the second pair of level shifters having fixed level shift ratios, a circuit connected to level shifter nodes of the second pair of level shifters for providing and storing a signal which is a sum of voltages appearing at the level shifter nodes, and a circuit for applying the stored signal to the control inputs.
    Type: Grant
    Filed: December 10, 1997
    Date of Patent: September 28, 1999
    Assignee: PMC-Sierra Ltd.
    Inventors: Anthony B. Candage, George Deliyannides
  • Patent number: 5952865
    Abstract: The circuit is for translating a switching signal disposed between ground level and Vdd to a translated switching signal disposed between first and second voltages Vhsrc and Vhstrap. The circuit includes a bistable circuit formed by two branches which include two nMOS transistors the sources of which are connected to ground and are controlled, respectively, by a switching-on signal and by a switching-off signal derived from the switching signal by means of a buffer and an inverter, respectively. Two pMOS transistors having their sources at the voltage Vhstrap and the drain of one connected to the gate of the other output the translated switching signal at one of their drains. Two further pMOS transistors having gates at the first voltage Vhsrc are interposed between the two nMOS transistors and the two pMOS transistors.
    Type: Grant
    Filed: February 7, 1997
    Date of Patent: September 14, 1999
    Assignee: STMicroelectronics, S.R.L.
    Inventor: Luca Rigazio
  • Patent number: 5939929
    Abstract: An output driver circuit for use with ethernet repeaters is disclosed which produces a symmetric (low jitter) output signal in response to an input signal. The circuit further exhibits low ground bounce by maintaining an output level swing of between 1.5 and 1.8 volts. When not transmitting, the driver provides power savings by maintaining a half level signal at its output.
    Type: Grant
    Filed: October 27, 1997
    Date of Patent: August 17, 1999
    Assignee: Advanced Micro Devices, Inc.
    Inventor: Vadim Tsinker
  • Patent number: 5939932
    Abstract: A high-output voltage generating circuit that prevents transistor breakdown includes first and second switching circuits coupled to each other at a first common gate, the first common gate being connected to a first control signal, and the first and second switching circuits being connected to a common input signal; third and fourth switching circuits coupled to each other at a second common gate, the second common gate being connected to a second control signal; a signal output unit having first and second transistors coupled to each other at a third common gate, the third common gate being connected to the second control signal; a third transistor, coupled to a first voltage, receiving a first signal at a gate from the first switching circuit; a fourth transistor, coupled to the third transistor, receiving a second signal from the third switching circuit at a gate, the fourth transistor being coupled to the first transistor of the signal output unit; a fifth transistor, coupled to the second transistor of t
    Type: Grant
    Filed: August 29, 1997
    Date of Patent: August 17, 1999
    Assignee: LG Semicon Co., Ltd.
    Inventor: Won-Kee Lee
  • Patent number: 5939937
    Abstract: An output driver circuit having an output coupled to a resistive termination load comprises: a dual gate pFET device including source and drain transistors, each transistor respectively having a gate, source, and drain, the source transistor source coupled to a voltage source V, the source transistor drain coupled to the drain transistor source, the drain transistor drain coupled to the output of the driver circuit; a dual gate nFET device including source and drain transistors, each transistor respectively having a gate, source and drain, the source transistor source coupled to a ground potential, the source transistor drain coupled to the drain transistor source, the drain transistor drain coupled to the output of the driver circuit; first and second switches, coupled to the source transistor gate of the pFET device and the nFET device, respectively, for turning on and off current flow from the voltage source V through the source transistor of the pFET device and to the ground potential through the source t
    Type: Grant
    Filed: September 29, 1997
    Date of Patent: August 17, 1999
    Assignee: Siemens Aktiengesellschaft
    Inventor: Hartmud Terletzki
  • Patent number: 5939923
    Abstract: A selectable low power signal line (10) is provided that includes a driver circuit (12) connected to receive an input signal for transmission and to receive a mode select signal (SELECT). The driver circuit (12) has a low power mode and a full power mode selectable responsive to the mode select signal (SELECT). The driver circuit (12) is operable, when in the full power mode, to drive an output signal at a full swing of the input signal. When in the low power mode, the driver circuit (12) is operable to drive the output signal at a fraction of the full swing of the input signal. A physical signal line (14) is connected to receive the output signal of the driver circuit (12) and to carry the output signal. A receiver circuit (16) is connected to receive the signal on the physical signal line (14) and is also connected to receive the mode select signal (SELECT). The receiver circuit (16) has a low power and full power mode selectable responsive to the mode select signal (SELECT).
    Type: Grant
    Filed: November 17, 1997
    Date of Patent: August 17, 1999
    Assignee: Texas Instruments Incorporated
    Inventor: J. Patrick Kawamura