Ring Oscillators Patents (Class 331/57)
  • Patent number: 8120435
    Abstract: A PLL circuit includes a phase detector, a loop filter (LF), a voltage-controlled oscillator (VCO), and a frequency divider. The phase detector compares a phase of a signal Fs which is input from outside with a phase of a signal Fo/N which is input from the frequency divider. The loop filter generates a signal Vin by removing alternating current components from a signal input from the phase detector. The voltage-controlled oscillator outputs a signal Fo based on the signal Vin input from the loop filter. The frequency divider converts the signal Fo output from the voltage-controlled oscillator into Fo/N (frequency division by N), and outputs it to the phase detector.
    Type: Grant
    Filed: September 20, 2010
    Date of Patent: February 21, 2012
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Jun Koyama, Takeshi Osada
  • Patent number: 8115559
    Abstract: An oscillator including a current bias circuit and a ring oscillator. The current bias circuit tracks a temperature change of the oscillator by using a control voltage and generates a plurality of bias voltages to supply a bias current according to the temperature change. The ring oscillator compares differential output signals generated according to the bias voltages and generates an oscillation signal as a result of the comparison.
    Type: Grant
    Filed: January 5, 2010
    Date of Patent: February 14, 2012
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hyoung Rae Kim, Nam Jin Song
  • Patent number: 8115560
    Abstract: In one embodiment, a circuit topology for use in an n-phase voltage controlled oscillator (VCO) or injection-locked frequency divider includes a transmission line ring having n transmission line delay segments connected at n junctions, where n is an integer greater than or equal to 3. Each transmission line segment provides a 1/n wavelength signal delay between adjacent junctions. The transmission line ring is coupled to a first power supply node. Each of the junctions has a respective transistor coupled thereto, each transistor having a first source/drain terminal coupled to its respective junction, a second source/drain terminal coupled to a second power supply node, and a gate terminal, wherein the gate terminal is coupled to a signal that is ½ wavelength out-of-phase with respect to a signal at the first source/drain terminal of the transistor.
    Type: Grant
    Filed: January 13, 2010
    Date of Patent: February 14, 2012
    Assignee: Taiwan Semiconductor Manufacturing Co., Ltd.
    Inventor: Shine Chung
  • Patent number: 8111107
    Abstract: An integrated circuit includes a charge pump having a voltage output. A voltage level detector is arranged to receive the voltage output, wherein the voltage level detector provides a first enable signal for the charge pump. A ring oscillator has multiple inverters. The ring oscillator is coupled to the charge pump. A counter control circuit is configured to provide a control signal for adjusting a frequency of the ring oscillator based on the first enable signal of the voltage level detector.
    Type: Grant
    Filed: July 7, 2010
    Date of Patent: February 7, 2012
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventor: Ming-Chieh Huang
  • Patent number: 8106716
    Abstract: One embodiment of the oscillator includes a first starved inverter and a second starved inverter. An inner inverter of the second starved inverter is cross-coupled to an inner inverter of the first starved inverter. The oscillator further includes a first inverter connected to output of the inner inverter of the first starved inverter, and a second inverter connected to output of the inner inverter of the second starved inverter.
    Type: Grant
    Filed: January 30, 2009
    Date of Patent: January 31, 2012
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Chan-kyung Kim
  • Patent number: 8093928
    Abstract: A signal source device is provided and includes a plurality of latch units, an inverter unit, and a voltage-shifting unit, which may include a capacitance unit. The plurality of latch units are substantially cascaded. The inverter unit is coupled to the latch units. The voltage-shifting unit has a first terminal coupled to the inverter unit and one of the latch units and a second terminal receiving a first input signal, for shifting a voltage level at the first terminal according to the first input signal.
    Type: Grant
    Filed: March 2, 2009
    Date of Patent: January 10, 2012
    Assignees: Mediatek Inc., National Taiwan University
    Inventors: Chih Wei Chang, Yi-Jan Chen
  • Patent number: 8095104
    Abstract: A semiconductor device includes an antenna circuit for receiving a wireless signal, a power supply circuit generating power by the wireless signal received by the antenna circuit, and a clock generation circuit to which power is supplied. The clock generation circuit includes a ring oscillator which self-oscillates and a frequency divider which adjusts frequency of an output signal of the ring oscillator in an appropriate range. A digital circuit portion is driven by a clock having high frequency accuracy, so that a malfunction such as an incorrect operation or no response is prevented.
    Type: Grant
    Filed: June 21, 2007
    Date of Patent: January 10, 2012
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Daisuke Kawae, Masami Endo, Yoshiyuki Kurokawa, Takayuki Ikeda
  • Patent number: 8089322
    Abstract: An inductance enhanced rotary traveling wave oscillator is disclosed. Portions of the transmission line conductors are increased in length and run in parallel. Because the currents in these portions travel in the same direction, the inductance of these inductors is increased. By controlling the length of the transmission line conductors in these areas compared to the lengths in which the currents travel in opposite directions, the overall impedance of the oscillator can be increased. Increased impedance leads to lower power, higher Q, and lower phase noise for the oscillator. Additionally, the folded nature of the transmission line conductors permits a longer length of transmission line conductors to be routed in a smaller area. The folded nature also permits placement of the devices to take into account their switching delays. A folded circular version of the oscillator is possible, leading to improved access to phase taps on the oscillator.
    Type: Grant
    Filed: May 14, 2009
    Date of Patent: January 3, 2012
    Inventors: Stephen M Beccue, Anh D Pham
  • Patent number: 8089321
    Abstract: Four stochastic resonators 20-1 to 20-4 outputting a pulse signal in accordance with a stochastic resonance phenomenon are unidirectionally coupled in a ring-like form to constitute a fluctuation oscillator 10. When a signal output from each of the stochastic resonators 20-1 to 20-4 is successively transmitted in the stochastic resonators 20-1 to 20-4 coupled in a ring-like form, the output timings at each stochastic resonator 20 are synchronized with each other due to a cooperation phenomenon between the stochastic resonators 20-1 to 20-4, so that each stochastic resonator 20 is self-excited to oscillate at a constant period of time.
    Type: Grant
    Filed: August 21, 2008
    Date of Patent: January 3, 2012
    Assignee: Osaka University
    Inventors: Yasushi Hotta, Teruo Kanki, Naoki Asakawa, Toshio Kawahara, Tomoji Kawai, Hitoshi Tabata
  • Patent number: 8089320
    Abstract: In one embodiment, the differential amplifier (DA) includes a first inverter inverting a first input signal and outputting the inverted first input signal to a current supply controller and a current drain controller. A second inverter inverts the first input signal and outputs the inverted first input signal as an output signal of the DA. The current supply controller supplies current to the first and second inverters in response to the inverted first input signal output from the first inverter during a first period. The current drain controller drains current from the first and second inverters in response to the inverted first input signal output from the first inverter during a second period. The output signal of the DA and the first input signal have differential phases with respect to each other and oscillate between logic high and low levels during the first period and the second period.
    Type: Grant
    Filed: January 8, 2010
    Date of Patent: January 3, 2012
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Chan-kyung Kim
  • Patent number: 8089319
    Abstract: Systems and methods for increasing the frequency range of an output signal generated by a VCO, where one or more variable delay units are incorporated into an interpolative VCO to decrease the minimum frequency at which the VCO oscillates. In one embodiment, the VCO includes a ring of serially connected inverters, a set of bypass circuits and a set of variable delay units. The bypass circuits are coupled to the ring of serially connected inverters to bypass one or more of the serially connected inverters when enabled. Each variable delay unit delays signal transitions at the input of a corresponding one of the serially connected inverters by a variable amount. The variable delay units may be positioned in series with the ring of inverters, in parallel with the bypass paths, or in parallel with corresponding inverters in the ring of inverters.
    Type: Grant
    Filed: November 24, 2009
    Date of Patent: January 3, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Masaaki Kaneko
  • Patent number: 8085098
    Abstract: A PLL circuit comprising an oscillation unit, a frequency division unit, a phase comparison unit, and a generation unit comprises a switching unit that switches between a first state in which a control voltage output from the generation unit is input into the oscillation unit and a second state in which a reference voltage is input into the oscillation unit; and a correction unit that, in the second state, compares the control voltage output from the generation unit with the reference voltage, and corrects a frequency at which the oscillation unit oscillates with respect to a voltage input into the oscillation unit, such that the control voltage output from the generation unit is equivalent to the reference voltage.
    Type: Grant
    Filed: September 15, 2009
    Date of Patent: December 27, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yoshikazu Yamazaki
  • Publication number: 20110309885
    Abstract: Disclosed herein is a delay circuit for a low power ring oscillator. The delay circuit includes: a pair of N type transistors that receive first differential input signals Vin1+ and Vin1?; a pair of P type transistors that receive second differential input signals Vin2+ and Vin2?; a differential output terminal that outputs differential output signals Vout+ and Vout? generated from the pair of N type transistors and the pair of P type transistors; an N type detector that supplies a body voltage to the pair of N type transistors; and a P type detector that supplies a body voltage to the pair of P type transistors.
    Type: Application
    Filed: September 9, 2010
    Publication date: December 22, 2011
    Applicant: SAMSUNG ELECTRO-MECHANICS CO., LTD.
    Inventors: Myeung Su KIM, Han Jin CHO, Joon Hyung LIM, Kyung Hee HONG, Yong Il KWON
  • Publication number: 20110309886
    Abstract: Oscillator circuitry is provided that is based on a ring of inverters. The ring of inverters may be single-ended or differential inverters. Digitally controlled adjustable load capacitors may be provided at inverter outputs to tune the oscillator circuitry. Each digitally controlled adjustable load capacitor may be formed from multiple varactors connected in parallel. Each varactor may have a control input that receives a digital control signal. The digitally controlled adjustable load capacitors in a given oscillator may be adjusted in unison to produce the same capacitance value for each capacitor or may be adjusted individually so that they produce different capacitance values. The inverters may include common-mode-gain reduction features such as series-connected current sources, series-connected resistors, and cross-coupled negative feedback transistors.
    Type: Application
    Filed: September 1, 2011
    Publication date: December 22, 2011
    Inventors: Mohsen Moussavi, William W. Bereza
  • Patent number: 8081037
    Abstract: An apparatus including a ring oscillator and related methods are disclosed. The ring oscillator includes at least two ring loops. A first ring loop includes a plurality of series coupled delay cells. At least one additional ring loop includes a plurality of series coupled delay cells. The at least one additional ring loop is coupled to the first ring loop by one or more common delay cells shared between the first ring loop and the at least one additional ring loops.
    Type: Grant
    Filed: June 11, 2008
    Date of Patent: December 20, 2011
    Assignee: QUALCOMM Incorporated
    Inventors: Jonghae Kim, Lew G. Chua-Eoan, Matthew Nowak
  • Patent number: 8081040
    Abstract: Aspects of the disclosure provide a voltage controlled oscillator. The voltage controlled oscillator can include a plurality of oscillation stages coupled together to generate an oscillation signal having an oscillation frequency. At least one oscillation stage of the plurality of oscillation stages can include a first portion driven by a first driving power that can be a function of a control voltage and a second portion driven by a second driving power that can be substantially independent of the control voltage. The first driving power can be provided by a first power rail in the form of a driving current that is a function of the control voltage. The second driving power can be provided by a second power rail in the form of a substantially constant voltage that is substantially independent of the control voltage.
    Type: Grant
    Filed: July 6, 2009
    Date of Patent: December 20, 2011
    Assignee: Marvell Israel (M.I.S.L) Ltd.
    Inventor: Shimon Avitan
  • Patent number: 8081038
    Abstract: Provided is a ring oscillator having an extended range of oscillation frequency by varactors coupled to delay cells even in a simple structure. The wide frequency range results from simply varying an oscillation frequency by control signals applied to the varactors. Since additional switches connected to the delay cells contribute to increase or decrease of the oscillation frequency range, the ring oscillator can conveniently be employed in various types of oscillation systems.
    Type: Grant
    Filed: July 22, 2009
    Date of Patent: December 20, 2011
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Hui Dong Lee, Kwi Dong Kim, Jong Kee Kwon
  • Patent number: 8081035
    Abstract: A multiphase oscillator with a control path for urging the rotational direction of the oscillator is disclosed. The multiphase oscillator has an electrically or magnetically or both continuous signal path over which a signal propagates subject to a phase reversal on each traversal of the signal path and active switching means that create and sustain the propagating signal. A control path has a control signal whose propagation activates each switching means in the order of the direction of propagation of the control signal on the control path so as to determine direction of the signal propagating on the signal path.
    Type: Grant
    Filed: September 27, 2007
    Date of Patent: December 20, 2011
    Assignee: Multigig Inc.
    Inventor: John Wood
  • Patent number: 8076980
    Abstract: A temperature-compensated ring oscillator includes a control signal generator and a voltage controlled oscillator. The control signal generator is configured to generate at least one control signal, and includes at least one first resistor and second resistor. A first temperature coefficient of the first resistor is negative, and a second temperature coefficient of the second resistor is positive. The voltage controlled oscillator receives the control signal, outputs an oscillation signal, and has (2k+1) cascaded inverter units, where k?1. Each of the inverter units includes a first transistor, a second transistor and an inverter. The first transistor has a drain coupled to a first supply voltage and a gate to receive the control signal. The second transistor has a source to receive a second supply voltage and a gate to receive the control signal. The inverter is coupled between the first and the second transistors.
    Type: Grant
    Filed: January 19, 2010
    Date of Patent: December 13, 2011
    Assignee: Elite Semiconductor Memory Technology Inc.
    Inventor: Yi-Heng Liu
  • Patent number: 8076957
    Abstract: The present invention is directed to reduce the chip area of a semiconductor integrated circuit. A semiconductor integrated circuit of the invention includes a first transistor, a second transistor disposed adjacent to the first transistor along a Y axis, and a third transistor disposed adjacent to the second transistor along an X axis. The semiconductor integrated circuit further includes a fourth transistor disposed adjacent to the third transistor along the Y axis and disposed adjacent to the first transistor along the X axis. The first to fourth transistors share a well, and an output signal of the first transistor and an output signal of the second transistor have phases opposite to each other. An output signal of the second transistor and an output signal of the third transistor have phases opposite to each other. An output of the third transistor and an output signal of the fourth transistor have phases opposite to each other.
    Type: Grant
    Filed: October 29, 2010
    Date of Patent: December 13, 2011
    Assignee: Renesas Electronics Corporation
    Inventor: Masanori Isoda
  • Publication number: 20110298549
    Abstract: A tunable multiphase ring oscillator includes a plurality of stages connected in series in a ring structure, where each stage generating a stage output from a stage input. Each stage of the tunable multiphase ring oscillator includes a plurality of trans-conductance cells, each generating an output from at least one portion of the stage input. Each stage further includes at least one phase shifting module for imparting at least one phase shift to the at least one portion of the stage input, an oscillator unit for generating the stage output from a combination of the plurality of outputs, and means for varying at least one of the plurality outputs so as to adjust a phase of the stage output.
    Type: Application
    Filed: June 8, 2010
    Publication date: December 8, 2011
    Applicant: The Hong Kong University of Science and Technology
    Inventors: Howard Cam Luong, Sujiang Rong
  • Patent number: 8072275
    Abstract: A digital ring oscillator outputting a toggled clock signal. The clock signal is generated by a plurality of electronic cells that are arranged in series. At least one of the plurality of electronic cells receives a feedback of the clock signal. Control signals are received at an input for the plurality of electronic cells. Each electronic cell includes a first logic gate, a second logic gate, and an inverted logic gate coupled between the first logic gate and the second logic gate. For each electronic cell, a respective control signal controls whether an output signal received from the first logic gate of a preceding electronic cell is transferred through the first logic gate to the first logic gate in a succeeding electronic cell, or is inverted and transferred through the second logic gate to the second logic gate in a preceding electronic cell, based on the control signal.
    Type: Grant
    Filed: March 25, 2010
    Date of Patent: December 6, 2011
    Assignee: Marvell International Ltd.
    Inventor: Nir Paz
  • Patent number: 8072274
    Abstract: A differential oscillation circuit according to the present invention is a differential oscillation circuit including a feedback loop circuit. The differential oscillation circuit includes: delay, circuits, cascade-connected one after another on the feedback loop circuit, each delay circuit configured to delay paired differential input signals which the delay circuit receives, and to output the delayed differential signals as paired differential output signals; and an oscillation activation detector circuit configured to detect whether the oscillation circuit is in an oscillation activation state or in a stable state, and to output a detection signal indicating a result of the detection. Furthermore, on the basis of the detection signal outputted from the oscillation activation detector circuit, each of the delay circuits controls output current values of the differential output signals. This circuit configuration enables the speeding up of the oscillation frequency of the circuit.
    Type: Grant
    Filed: December 17, 2009
    Date of Patent: December 6, 2011
    Assignee: Renesas Electronics Corporation
    Inventor: Kazunosuke Hirai
  • Patent number: 8067989
    Abstract: An alternate clock apparatus and method configured to reduce noise in selected frequency bands in an electronic device such as a communication device is described. In one embodiment the alternate clock includes a ring oscillator to generate multiple time shifted signals which may then be combined to generate clock signals at alternate frequencies to a primary reference. A resynchronization circuit may be coupled to the ring oscillator to periodically resynchronize the ring oscillator to a reference signal to reduce alternate clock jitter.
    Type: Grant
    Filed: April 13, 2009
    Date of Patent: November 29, 2011
    Assignee: Quintic Holdings
    Inventors: John B. Groe, Carrie Lo
  • Publication number: 20110279149
    Abstract: An analog-to-digital converter (ADC) suitable for measuring on-die DC or low frequency analog voltages may include a ring oscillator having a group of circuit cells successively and circularly coupled. Under certain circumstances, the ring oscillator may produce an output frequency that corresponds substantially linear to the input voltage. Other embodiments may be disclosed or claimed.
    Type: Application
    Filed: May 12, 2010
    Publication date: November 17, 2011
    Inventor: Atul Maheshwari
  • Publication number: 20110273237
    Abstract: An oscillator circuit includes a circuit loop and multiple current sources. The circuit loop includes an output having the oscillating signal. The multiple current sources are turned on independently of a phase of the oscillating signal. The current sources control magnitudes of both charging current and discharging current at nodes of the circuit loop, including the output. Relative magnitudes of different current sources determine a frequency of the oscillating signal.
    Type: Application
    Filed: May 7, 2010
    Publication date: November 10, 2011
    Applicant: Macronix International Co., Ltd.
    Inventor: Tien-Yen Wang
  • Patent number: 8054140
    Abstract: Low voltage oscillators that provide a stable output frequency with varying supply voltage are provided. The subject oscillators find use in a variety of different types of devices, e.g., medical devices, including both implantable and ex-vivo devices.
    Type: Grant
    Filed: October 17, 2007
    Date of Patent: November 8, 2011
    Assignee: Proteus Biomedical, Inc.
    Inventors: Robert Fleming, Cherie Kushner, Nilay Jani, Jonathan Withrington, Mark Zdeblick
  • Patent number: 8054139
    Abstract: A voltage-controlled oscillator is implemented with a succession of delay cells coupled in series to form an oscillator loop. The oscillator loop is supplied with reference voltages produced by a voltage generator. The reference voltages produce stable operation of the voltage-controlled oscillator. Cascode reference current generators are incorporated within the voltage generator to supply a cross-coupled arrangement of pull-up devices within each delay cell. The cross-coupled pull-up devices are instrumental in producing complementary output signaling from each delay cell. A pair of cascode current generators is configured in parallel to produce a magnitude of current according to an applied voltage and to be selectable for dual or single operation with a corresponding frequency determination.
    Type: Grant
    Filed: February 18, 2009
    Date of Patent: November 8, 2011
    Assignee: Silicon Labs Spectra, Inc.
    Inventors: Francisco Fernandez, Alexei Shkidt
  • Patent number: 8049550
    Abstract: A device that includes: (i) an evaluated circuit; (ii) a leakage current dependent oscillator configured to generate an oscillating signal that has an oscillating frequency that represents a leakage current of the evaluated circuit; (iii) a switching current dependent oscillator configured to generate an oscillating signal that has an oscillating frequency that represents a switching induced current of the evaluated circuit; (iv) a power reduction module that is configured to: (a) compare between an oscillation frequency of the leakage current dependent oscillator and an oscillation frequency of the switching current dependent oscillator, to provide a current comparison result; (b) select a power reduction technique out of a dynamic voltage and frequency scaling technique and a power gating technique in view of the current comparison result; and (c) apply the selected power reduction technique.
    Type: Grant
    Filed: September 10, 2008
    Date of Patent: November 1, 2011
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Anton Rozen, Dan Kuzmin, Michael Priel
  • Patent number: 8049570
    Abstract: An electrical/magnetic current sensing system includes a first collection mechanism configured to convert an electric field into surface charge, a second collection mechanism comprising a magnetic reactive material, and a sensor coupled to the first and second collection mechanisms. The sensor comprises an odd number, greater than or equal to three, of unidirectionally-coupled non-linear over-damped bi-stable elements. Each element comprises a resistive load, an operational transconductance amplifier (OTA) with a bipolar junction transistor differential pair, a cross-coupled OTA, and a non-linear OTA. Each element may comprise fully differential inputs and outputs. The sensor may be contained in a microchip or on a printed circuit board. A resident time difference readout device may be connected to the sensor, and may be configured to perform a power spectral density calculation. The sensor may include a resistance to voltage circuit connected between the second collection mechanism and the elements.
    Type: Grant
    Filed: March 25, 2010
    Date of Patent: November 1, 2011
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Visarath In, Patrick Longhini, Yong (Andy) An Kho, Joseph D. Neff, Antonio Palacios, Norman Liu
  • Patent number: 8044729
    Abstract: A phase locked loop (PLL) and a voltage controlled oscillator (VCO) thereof are provided. The VCO includes a ring oscillator circuit and a control circuit. The ring oscillator circuit is used for providing an output clock signal; and the control circuit is coupled to the ring oscillator circuit, and used for receiving an output voltage to respectively provide a first voltage-frequency gain and a second voltage-frequency gain so as to control a frequency of the output clock signal provided by the ring oscillator circuit, wherein the first voltage-frequency gain is larger than the second voltage-frequency gain.
    Type: Grant
    Filed: November 5, 2009
    Date of Patent: October 25, 2011
    Assignee: Phison Electronics Corp.
    Inventor: Wei-Yung Chen
  • Patent number: 8044728
    Abstract: An integrated circuit may include an inverter which may include a first transistor of a first conductivity type and a second transistor of a second conductivity type connected in parallel with the first transistor. An input of the inverter may be capable of receiving an oscillating input signal, and which may include an output of the inverter, which is connected to a capacitive device capable of being charged and discharged depending on the state of the first and second transistors being on or off. The inverter may be capable of delivering an oscillating output signal at its output. The integrated circuit may include a selector for transmitting the oscillating output signal and for masking the charging and/or discharging of the capacitive device.
    Type: Grant
    Filed: August 18, 2009
    Date of Patent: October 25, 2011
    Assignee: STMicroelectronics SA
    Inventor: Sébastien Barasinski
  • Patent number: 8044727
    Abstract: There is provided a voltage controlled ring oscillator having a plurality of ring-connected amplifiers (401), and a plurality of variable capacitance elements (502a, 502b) being respectively connected to the plurality of amplifiers and having capacitances varied by a voltage control. A plurality of load resistors (402) and a plurality of tail current sources (403) are respectively connected to the plurality of amplifiers.
    Type: Grant
    Filed: December 20, 2005
    Date of Patent: October 25, 2011
    Assignee: Fujitsu Limited
    Inventor: Hirohito Higashi
  • Patent number: 8040196
    Abstract: A digitally controlled oscillator includes a ring oscillator, a parallel resistor bank connected to a first terminal of the ring oscillator and having a resistance that varies according to a digital code, and a serial resistor bank connected to a second terminal of the ring oscillator and having a resistance that varies according to the digital code. A frequency of the ring oscillator linearly varies with a variation in the resistance of the parallel resistor bank and the resistance of the serial resistor bank according to the digital code.
    Type: Grant
    Filed: September 30, 2009
    Date of Patent: October 18, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jong-shin Shin
  • Patent number: 8040192
    Abstract: A power supply voltage output circuit includes: a power supply voltage generation unit generating a power supply voltage to be supplied into a ring oscillator; a reference clock oscillator oscillating a reference clock with respect to a clock oscillated by the ring oscillator; a phase difference detection unit detecting a phase difference between the clock from the ring oscillator and the reference clock from the reference clock oscillator; a filter unit smoothing an output of the phase difference detection unit; and a PWM signal generation unit generating a PWM signal based on an output of the filter unit such that the phase difference approaches zero.
    Type: Grant
    Filed: October 28, 2009
    Date of Patent: October 18, 2011
    Assignee: Fujitsu Limited
    Inventors: Masazumi Maeda, Yoshito Koyama
  • Patent number: 8040195
    Abstract: A current source device that cuts off an output current when stopped and obtains a desired output current upon start-up includes a first circuit having a first FET and resistors in series, a second circuit having second and third FETs in series with a point between the second and third FETs and a gate of the third FET connected, a drive circuit supplying a common drive voltage to gates of the first and second FETs, and first and second current source circuits responsive to first and second drive voltages that are gate voltages of the second and third FETs. The first and second current source circuits respectively include first and second current source FETs having the first and second drive voltages as gate voltages, and a start-up circuit changing the first and second drive voltages forcedly when the first and second current source FETs are made conductive.
    Type: Grant
    Filed: July 18, 2008
    Date of Patent: October 18, 2011
    Assignee: Oki Semiconductor Co., Ltd.
    Inventor: Nobukazu Murata
  • Patent number: 8037431
    Abstract: A design structure embodied in a machine readable medium used in a design process includes an interleaved voltage-controlled oscillator, including a ring circuit of main logic inverter gates; a plurality of delay elements connected in parallel with a selected sequence of the main logic inverter gates; wherein each delay element comprises a feedforward section, comprising controls for regulating signal transmission through feedforward elements responsive to one or more control voltages; and a proportional section for regulating signal transmission through at least one logic inverter gate; at least one temperature compensation circuit responsive to a compensating voltage input that is proportional to temperature; an electronic circuit in communication with the temperature compensation circuit and configured to provide a voltage signal responsive to temperature; an amplifier in connection with the electronic circuit to amplify the voltage signal; and a DC offset generator configured to adjust the voltage of the
    Type: Grant
    Filed: May 23, 2008
    Date of Patent: October 11, 2011
    Assignee: International Business Machines Corporation
    Inventors: David W. Boerstler, Eskinder Hailu, Jieming Qi, Mike Shen
  • Patent number: 8035453
    Abstract: An oscillator circuit includes differential variable delay circuits coupled together to form a ring oscillator. Each of the differential variable delay circuits has first and second inputs and first, second, third, and fourth transistors. A constant supply voltage is provided to sources of the first and the second transistors in each of the differential variable delay circuits. A variable supply voltage is provided to sources of the third and the fourth transistors in each of the differential variable delay circuits. Gates of the first and the third transistors are coupled to the first input. Gates of the second and the fourth transistors are coupled to the second input. The oscillator circuit generates a periodic output signal having a frequency that varies based on changes in the variable supply voltage.
    Type: Grant
    Filed: October 12, 2009
    Date of Patent: October 11, 2011
    Assignee: Altera Corporation
    Inventors: Wilson Wong, Allen Chan, Simardeep Maangat, Sergey Shumarayev
  • Patent number: 8031011
    Abstract: Oscillator circuitry is provided that is based on a ring of inverters. The ring of inverters may be single-ended or differential inverters. Digitally controlled adjustable load capacitors may be provided at inverter outputs to tune the oscillator circuitry. Each digitally controlled adjustable load capacitor may be formed from multiple varactors connected in parallel. Each varactor may have a control input that receives a digital control signal. The digitally controlled adjustable load capacitors in a given oscillator may be adjusted in unison to produce the same capacitance value for each capacitor or may be adjusted individually so that they produce different capacitance values. The inverters may include common-mode-gain reduction features such as series-connected current sources, series-connected resistors, and cross-coupled negative feedback transistors.
    Type: Grant
    Filed: June 27, 2008
    Date of Patent: October 4, 2011
    Assignee: Altera Corporation
    Inventors: Mohsen Moussavi, William W. Bereza
  • Patent number: 8031027
    Abstract: A voltage-controlled oscillator includes a voltage regulator, and a delay unit. The voltage regulator independently receives a first oscillation control signal and a second oscillation control signal to provide a regulated voltage signal which is represented by a regular ratio of combination of the first and second oscillation control signals, and the regulated voltage signal is feedback to the voltage regulator. The delay unit generates an output signal having a frequency varying in response to the regulated voltage signal.
    Type: Grant
    Filed: June 5, 2009
    Date of Patent: October 4, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jae-Hyun Park, Jong-Shin Shin
  • Patent number: 8031017
    Abstract: Described herein is the method and apparatus for determining frequency of an oscillator coupled with one or more analog devices, and for determining within-die or across-die variations in an analog property associated with the one or more analog devices, the determining based on the oscillator frequency. The analog property includes output signal swing, bandwidth, offset, gain, and delay line linearity and range. The one or more analog devices include input-output (I/O) buffer, analog amplifier, and delay line. The method further comprises updating a simulation model file based on the determining of the within-die and/or across-die variations of the analog property.
    Type: Grant
    Filed: June 26, 2009
    Date of Patent: October 4, 2011
    Assignee: Intel Corporation
    Inventors: Praveen Mosalikanti, Nasser A. Kurd, Timothy M. Wilson
  • Publication number: 20110227656
    Abstract: A semiconductor integrated circuit includes a ring oscillator and a noise canceller. The ring oscillator includes first and second signal generators. The first signal generator is configured to generate a first output signal having a first phase based on an input signal. The second signal generator is configured to generate a second output signal having a second phase different from the first phase based on the input signal. The noise canceller includes first and second amplifiers and an arithmetic module. The first amplifier is configured to amplify the first output signal generated by the first signal generator using a first amplification factor. The second amplifier is configured to amplify the second output signal generated by the second signal generator using a second amplification factor. The arithmetic module is configured to combine the first output signal amplified by the first amplifier with the second output signal amplified by the second amplifier.
    Type: Application
    Filed: September 21, 2010
    Publication date: September 22, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Yuji Satoh
  • Publication number: 20110210798
    Abstract: Some embodiments disclosed herein relate to techniques for providing a relatively constant oscillation frequency. In some instances, these techniques can make use of a ring oscillator that is powered by an adaptive voltage supply. The adaptive voltage supply provides a temperature-dependent supply voltage to respective delay elements in the ring oscillator, such that the oscillation frequency of the ring oscillator is approximately constant over a predetermined temperature range. For example, if temperature increases, the supply voltage can be increased proportionally, thereby tending to limit variation in the oscillation frequency delivered by the ring oscillator.
    Type: Application
    Filed: February 26, 2010
    Publication date: September 1, 2011
    Applicant: Infineon Technologies AG
    Inventors: Chin Yeong Koh, Kar Ming Yong
  • Patent number: 8005636
    Abstract: A method of controlling a clock signal with a print controller is provided. In response to receiving an external signal, the print controller determines the number of cycles of a clock signal generated by a ring oscillator of the print controller during a predetermined number of cycles of the external signal or the number of cycles of the external signal during a predetermined number of cycles of the clock signal and outputs the determined number of cycles to an external circuit. In response to receiving a trim value from clock trim circuitry of the print controller which trims the frequency of the clock signal based on the determined number of cycles from the external circuit, the trim value is stored in memory of the print controller. The clock trim circuitry is controlled to trim the frequency of the clock signal generated by the ring oscillator using the trim value.
    Type: Grant
    Filed: September 21, 2009
    Date of Patent: August 23, 2011
    Assignee: Silverbrook Research Pty Ltd
    Inventors: Gary Shipton, Simon Robert Walmsley
  • Patent number: 7999624
    Abstract: A source of radiation comprises a first low frequency oscillator 200 for providing a reference signal and a plurality of phase shifters 210a, 210b, 210c coupled to the first oscillator. In addition there are a plurality of phase locked loops 230a, 230b, 230c, each phase locked loop having a respective Voltage Controlled Oscillator (VCO) 240a, 240b, 240c for outputting a signal. Each phased locked loop is coupled to a respective one of the phase shifters, so that in use each VCO is phase locked to a reference signal which has been phase shifted by a respective one of the phase shifters. In this way the phase of the radiation output by each VCO may be controlled indirectly by controlling the phase shift of the reference signal. In a preferred embodiment the phase shifters are adjustable to shift the phase by an adjustable amount.
    Type: Grant
    Filed: April 24, 2007
    Date of Patent: August 16, 2011
    Assignee: City University of Hong Kong
    Inventors: Kwun Chiu Wan, Quan Xue
  • Patent number: 8000162
    Abstract: A voltage-controlled oscillator comprises a first oscillator and a second oscillator. The first oscillator may generate a plurality of intermediate clock signals at a plurality of first nodes, multiply connected to a plurality of first ring shape circuits, in response to a control voltage. The plurality of intermediate clock signals may have a different phase from each other and a same phase difference with each other. The second oscillator may generate a plurality of output clock signals at a plurality of second nodes, multiply connected to a plurality of second ring shape circuits, by changing a voltage level of the intermediate clock signals. The plurality of second ring shape circuits may pass the plurality of first nodes.
    Type: Grant
    Filed: November 9, 2009
    Date of Patent: August 16, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Chan-Kyung Kim
  • Patent number: 7990225
    Abstract: A phase-locked loop (PLL) with a decreased frequency tuning gain KVCO and a loop filter using capacitor multiplication technique to get high chip area efficiency. To get decreased frequency tuning gain, KVCO, a voltage to current converter in a voltage-controlled oscillator (VCO) in the PLL may comprise a first voltage to current converter and a second voltage to current converter. The trans-conductance of the first voltage to current converter is 1/? of that of the second voltage to current converter, wherein ?>1. The first voltage to current converter is controlled by an output voltage of a loop filter in the PLL, and the second voltage to current converter is controlled by a relative DC voltage, which may be the junction node between R1 and C1 in a loop filer of the PLL. Capacitor multiplication technique may use an auxiliary charge pump to charge or discharge the junction node between R1 and C1 inversely to the main charge pump.
    Type: Grant
    Filed: July 7, 2009
    Date of Patent: August 2, 2011
    Assignee: Marvell International Ltd.
    Inventors: Jianmin Guo, Yihui Li, Hong Xue, Yonghua Song, Tao Shui, Hao Zhou
  • Publication number: 20110175684
    Abstract: A temperature-compensated ring oscillator includes a control signal generator and a voltage controlled oscillator. The control signal generator is configured to generate at least one control signal, and includes at least one first resistor and second resistor. A first temperature coefficient of the first resistor is negative, and a second temperature coefficient of the second resistor is positive. The voltage controlled oscillator receives the control signal, outputs an oscillation signal, and has (2k+1) cascaded inverter units, where k?1. Each of the inverter units includes a first transistor, a second transistor and an inverter. The first transistor has a drain coupled to a first supply voltage and a gate to receive the control signal. The second transistor has a source to receive a second supply voltage and a gate to receive the control signal. The inverter is coupled between the first and the second transistors.
    Type: Application
    Filed: January 19, 2010
    Publication date: July 21, 2011
    Applicant: ELITE SEMICONDUCTOR MEMORY TECHNOLOGY INC.
    Inventor: Yi-Heng Liu
  • Patent number: 7982549
    Abstract: A system may include a first circuit configured to generate a first clock having a first period of oscillation, and a second circuit configured to generate a second clock having a second period of oscillation, where the difference (?T) between the first period of oscillation and the second period of oscillation remains within a specified limit even during variations in temperature and/or during variations in the supply voltage. The system may further include a control circuit, which may receive the first clock and the second clock, and adjust, according to ?T, a first target parameter corresponding to a first number of cycles of the first clock, when a current cycle count of the second clock reaches a second target parameter corresponding to a second number of cycles of the second clock.
    Type: Grant
    Filed: December 4, 2009
    Date of Patent: July 19, 2011
    Assignee: Atheros Communications, Inc.
    Inventors: Paul J. Husted, Manev Luthra, Wen-Hsing Chen
  • Patent number: 7983361
    Abstract: A clock data recovery circuit. The clock data recovery circuit comprises a transmission line, a phase locked loop, a voltage controlled oscillator, a phase selector, and a D flip-flop. The transmission line receives an input signal. The phase locked loop receives the input signal via the transmission line and a reference clock and generates a first clock signal. The voltage controlled oscillator receives the input signal via the transmission line and a control voltage from an internal node of the phase locked loop, and generates a clock signal. The phase selector receives the input signal via the transmission line and the clock signal from the voltage controlled oscillator, and generates a clock output signal. The D flip-flop receives the input signal via the transmission line and the clock output signal, and generates a data output signal.
    Type: Grant
    Filed: December 17, 2007
    Date of Patent: July 19, 2011
    Assignees: Mediatek Inc., National Taiwan University
    Inventors: Shen-Iuan Liu, Chih-Hung Lee, Lan-Chou Cho