L-c Type Oscillators Patents (Class 331/167)
  • Patent number: 7508280
    Abstract: CMOS LC tank circuits and flux linkage between inductors can be used to distribute and propagate clock signals over the surface of a VLSI chip or ?processor. The tank circuit offers an adiabatic behavior that recycles the energy between the reactive elements and minimizes losses in a conventional sense. Flux linkage can be used to orchestrate a number of seemingly individual and distributed CMOS LC tank circuits to behave as one unit. Several frequency-adjusting techniques are presented which can be used in an distributed clock network environment which includes an array of oscillators. A passive flux linkage, mechanical, and finite state machine technique of frequency adjustment of oscillators are described.
    Type: Grant
    Filed: July 19, 2005
    Date of Patent: March 24, 2009
    Assignee: LC Tank LLC
    Inventor: Thaddeus John Gabara
  • Patent number: 7504935
    Abstract: A transponder has a transponder tuned circuit, an energy store or energy supply and a starter device. The transponder tuned circuit has a tuned circuit capacitor and a tuned circuit coil with an inductive coupling to a base station for inductive energy and/or data transmission. On transmission the energy store provides a discharge current Ice. The starter device is arranged between the transponder tuned circuit and the energy store such as to generate an adjustable reference voltage Uref, which, on transmission, controls the transmission voltage Us-TSK such that an envelope curve H for the transmission voltage Us-TSK is constant over a transmission duration ts, giving a constant discharge current Ice from the energy store to supply the transponder tuned circuit and a discharge voltage Uce dependent on the reference voltage Uref for the energy store falls linearly to the reference voltage Uref at a transmission end tE.
    Type: Grant
    Filed: April 18, 2005
    Date of Patent: March 17, 2009
    Assignee: Siemens Aktiengesellschaft
    Inventors: Peter Turban, Herbert Zimmer
  • Patent number: 7501903
    Abstract: CMOS LC tank circuits and flux linkage between inductors can be used to distribute and propagate clock signals over the surface of a VLSI chip or ?processor. The tank circuit offers an adiabatic behavior that recycles the energy between the reactive elements and minimizes losses in a conventional sense. Flux linkage can be used to orchestrate a number of seemingly individual and distributed CMOS LC tank circuits to behave as one unit. Several frequency-adjusting techniques are presented which can be used in an distributed clock network environment which includes an array of oscillators. A finite state machine technique of frequency adjustment of oscillators is described. In addition, two methods of increasing the physcial layout and decreasing the power dissipation of an oscillator are described.
    Type: Grant
    Filed: February 21, 2007
    Date of Patent: March 10, 2009
    Assignee: LC Tank LLC
    Inventor: Thaddeus John Gabara
  • Patent number: 7489209
    Abstract: An oscillator for use within an implantable medical device is provided. The oscillator includes a resonator and a first switch coupled to a first resistive network. The first resistive network provides a first electrical path through the first switch and a second electrical path not going through the switch. The oscillator additionally includes a second switch coupled to a second resistive network. The second resistive network provides a third electrical path through the second switch and a fourth electrical path not going through the switch. Furthermore, the oscillator includes a transistor, the base terminal coupled with the first resistive network and the resonator and the emitter terminal coupled to the fourth resistor. The second electrical path with the first switch opened has a substantially higher resistance than the first electrical path when the first switch is closed.
    Type: Grant
    Filed: April 20, 2006
    Date of Patent: February 10, 2009
    Assignee: Transoma Medical, Inc.
    Inventor: Oleg Mosesov
  • Patent number: 7489207
    Abstract: Disclosed are design structures for systems and methods of generating a periodic signal.
    Type: Grant
    Filed: April 22, 2008
    Date of Patent: February 10, 2009
    Assignee: International Business Machines Corporation
    Inventor: Ram Kelkar
  • Patent number: 7479839
    Abstract: A method and apparatus for varactor bank switching for a voltage controlled oscillator is disclosed. Varactor bank switching involves generating a negative bias voltage signal as a control signal for a varactor bank switch in an off-state, the varactor bank switch comprising a pass-gate circuit including switching transistors. Generating the negative bias voltage signal includes employing an active rectifier circuit running at the speed of an oscillation signal, the negative bias voltage signal maintaining the gate-source voltage of the pass-gate circuit below a threshold voltage to prevent said switching transistors from becoming conductive in an off-state.
    Type: Grant
    Filed: March 31, 2008
    Date of Patent: January 20, 2009
    Assignee: International Business Machines Corporation
    Inventors: Marcel A. Kossel, Thomas E. Morf, Jonas R. Weiss
  • Publication number: 20090009257
    Abstract: Implementations are presented herein that relate to circuit arrangements that employ the use of a varactor.
    Type: Application
    Filed: July 6, 2007
    Publication date: January 8, 2009
    Applicant: Infineon Technologies AG
    Inventors: Anders Emericks, Lars Karlsson
  • Patent number: 7474164
    Abstract: A radar oscillator has an oscillation unit and first and second switch circuits. The first switch circuit turns off an electric power supply to an amplifier in a non-input period of a pulse signal to set the oscillation unit in a non-oscillation state and turns on the electric power supply to the amplifier in an input period of the pulse signal to set the oscillation unit in an oscillation state. The second switch circuit turns on an electric power supply to an LC resonator in a period immediately before the pulse signal is input in a period in which the pulse signal is not input to supply a current to the LC resonator and turns off the electric power supply to the LC resonator at a timing at which the pulse signal is input, so that activation of an oscillation operation of the oscillation unit is accelerated.
    Type: Grant
    Filed: January 27, 2006
    Date of Patent: January 6, 2009
    Assignees: Anritas Corporation, Matsushita Electric Industrial Co. Ltd.
    Inventors: Sumio Saito, Masanori Ejima, Yutaka Arayashiki
  • Patent number: 7474166
    Abstract: A PLL frequency synthesizer circuit includes a voltage-controlled oscillator circuit provided with a capacitor, an inductor, and a variable capacitor element oscillating using the resonance frequencies of the capacitor and inductor, for outputting the oscillation frequency signal of a variable capacitor element, a negative feedback loop circuit capable of looping the signal output from the voltagecontrolled oscillator circuit and performing a frequency acquisition operation for adjusting the frequency of the signal to a desired locking frequency, a tuning circuit for performing tuning so that the oscillation frequency approaches the locking frequency, by modulating the capacitance value of the capacitor of the voltage-controlled oscillator circuit prior to the frequency acquisition operation, and a reference potential application circuit for applying a reference potential to the variable capacitor element of the voltage-controlled oscillator circuit during the tuning operation performed by the tuning circuit.
    Type: Grant
    Filed: March 31, 2005
    Date of Patent: January 6, 2009
    Assignee: NEC Electronics Corporation
    Inventor: Toshiyuki Tanaka
  • Publication number: 20090002085
    Abstract: 4Less-Xtaless, Capless, Indless, Dioless TSOC Design of SOC or 4Free-Xtafree, Capfree, Indfree, Diofree TSOC Design of SOC is the True System On Chip Design of Security Of Community. Xtaless is Xtaless Clock Generator generating the reference clock having the superior quality of crystal clock without the on-board external crystal. Capless has the Capless Toggle and Capless LDVR. Capless Toggle is the de-bouncing circuit without the external on-board capacitor. Capless LDVR is the Low Drop Voltage Regulator having no external on-board capacitor. Indless is the Indless SM of Switch Mode Power Supply having no external on-board inductor. The Indless SM adopts the PHM of Pulse Hybrid Modulation of the PWM and PFM and making smooth load adaptive hybrid operations. Both LDVR and SM have the hybrid of the hybrid mode of digital and analog modes. Furthermore, with circuit configuration, the LDVR and SM can share the same driver.
    Type: Application
    Filed: March 25, 2008
    Publication date: January 1, 2009
    Inventors: Min Ming Tarng, Mei Jech Lin, Eric Yu-Shiao Tarng, Alfred Yu-Chi Tarng, Angela Yu-Shiu Tarng, Jwu-Ing Nieh, Huang-Chang Tarng, Shun-Yu Nieh
  • Patent number: 7471164
    Abstract: An oscillator is provided having an oscillator circuit including at least one oscillator circuit inductor and a first oscillator circuit capacitor, whereby the value of the first oscillator circuit capacitor is reversible by means of the first control voltages between different stages. The oscillator is characterized by a first control voltage source, which applies first control voltages with at least three stepwise different values to the first oscillator circuit capacitor. Preferably, the control voltages are generated over a network of current sources and resistors, whereby the network compensates for the thermal response of the oscillator. Further, a method for operating this type of oscillator is presented.
    Type: Grant
    Filed: April 21, 2005
    Date of Patent: December 30, 2008
    Assignee: Atmel Germany GmbH
    Inventor: Reinhard Reimann
  • Publication number: 20080315966
    Abstract: An oscillation circuit induces a first inverter, a second inverter, a first inductive load, a second inductive load and a capacitive load. A first inverter and a second inverter receive a first signal and a second signal, and invert the first and the second signal to output a first inverted signal and a second inverted signal respectively. An output end of the first inverter is electrically connected to a first inductive load, and an output end of the second inverter is electrically connected to a second inductive load. Further, a capacitive load is electrically connected to the output end of the first inverter and the output end of the second inverter, so as to receive the first and the second inverted signal respectively. The capacitance of the capacitive load changes with a control signal.
    Type: Application
    Filed: August 18, 2008
    Publication date: December 25, 2008
    Applicant: INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE
    Inventors: Hung-Wen Lu, Chau-Chin Su
  • Patent number: 7463106
    Abstract: Disclosed is a push-push voltage controlled oscillator which obtains output signals having a frequency two times the fundamental resonance frequency of an LC resonator with differential signals having the same amplitude and opposite phases, creating the advantage of high frequency differential outputs which are obtained using such a voltage controlled oscillator, and thus reducing current consumption.
    Type: Grant
    Filed: April 14, 2006
    Date of Patent: December 9, 2008
    Assignee: Industry-Academic Cooperation Foundation - Yonsei University
    Inventors: Hyun-Chol Shin, Hyun Kim
  • Patent number: 7463107
    Abstract: The invention is directed to a resonant circuit having a frequency-determining element which has at least one switchable frequency-changing element connected in parallel therewith. The frequency-changing element has two series-connected transistors whose control connections are connected to a node that receives a fixed potential. First connections of the two series-connected transistors are connected to one another and also to a control input for a control signal for switching the frequency-changing element of the resonant circuit. The invention keeps the control voltage for the two transistors at a higher potential than the threshold voltage for the transistors. This reduces a parasitic capacitance in the two transistors during operation.
    Type: Grant
    Filed: September 6, 2006
    Date of Patent: December 9, 2008
    Assignee: Infineon Technologies AG
    Inventor: Tindaro Pittorino
  • Patent number: 7449971
    Abstract: Provided is a transistor oscillating circuit capable of reducing change in oscillating frequency due to change in power supply voltage by improving a base bias circuit of an oscillating transistor 3. In a transistor oscillating circuit, an oscillating circuit 3 of which an emitter is connected to ground through an emitter load resistor 8, a resonance circuit 2 is connected between a base and the ground, and a collector is connected to a power supply terminal, is included, base bias resistors 9 and 10 are connected between the base and the collector and between the base and the emitter of the oscillating transistor 3, and a capacitor 7 is connected between the emitter of the oscillating transistor 3 and AC-ground.
    Type: Grant
    Filed: June 7, 2006
    Date of Patent: November 11, 2008
    Assignee: ALPS Electric Co., Ltd.
    Inventors: Hiroki Kobayashi, Masaki Tagai, Ryutaro Makita, Toru Kozu
  • Patent number: 7449970
    Abstract: A frequency fine tuning circuit for use in a voltage-controlled oscillator is provided. The frequency tuning circuit includes a first varactor, a second varactor and a center bias unit. The second varactor is coupled to the first varactor at a first node. The center bias unit maintains a node voltage of the first node at a constant bias voltage level.
    Type: Grant
    Filed: May 2, 2006
    Date of Patent: November 11, 2008
    Assignee: Samsung Electronics, Co., Ltd.
    Inventors: Jin-Hyuck Yu, Je-Kwang Cho
  • Patent number: 7432768
    Abstract: Provided are a voltage controlled digital analog oscillator and a frequency synthesizer using the same, the oscillator comprising an oscillator having a frequency of an output signal being determined by a voltage inputted to an analog input end and a digital value inputted to a digital input end; and a digital tuner for comparing the voltage inputted to the analog input end to first and second threshold voltages and changing the digital value inputted to the digital input end according to the result, whereby it is possible to obtain a broadband frequency output with less noise.
    Type: Grant
    Filed: June 22, 2004
    Date of Patent: October 7, 2008
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Seon Ho Han, Jin Ho Han, Mun Yang Park
  • Patent number: 7426373
    Abstract: An impedance tuning system, especially for a cellular telephone system. The system can be used to match the impedance of an antenna element with that of an output stage of a transmitter driving the antenna element. The system includes a piezo capacitor in parallel with the magnetostrictive inductor to form an LC circuit. A voltage controller applies a voltage bias signal to the piezo capacitor and a current controller applies a current bias signal to the inductor. A primary controller monitors the frequency of the output signal from the transmitter and controls the voltage and current controllers as needed to alter the impedance of the system as needed to match the impedance of the antenna element with that of the output stage of the transmitter. In an alternative form an ultrasonic sensor is provided.
    Type: Grant
    Filed: January 11, 2005
    Date of Patent: September 16, 2008
    Assignee: The Boeing Company
    Inventors: Dan J Clingman, Frederick T. Calkins
  • Patent number: 7423495
    Abstract: An oscillator includes a first resonator circuit, a second resonator circuit coupled to the first resonator circuit and a reconfigurable network having a transconductance and coupled to at least one of the resonator circuits. Reconfiguration of the reconfigurable network with respect to the transconductance allows selection of one of multiple oscillation modes of the oscillator.
    Type: Grant
    Filed: June 26, 2006
    Date of Patent: September 9, 2008
    Assignee: Infineon Technologies AG
    Inventors: Andrea Bevilacqua, Federico Pietro Pavan, Christoph Sandner
  • Patent number: 7414488
    Abstract: A differential voltage controlled oscillator (VCO) employed in a frequency synthesizer used as a local oscillator of a wireless communication on-chip transmitter/receiver is provided. More particularly, a differential current negative feedback VCO equipped with a current-current negative feedback circuit that suppresses low- and high-frequency noise is provided. A differential current negative feedback VCO includes a resonator determining oscillation frequency, and an oscillator generating negative resistance. In the oscillator of the differential current negative feedback VCO, transistors Q1 and Q2 form a cross-coupled pair, and negative resistance is generated by positive feedback of the cross-coupled pair. And, transistors Q1 and Q3 together with an emitter resistor and a capacitor form a current negative feedback part, and transistors Q2 and Q4 together with an emitter resistor and a capacitor form another current negative feedback part which is disposed opposite to a resonator.
    Type: Grant
    Filed: September 11, 2006
    Date of Patent: August 19, 2008
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Ja Yol Lee, Sang Heung Lee
  • Patent number: 7411468
    Abstract: There is a disclosed an oscillator for generating a periodic signal, comprising a transistor and two electro-magnetically coupled inductors in positive feedback configuration, one of the inductors is connected to the drain or gate of the transistor, and the other being connected to the source to maintain the same phase of the two voltages at the two nodes. Two or more of such single ended oscillators can be connected together to form a differential oscillator, and the invention can be generalized by the use of any active device and not just transistors.
    Type: Grant
    Filed: August 29, 2003
    Date of Patent: August 12, 2008
    Assignee: Hong Kong University of Science and Technology
    Inventors: Howard Cam Luong, Ka-Chun Kwok
  • Patent number: 7408422
    Abstract: An electronic circuit element has two capacitance values selected by means of a main control signal. The electronic circuit element comprises two variable-capacitance electronic components connected in parallel and each receiving opposite intermediate control signals, derived from the main control signal. The two variable-capacitance components are differentiated by a configuration parameter. The electronic circuit element exhibits a variation in capacitance corresponding to a difference between respective variations in capacitance of the two variable-capacitance electronic components during an inversion of the main control signal. The variation in capacitance of the electronic circuit element may be less than 5 attoFarads.
    Type: Grant
    Filed: August 16, 2006
    Date of Patent: August 5, 2008
    Assignee: STMicroelectronics S.A.
    Inventors: Sebastien Dedieu, Jean-Francois Larchanche, Frederic Paillardet
  • Patent number: 7405632
    Abstract: A voltage-controlled oscillator includes (i) a first variable-capacity element, (ii) a resonance circuit whose resonance frequency changes in accordance with a control voltage applied to the first variable-capacity element, (iii) a second variable-capacity element connected in parallel with the first variable-capacity element, (iv) resonance frequency range switching means which switches the variation range of the resonance frequency of the resonance circuit by switching the capacity of the second variable-capacity element, and (v) a resonance frequency correction circuit which corrects the resonance frequency in such a manner as to prevent the ratio between resonance frequencies before and after the switching of the variation range from depending on the control voltage.
    Type: Grant
    Filed: October 31, 2006
    Date of Patent: July 29, 2008
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Yusuke Kishino
  • Publication number: 20080174378
    Abstract: An L-C resonant circuit with an adjustable resonance frequency, having a capacitor and a first inductor electrically coupled together and a second inductor magnetically coupled to the first inductor. Additionally, there is a control circuit to sense a signal representing a first current flowing through the first inductor and to force through the second inductor a second current that is a replica of the first current for setting the adjustable resonance frequency of the L-C resonant circuit.
    Type: Application
    Filed: January 16, 2008
    Publication date: July 24, 2008
    Applicant: STMicroelectronics S.r.l.
    Inventors: Giuseppe Cusmai, Matteo Repossi, Guido Albasini, Francesco Svelto
  • Patent number: 7400209
    Abstract: Present invention relates to an oscillator circuit comprising: resonator means (102) and, first and second emitter followers (116, 118) being symmetrically coupled to the resonator means and been connected to further emitter followers (120, 122) for providing capacitive loading.
    Type: Grant
    Filed: February 10, 2004
    Date of Patent: July 15, 2008
    Assignee: NXP B.V.
    Inventors: Hugo Veenstra, Edwin Van Der Heijden, Wei Liat Chan
  • Patent number: 7391272
    Abstract: A voltage controlled oscillator includes a resonant circuit, a trimming capacitor and a full adder. The resonant circuit includes a negative resistor, an inductor and an oscillation frequency setting capacitor having a variable capacitance according to a controlled voltage based on a oscillation frequency data. The trimming capacitor is connected in parallel to the oscillation frequency setting capacitor. The trimming capacitor has capacitors each of which has a variable capacitance according to an input signal thereof. The full adder is connected to the trimming capacitor. The full adder generates the input signal based on frequency information and an automatic proofreading value received thereto.
    Type: Grant
    Filed: November 23, 2005
    Date of Patent: June 24, 2008
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Ken Fujita, Yuko Murase
  • Publication number: 20080143453
    Abstract: An oscillator circuit that generates an oscillation signal is provided. The oscillator circuit includes: a voltage controlled oscillator that outputs the oscillation signal with a frequency corresponding to a provided control voltage; and a jitter demodulator that extracts a phase fluctuation component of the oscillation signal outputted by the voltage controlled oscillator and modulates the control voltage according to the phase fluctuation component. The oscillator circuit may further include a low pass filter that removes a frequency component larger than a predetermined cutoff frequency of the control frequency inputted to the voltage controlled oscillator and provides the same to the voltage controlled oscillator.
    Type: Application
    Filed: December 13, 2006
    Publication date: June 19, 2008
    Inventors: Kiyotaka Ichiyama, Masahiro Ishida
  • Patent number: 7388446
    Abstract: A variable capacitor modulator for use in a voltage controlled oscillator, includes a differential varactor block, coupling capacitors for connecting nodes of the varactor block to a tank circuit, and an element connected between the respective nodes and ground to trim the gain of the variable capacitor modulator.
    Type: Grant
    Filed: February 10, 2005
    Date of Patent: June 17, 2008
    Assignee: Zarlink Semiconductor Ab
    Inventors: Viatcheslav Igorevich Souetinov, Alexander Alekseevich Krasin, Alexander Victorovich Koulakov
  • Patent number: 7385452
    Abstract: A VCO is based on a capacitively emitter degenerated topology which uses a cross-coupled MOS pair as the degeneration cell. The cross-coupled MOS pair contributes additional conductance and results in a higher maximum attainable oscillation frequency and better negative resistance characteristics as compared to the other topologies at high frequencies. These properties of the disclosed VCO combined with small effective capacitance enable low-power low-noise high-frequency VCO implementations.
    Type: Grant
    Filed: February 7, 2006
    Date of Patent: June 10, 2008
    Assignee: Regents of the University of Minnesota
    Inventors: Ramesh Harjani, Byung-Hoo Jung
  • Publication number: 20080129398
    Abstract: This disclosure describes designs for a digitally controlled oscillator (DCO). The DCO can overcome many of the shortcomings associated with conventional voltage controlled oscillators (VCOs), and may improve wireless communication devices. The described DCO may improve the frequency synthesis process, reduce noise in a wireless communication device, and allow for simplification of various components of the device.
    Type: Application
    Filed: November 30, 2006
    Publication date: June 5, 2008
    Inventors: Bo Sun, Arun Jayaraman, Gary John Ballantyne, Gurkanwal S. Sahota
  • Patent number: 7375598
    Abstract: System and method for increasing the frequency tuning range of a RF/microwave LC oscillator. A preferred embodiment comprises a voltage controlled oscillator (VCO) configured to generate an output signal at a frequency that is dependent upon a magnitude of an input voltage level and an effective inductance of an inductive load and a variable inductor coupled to the VCO. The variable inductor comprises a primary inductor coupled to the VCO to produce a magnetic field based upon a current flowing through the primary inductor and a secondary inductor magnetically coupled to the primary inductor, the secondary inductor to affect the magnitude of the effective inductance of the primary inductor.
    Type: Grant
    Filed: December 10, 2004
    Date of Patent: May 20, 2008
    Assignee: Texas Instruments Incorporated
    Inventors: Chih-Ming Hung, Dirk Leipold, Nathen Barton
  • Publication number: 20080111643
    Abstract: The compensation circuit comprises an oscillator, a first variable delay line, a second variable delay line, a phase detector and a controller. The oscillator generates an oscillation signal to input into a first transmission line and a second transmission line. The first variable delay line receives the oscillation signal transmitted through the first transmission line. The second variable delay line receives the oscillation signal transmitted through the second transmission line. The phase detector compares the phases of the two oscillation signals from the variable delay lines to generate a phase difference signal. The controller adjusts the variable delay lines to compensate for asynchronous signal transmission of the transmission lines according to the phase difference signal.
    Type: Application
    Filed: October 27, 2006
    Publication date: May 15, 2008
    Applicant: ATEN INTERNATIONAL CO., LTD.
    Inventor: Fu-Chin Shen
  • Publication number: 20080111644
    Abstract: A voltage control oscillator (VCO) includes a VCO circuit and a back-gate coupling circuit, wherein the VCO circuit includes at least a first transistor, a second transistor and a resonant cavity formed by an inductor and a capacitor. The back-gate coupling circuit is formed by a plurality of capacitors and a plurality of resistors. In the embodiments of the present invention, the capacitors are coupled to the back-gate terminals of the first transistor and the second transistor, so as to reduce the power consumption and the phase noise of the VCO.
    Type: Application
    Filed: February 5, 2007
    Publication date: May 15, 2008
    Applicant: National Taiwan University of Science and Technoloy
    Inventors: Sheng-Lyang Jang, Shao-Hua Lee, Yun-Hsueh Chuang, Chung-Ching Chiu
  • Patent number: 7372343
    Abstract: The invention is directed to an oscillator circuit in which a frequency-determining resonant circuit includes an inductive element, a first capacitive element and at least one second capacitive element which is connected in series with the first capacitive element. A node is provided between the first capacitive element and at least one second capacitive element. The oscillator circuit contains a damping reduction amplifier which is arranged in parallel with the frequency-determining resonant circuit. In addition, the oscillator circuit has a first tuneable capacitive element, which is connected in parallel with the first capacitive element of the resonant circuit and has a connection connected to the node.
    Type: Grant
    Filed: January 20, 2006
    Date of Patent: May 13, 2008
    Assignee: Infineon Technologies AG
    Inventor: Tindaro Pittorino
  • Patent number: 7369007
    Abstract: An oscillating circuit includes an oscillating transistor in which the collector or the base is grounded in a high-frequency manner, and a bias resistor connects the emitter of the oscillating transistor to a ground in a direct-current manner. In the oscillating circuit, a resonance unit, having maximum impedance at the oscillation frequency, is interposed between the bias resistor and the ground. Thus, an oscillation signal is obtained from the connection point between the bias resistor and the resonance unit.
    Type: Grant
    Filed: March 14, 2006
    Date of Patent: May 6, 2008
    Assignee: Alps Electric Co., Ltd
    Inventor: Hiroki Kobayashi
  • Patent number: 7362194
    Abstract: An oscillator circuit is formed of a differential LC resonant circuit formed of an L load differential circuit including inductance-variable portions and a capacitor element, and a positive feedback circuit formed of N-channel MOS transistors. The inductance-variable portion is configured to vary the inductance by selecting a plurality of switch circuits arranged between a plurality of arbitrary positions on a spiral interconnection layer and the input/output terminal, and thereby can control an oscillation frequency. The inductance-variable portions form an inductor pair when the switch circuit among the switch circuits coupled between the first input/output terminals is turned on together with the switch circuit.
    Type: Grant
    Filed: February 20, 2007
    Date of Patent: April 22, 2008
    Assignee: Renesas Technology Corp.
    Inventors: Hiroshi Komurasaki, Tomohiro Sano, Hisayasu Sato, Toshio Kumamoto, Yasushi Hashizume
  • Publication number: 20080079508
    Abstract: Provided is an Inductor-Capacitor (LC) quadrature Voltage Controlled Oscillator (VCO) having a startup circuit which can accurately select one of +90° and ?90° as a phase difference between two clocks generated by the LC quadrature VCO by embodying the startup circuit therein by using a phase detector and a controller.
    Type: Application
    Filed: December 22, 2006
    Publication date: April 3, 2008
    Inventors: Sang-Jin Byun, Cheon-Soo Kim
  • Patent number: 7352256
    Abstract: A crystal oscillation circuit can correctly suppress the resonance of a B mode, thereby correctly excite the resonance of a C mode. Since the crystal oscillation circuit uses a quartz oscillator of an SC cut or an IC cut, the B mode (unnecessary mode) frequency is close to the C mode (main mode) frequency. Therefore, a C mode resonance circuit (main mode resonance circuit) for passing a C mode frequency and a trap circuit for suppressing the oscillation at an unnecessary mode frequency are provided in the feedback loop of the crystal oscillation circuit.
    Type: Grant
    Filed: June 6, 2006
    Date of Patent: April 1, 2008
    Assignee: Nihon Dempa Kogya Co., Ltd.
    Inventor: Takeo Oita
  • Publication number: 20080068108
    Abstract: A method for detecting capacitor variation in a device comprises operating an oscillator in the device, the oscillator being an Inductive-Capacitive (LC) oscillator and including an inductor of known value and a capacitor under test, comparing an output of the oscillator to a reference output, and evaluating variation for a plurality of capacitors in the device based on the comparing.
    Type: Application
    Filed: August 31, 2006
    Publication date: March 20, 2008
    Applicant: Microtune (Texas), L.P.
    Inventors: Jan-Michael Stevenson, Timothy M. Magnusen
  • Patent number: 7345554
    Abstract: A phase-locked loop that can be integrated into a semiconductor product comprises: a phase comparator having a first input, a second input and an output, said first input receiving a reference frequency; a low-pass filter having an input connected to said output of said phase comparator and having an output generating an electric control signal (Vtune); an oscillating circuit generating a predefined frequency signal to be controlled; a dividing block having an input receiving the oscillating signal and an output connected to said second input of said phase comparator. The oscillating circuit comprises a BAW-type acoustic resonator having first and second resonant frequencies and associated with a first inductive partner element to cancel out said second resonant frequency and with a second capacitive partner element for regulating said first resonant frequency, said at least first resonator component being adjusted via said electric signal (Vtune).
    Type: Grant
    Filed: December 29, 2004
    Date of Patent: March 18, 2008
    Assignee: STMicroelectronics S.A.
    Inventors: Andreia Cathelin, Didier Belot
  • Patent number: 7342464
    Abstract: The functionality and performance of a voltage-controlled oscillator are improved by enabling continuously adjusting an inductor by a control signal. The oscillator has a variable inductor unit with variable inductance; a variable capacitance device connected to the variable inductor unit; an output unit that oscillates at an oscillation frequency determined by the inductance of the variable inductor unit and the capacitance of the variable capacitance device; and a control signal generator for modulating the oscillation frequency. The variable inductor unit has a first inductor; a current signal generator for detecting an electric signal denoting current flowing to the first inductor, and generating a current signal based on the electric signal; and a second inductor that receives the current signal. The first inductor and second inductor are disposed to a predetermined magnetically coupled position, and the variable inductor unit sets the inductance of the first inductor desirably.
    Type: Grant
    Filed: May 10, 2006
    Date of Patent: March 11, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Takuo Hino
  • Publication number: 20080042766
    Abstract: A Design For Yield (DFY) of Crystal Chip (XtalChip) is to have the high yield of high quality high accurate clock chip to be able to integrated in the SOC environment to save the production cost and board space, etc. The LC oscillation (LCO) tank has the constant oscillation amplitude control, constant oscillation common mode voltage, and inductor parametric resistance compensation over temperature and oscillation glitch filter capacitors.
    Type: Application
    Filed: November 6, 2006
    Publication date: February 21, 2008
    Inventors: Min Ming Tarng, Minh V. Nguyen, Eric Yu-Shiao Tarng
  • Publication number: 20080042765
    Abstract: A XtalClkChip based on the application of hierarchical circuit and noise circuit design on the RF circuits of LC oscillation tank and the multi-phase fractional PLL are developed. The XtalClkChip combines both the XtalChip and multi-phase fractional PLL to provide the customer's clock to customer directly. This XtalChip will replace the crystal and the crystal circuit. The XtalClkChip will replace all the customer's clock circuit.
    Type: Application
    Filed: August 5, 2006
    Publication date: February 21, 2008
    Inventors: Min Ming Tarng, Minh V. Nguyen, Eric Yu-Shiao Tarng
  • Patent number: 7330083
    Abstract: An oscillator includes a resonance circuit, and a feedback circuit coupled to the resonance circuit. The resonance circuit includes a main resonance element circuit, and a voltage dividing circuit that divides an output voltage of the main resonance element circuit and applies a divided voltage to the feedback circuit.
    Type: Grant
    Filed: December 6, 2005
    Date of Patent: February 12, 2008
    Assignee: Fujitsu Media Devices Limited
    Inventors: Nobuaki Matsuo, Alejandro Puel
  • Patent number: 7330082
    Abstract: An nth-order oscillator system for providing a resonating signal, a method of generating a resonating signal and a communications system. In one embodiment, the nth-order oscillator system, n being greater than two, includes (1) an amplifier configured to provide an intermediate signal and (2) a feedback loop including an nth-order complex LC tank and configured to generate the resonating signal by feeding back a complex-filtered form of the intermediate signal to the amplifier.
    Type: Grant
    Filed: August 23, 2004
    Date of Patent: February 12, 2008
    Assignee: Texas Instruments Incorporated
    Inventors: Chih-Ming Hung, Robert B. Staszewski, Dirk Leipol
  • Patent number: 7327201
    Abstract: A semiconductor integrated circuit device having a voltage controlled oscillation circuit that is capable of sufficient oscillation performance and a wireless communication device having the semiconductor integrated circuit device are disclosed. A difference between the maximum value and the minimum value of the oscillation output signal is automatically controlled to be substantially equal to the first predetermined voltage which is the threshold voltage of the oscillation MOSFET for sufficient phase noise performance. It is further disclosed that the difference between the maximum value and the minimum value of the oscillation output signal may be varied by the change of the threshold voltage of the MOSFET caused by substrate bias effect, while maintaining the sufficient phase noise performance.
    Type: Grant
    Filed: December 15, 2005
    Date of Patent: February 5, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Daisuke Miyashita, Hiroki Ishikuro
  • Patent number: 7323947
    Abstract: An oscillator circuit includes first and second transistors forming a differential pair, an output combiner connected to first terminal sides of the first and second transistors, and a current source connected to second terminal sides of the first and second transistors.
    Type: Grant
    Filed: December 29, 2004
    Date of Patent: January 29, 2008
    Assignee: Fujitsu Limited
    Inventor: Hisao Shigematsu
  • Publication number: 20080012654
    Abstract: Provided are a linearized variable-capacitance module for a voltage-controlled oscillator (VCO) and an LC resonance circuit using the same. The VCO is a circuit for outputting a certain frequency in response to an input control signal (voltage or current). The VCO includes an inductor, a variable capacitor (or a varactor), and an active device for compensating for loss of energy caused by the inductor and varactor. The frequency of the VCO is varied by changing inductance or capacitance. In general, the VCO includes a variable-capacitance device (i.e., the varactor) so that the frequency of the VCO may be varies by changing the capacitance via a control voltage. In most cases, the frequency of the VCO varies nonlinearly with respect to the control voltage. The nonlinear variation in the frequency of the VCO results in a great variation in a VCO gain within a certain control voltage range.
    Type: Application
    Filed: June 26, 2007
    Publication date: January 17, 2008
    Inventors: Seon Ho HAN, Cheon Soo KIM
  • Publication number: 20080007361
    Abstract: An oscillator, comprising an LC tank circuit and a negative resistance circuit. The negative resistance circuit is coupled to the LC tank circuit and comprises a pair of transistors and a pair of voltage drop generators. The transistors have first terminals and second terminals, wherein the first terminals are cross-coupled to the second terminals thereof. The voltage drop generators are respectively coupled between the first and second terminals of the transistors.
    Type: Application
    Filed: January 29, 2007
    Publication date: January 10, 2008
    Applicant: MEDIATEK INC.
    Inventor: Chia-Huang Fu
  • Patent number: 7317363
    Abstract: There is provided a phase locked loop circuit which receives a reference signal having a reference frequency and a first signal having a first frequency, compares phases of the reference signal and first signal, applies a control voltage based on a phase comparison result to an input terminal of a voltage controlled oscillator to generate a second signal having an oscillation frequency and output the second signal from an output terminal, and supplies the second signal to a divider to divide the frequency of the second signal and output the first signal; and a controller which generates and supplies a control signal to the voltage controlled oscillator, wherein the voltage controlled oscillator has an arrangement in which a coil and variable capacitance are connected in parallel between the input terminal and output terminal, and one of a plurality of capacitances is selectively connected between the input terminal and output terminal by a switch in parallel with the variable capacitance, and ON/OFF of the sw
    Type: Grant
    Filed: December 16, 2005
    Date of Patent: January 8, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shouhei Kousai, Hiroyuki Kobayashi