Amplitude Stabilization And Control Patents (Class 331/109)
  • Patent number: 8035455
    Abstract: An amplitude control circuit (100) can include a peak level detect circuit (102) that generates a peak voltage signal (Vpeak?) based on a peak level of signal Xosc. An amplitude bias control circuit (104) can generate a bias voltage Vbc that can correspond to a peak amplitude of a received oscillator signal Xosc, and can change according to variations in a transistor threshold voltage due to process, operating conditions and voltage.
    Type: Grant
    Filed: September 29, 2006
    Date of Patent: October 11, 2011
    Assignee: Cypress Semiconductor Corporation
    Inventor: Michael McMenamy
  • Publication number: 20110187468
    Abstract: A low headroom oscillator operates at low supply voltages without the use of monostable circuits or flip flops. The oscillator operates in multiple states which allow for the charging and discharging of the capacitors alternately to enable the proper operating of the oscillator at low supply voltages without locking up.
    Type: Application
    Filed: February 2, 2010
    Publication date: August 4, 2011
    Inventor: Gareth FINN
  • Patent number: 7982553
    Abstract: This invention discloses a clock generator capable of automatically adjusting output clock when process, voltage, or temperature variation occurred. The clock generator comprises a current generator, for generating a first current and a second current according to a control voltage; a oscillator, coupled to the current generator, for generating a clock signal according to the first current; and a voltage adjuster, coupled to the current generator and the oscillator, for adjusting the control voltage according to the clock signal and the second current; wherein, when the signal frequency of the clock signal changed, the voltage adjuster correspondingly adjusts the control voltage so as to adjust the first current.
    Type: Grant
    Filed: May 14, 2009
    Date of Patent: July 19, 2011
    Assignee: Realtek Semiconductor Corp.
    Inventors: Chen-Chih Huang, Tsung Yen Tsai
  • Publication number: 20110121907
    Abstract: A driver device that forms an oscillation loop with a vibrator and causes the vibrator to produce driving vibrations includes a current-voltage converter that converts a current that flows through the vibrator into a voltage, an output circuit that causes the vibrator to produce the driving vibrations based on a signal that is converted into a voltage with respect to a given voltage, and a high-pass filter that is provided in the oscillation loop between the current-voltage converter and the output circuit. The driver device causes the vibrator to produce the driving vibrations while changing a reference potential of the high-pass filter, and then causes the vibrator to produce the driving vibrations while fixing the reference potential.
    Type: Application
    Filed: November 26, 2007
    Publication date: May 26, 2011
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Masahiro Kanai, Naoki Yoshida, Eitaro Otsuka
  • Publication number: 20110095833
    Abstract: A method for generating an oscillator signal uses a multiphase oscillator having a plurality of input stages and a reference stage. Each input stage produces an input stage voltage that represents a phase for the oscillator. The input stage voltages produced by each of the input stages are compared to a reference voltage produced by the reference stage. An input stage having a maximum input stage voltage is selected and an output of the selected input stage having the maximum input stage voltage is changed. A current need of the oscillator is detected with a negative feedback loop coupled to the reference stage. An appropriate supply current is provided to each input stage with the negative feedback loop.
    Type: Application
    Filed: December 29, 2010
    Publication date: April 28, 2011
    Applicant: Alpha and Omega Semiconductor Incorporated
    Inventors: Behzad Mohtashemi, Allen Chang
  • Patent number: 7924102
    Abstract: An oscillator includes a control circuit and a ring of symmetric load delay cells. Each delay cell includes two novel symmetric loads. Each load involves a level shift circuit and a diode-connected transistor coupled in parallel with a current source-connected transistor. The control circuit converts an oscillator input signal into bias control signals that in turn control the effective resistance of the symmetric loads such that delays through the delay cells are a function of the input signal. The control circuit uses a symmetric load replica in a control loop to control the level shift circuits of the delay cells such that the oscillating delay cell output signals have a constant amplitude. In a first advantageous aspect, due to the constant amplitude, the oscillator is operable over a wide frequency range. In a second advantageous aspect, the oscillator input signal to output signal oscillation frequency has a substantially linear relationship.
    Type: Grant
    Filed: February 23, 2009
    Date of Patent: April 12, 2011
    Assignee: QUALCOMM Incorporated
    Inventor: Jeffrey M. Hinrichs
  • Patent number: 7911284
    Abstract: A voltage controlled oscillator circuit comprises a variable current generator to supply an operation current to a voltage controlled oscillator, the voltage controlled oscillator to include a resonance circuit having a variable capacitor and inductor, and to output an output signal having an amplitude based on a current generated by the variable current generator, and a first optimization circuit to which the output signal is inputted, the first optimization circuit generating and outputting a current setting signal based on an amplitude change of the output signal corresponding to a change of a current outputted by the variable current generator to the variable current generator.
    Type: Grant
    Filed: March 21, 2008
    Date of Patent: March 22, 2011
    Assignee: Renesas Electronics Corporation
    Inventor: Akira Kuwano
  • Patent number: 7895894
    Abstract: A driver device includes a gain control amplifier that causes a vibrator to produce driving vibrations by controlling an oscillation amplitude in an oscillation loop, a signal generation circuit that generates a signal having a given frequency, and a modulation circuit that modulates the frequency of the signal generated by the signal generation circuit to a resonance frequency of the vibrator. The driver device causes the vibrator to produce the driving vibrations using the signal modulated by the modulation circuit, and then causes the vibrator to produce the driving vibrations by controlling the oscillation amplitude in the oscillation loop formed by the vibrator and the gain control amplifier.
    Type: Grant
    Filed: November 2, 2007
    Date of Patent: March 1, 2011
    Assignee: Seiko Epson Corporation
    Inventors: Masahiro Kanai, Naoki Yoshida, Eitaro Otsuka
  • Publication number: 20110001571
    Abstract: A crystal oscillator emulator integrated circuit includes a first temperature sensor configured to sense a first temperature of the crystal oscillator emulator integrated circuit. The memory is configured to (i) store calibration parameters and (ii) select at least one of the calibration parameters based on the first temperature. A semiconductor oscillator is configured to generate an output signal, wherein (i) the output signal has a frequency and an amplitude and (ii) the frequency is based on the at least one of the calibration parameters. An amplitude adjustment module is configured to (i) compare the amplitude to a predetermined amplitude and (ii) generate a control signal to adjust the amplitude based on the comparison.
    Type: Application
    Filed: September 7, 2010
    Publication date: January 6, 2011
    Inventor: Sehat Sutardja
  • Patent number: 7863993
    Abstract: An oscillator, including amplifier circuitry and resonant circuitry, for providing an oscillation signal with a controllable frequency while maintaining a substantially constant steady state magnitude. Controllable reactive circuitry, included as part of the amplifier circuitry, has a reactance which can be controlled such that the resistive components of the amplifier circuitry and resonant circuitry impedances remain substantially equal. When in the form of serially coupled, controllable capacitances, the controllable reactive circuitry is controlled such that a ratio of changes in the controllable capacitances is approximately equal to a negative ratio of the capacitance values.
    Type: Grant
    Filed: September 8, 2008
    Date of Patent: January 4, 2011
    Assignee: National Semiconductor Corporation
    Inventors: Mounir Bohsali, Ali Kiaei, Gerard Socci, Masood Yousefi, Ali Djabbari, Ahmad Bahai
  • Patent number: 7863989
    Abstract: A gain control system comprises a reference stage, a bias replication stage, an operational amplifier, an automatic gain control block, a gain stage, and a crystal oscillator in one embodiment. A negative feedback loop is formed by portions of the operational amplifier, the replica biasing stage, the gain stage, and the automatic gain control stage. The negative feedback loop operatively controls an amplitude of oscillation in the crystal oscillator. The automatic gain control block produces output currents at reference levels in proportion to an input current source. The output current reference levels provide a corresponding yet independent scaling of currents in the bias replication stage and the gain stage. By the scaling capabilities provided a high common mode of voltage is provided between the crystal oscillator and the voltage reference section while stable oscillating characteristics are provided over a broad frequency range.
    Type: Grant
    Filed: March 10, 2009
    Date of Patent: January 4, 2011
    Assignee: Spectra Linear, Inc.
    Inventors: Omer Fatih Orberk, Alexei Shkidt
  • Patent number: 7855606
    Abstract: An oscillator device having an oscillation system including an oscillator and a resilient supporting member, a driving member configured to supply a driving force to the oscillation system based on a driving signal, a detecting member configured to detect at least an oscillation amplitude of the oscillator, a driving amplitude control unit configured to control at least a driving amplitude of the driving signal, and a driving frequency control unit configured to control a driving frequency of the driving signal to be supplied to the driving member, wherein, in a state in which the driving amplitude control unit controls the driving amplitude of a driving signal so that the oscillation amplitude to be detected becomes equal to a target value, and on the basis of information including driving frequencies in different driving states being driven with driving signals of these driving frequencies as well as the controlled driving amplitude, the driving frequency control unit acquires, as a resonance frequency of t
    Type: Grant
    Filed: February 17, 2009
    Date of Patent: December 21, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventor: Kazufumi Onuma
  • Patent number: 7849746
    Abstract: A driver device that forms an oscillation loop with a vibrator and causes the vibrator to produce driving vibrations includes a current-voltage converter that is provided in the oscillation loop and converts a current that flows through the vibrator into a voltage, and a GCA as a comparator that is provided in the oscillation loop and outputs a signal corresponding to a comparison result between an output from the current-voltage converter and a given voltage. The GCA outputs a first high-level voltage or a low-level voltage during oscillation startup, and outputs a second high-level voltage or the low-level voltage in a steady oscillation state. The first high-level voltage is a voltage higher in potential than the second high-level voltage.
    Type: Grant
    Filed: November 26, 2007
    Date of Patent: December 14, 2010
    Assignee: Seiko Epson Corporation
    Inventors: Masahiro Kanai, Naoki Yoshida, Eitaro Otsuka
  • Patent number: 7839230
    Abstract: Provided is a PLL oscillation circuit that can reduce the variability of modulation sensitivity of a VCO 101 and obtain a desired output amplitude quickly with high precision. An amplitude detector 103 detects an output amplitude of the VCO 101. An amplitude controller 105 controls a current value of a variable current source 109 so as to have an output amplitude of the VCO 101 detected by the amplitude detector 103 to be a desired amplitude. A LPF 108 is connected between the amplitude controller 105 and the variable current source 109. A switch 107 connects or disconnects the LPF 108 between the amplitude controller 105 and the variable current source 109. The amplitude controller 105 is connected to the variable current source 109 through either the LPF 108 or the switching switch 107.
    Type: Grant
    Filed: May 20, 2009
    Date of Patent: November 23, 2010
    Assignee: Panasonic Corporation
    Inventors: Masakatsu Maeda, Takayuki Tsukizawa, Hiroyuki Yoshikawa, Shunsuke Hirano
  • Patent number: 7808334
    Abstract: An oscillation driver circuit that drives a physical quantity transducer includes a one-input/two-output comparator. The one-input/two-output comparator includes a shared differential section that compares a voltage signal input from a drive current/voltage conversion amplifier circuit with a given voltage, a first output section that receives a signal output from the differential section, variably adjusts a voltage amplitude of the received signal, and outputs the resulting signal, and a second output section that receives the signal output from the differential section, and outputs a synchronous detection reference signal of which the voltage amplitude is fixed.
    Type: Grant
    Filed: July 22, 2008
    Date of Patent: October 5, 2010
    Assignee: Seiko Epson Corporation
    Inventors: Naoki Yoshida, Masahiro Kanai, Eitaro Otsuka
  • Patent number: 7756487
    Abstract: A novel and useful apparatus for and method of local oscillator (LO) generation with non-integer multiplication ratio between the local oscillator and RF frequencies. The LO generation schemes presented are operative to generate I and Q square waves at a designated frequency while avoiding the well known issue of harmonic pulling. The input signal is fed to a synthesizer timed to a rational multiplier of the RF frequency L/N fRF. The clock signal generated is divided by a factor Q to form 2Q phases of the clock at a frequency of L(N*Q)fRF, wherein each phase undergoes division by L. The phase signals are input to a pulse generator which outputs a plurality of pulses. The pulses are input to a selector which selects which signal to output at any point in time. By controlling the selector, the output clock is generated as a TDM based signal. Any spurs are removed by an optional filter.
    Type: Grant
    Filed: August 24, 2007
    Date of Patent: July 13, 2010
    Assignee: Texas Instruments Incorporated
    Inventors: Gregory Lerner, Nir Tal, Robert B. Staszewski
  • Publication number: 20100171561
    Abstract: An oscillator including: a first complementary differential amplifier (CDA) outputting a first output signal obtained by amplifying signals input to a first input terminal and a second input terminal of the first CDA; and a second CDA outputting a second output signal obtained by amplifying signals input to a first input terminal and a second input terminal of the second CDA, the second output signal having a differential phase with respect to the first output signal, wherein the first CDA may include an output terminal connected to the first input terminal and the second input terminal of the second CDA and the second CDA may include an output terminal connected to the first input terminal and the second input terminal of the first CDA.
    Type: Application
    Filed: January 8, 2010
    Publication date: July 8, 2010
    Inventor: Chan-kyung Kim
  • Publication number: 20100127786
    Abstract: An oscillator having: a transistor; a resonant circuit coupled between an output electrode of the transistor and a control electrode of the transistor; and a dc bias circuit for the transistor. The dc bias circuit comprises: a voltage producing circuit and a differential amplifier. The differential amplifier includes: a first input coupled to a fixed reference voltage; a second input coupled to the voltage producing circuit, such voltage producing circuit producing a voltage at the second input of the difference amplifier related to current passing through the output electrode of the transistor; and an output coupled to the control electrode of the transistor.
    Type: Application
    Filed: November 24, 2008
    Publication date: May 27, 2010
    Inventors: Roger L. Clark, William W. Cooper, Mark J. Gugliuzza
  • Patent number: 7724101
    Abstract: A crystal oscillator circuit includes a capacitive load stage coupled to a crystal; an amplifier stage including an amplifying transistor coupled to the crystal and to the capacitive load stage for establishing an oscillation signal at the amplifier stage output and a bias generator stage coupled to the amplifying transistor; an amplitude control stage to control the amplitude of the oscillation signal; a pick-up stage coupled to the amplifier stage and to the crystal to generate an oscillator output signal. The bias generator stage is configured as a degenerated common source amplifier.
    Type: Grant
    Filed: April 7, 2008
    Date of Patent: May 25, 2010
    Assignee: Texas Instruments Deutschland GmbH
    Inventor: Rodrigo M. Guerreiro
  • Patent number: 7714674
    Abstract: The integrated circuit package includes a processing core for operating on a set of instructions to carry out predefined processes. A real time clock circuit provides a system clock for the processing core. The real time clock further comprises an internal oscillator that generates the system clock for the integrated circuit package. The internal oscillator has a factory calibrated bias current. An internal oscillator control register controls the operation of the internal oscillator responsive to control bits of the programmable load capacitor array controlled by the processing core.
    Type: Grant
    Filed: December 31, 2007
    Date of Patent: May 11, 2010
    Assignee: Silicon Laboratories Inc.
    Inventors: Xiaoling Guo, Alan L. Westwick
  • Patent number: 7696834
    Abstract: A voltage-controlled oscillator includes: a bias voltage generator operating to generate first and second bias voltages in response to a control signal; a voltage-controlled oscillation circuit connected to a control node and configured to generate oscillation signals in response to an input voltage; a selection signal generator operating to generate a selection signal in response each to the oscillation signals; and a selection circuit operating to select one of the first and second bias voltages in response to the selection signal and outputting the selected bias voltage to the control node.
    Type: Grant
    Filed: June 4, 2007
    Date of Patent: April 13, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Ki-Hyuk Sung
  • Patent number: 7692506
    Abstract: An oscillation driver device includes a gain control amplifier, an automatic gain control circuit, and a mode setting circuit. When the mode setting circuit has switched a mode from a normal operation mode to a low power consumption mode, the automatic gain control circuit is disabled, and the gain in an oscillation loop that drives the vibrator changes from a state in which the gain in the oscillation loop is controlled to be unity by the automatic gain control circuit to a state in which the gain in the oscillation loop is set to be larger than unity. When the mode setting circuit has switched the mode from the low power consumption mode to the normal operation mode, the automatic gain control circuit resumes operation, and the gain in the oscillation loop changes from the state in which the gain in the oscillation loop is set to be larger than unity to the state in which the gain in the oscillation loop is controlled to be unity by the automatic gain control circuit.
    Type: Grant
    Filed: July 28, 2008
    Date of Patent: April 6, 2010
    Assignee: Seiko Epson Corporation
    Inventors: Masahiro Kanai, Eitaro Otsuka, Naoki Yoshida
  • Patent number: 7688153
    Abstract: The present invention relates to an oscillating circuit arrangement having a resonating arrangement with a first resonance frequency (coo) comprising a voltage controlled oscillator arrangement. It further comprises a tunable filter arrangement connected to the source node of said voltage controlled oscillator (VCO) arrangement. Said filter arrangement particularly comprises an equivalent current source resonating at a second resonance frequency c?f, the second resonance frequency being a multiple n, n=1 or 2 of said first resonance frequency (?>o), n being equal to the minimum number of switch transistors required for oscillation of said VCO arrangement. The filter arrangement particularly comprises an inductor connected in parallel with a capacitor, said capacitor being adapted to be tunable such that the phase noise of the resonating arrangement can be minimized through tuning of the filter arrangement.
    Type: Grant
    Filed: October 5, 2005
    Date of Patent: March 30, 2010
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Harald Jacobsson, Lars Aspemyr
  • Patent number: 7688154
    Abstract: To maintain the amplitude of an oscillating signal within a defined range, the detected peak level of the oscillating signal is compared to a reference voltage. If the detected peak level is determined as being greater than the reference voltage, the common source/drain voltage of a differential amplifier driving the crystal oscillator across its input terminals is reduced so as to lower the amplitude of the oscillation signal. If the detected peak level is determined as being smaller than the reference voltage, the common source/drain voltage of the differential amplifier driving the crystal oscillator is increase so as to raise the amplitude of the oscillation signal.
    Type: Grant
    Filed: June 21, 2006
    Date of Patent: March 30, 2010
    Assignee: Exar Corporation
    Inventor: Bahram Fotouhi
  • Patent number: 7675374
    Abstract: Provided is a voltage controlled oscillator to which a switching bias technique is applied so as to lower flicker noise of a bias circuit and enhance phase noise characteristics, thereby reducing the overall chip area to make it possible to achieve integration. A common mode voltage applied to the bias circuit is negatively fed back to an oscillation waveform. Therefore, it is possible to stabilize the magnitude of the oscillation waveform of the voltage controlled oscillator with respect to a change in an external condition.
    Type: Grant
    Filed: April 29, 2008
    Date of Patent: March 9, 2010
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Byung Hun Min, Young Ho Kim, Byoung Gun Choi, Seok Bong Hyun
  • Publication number: 20100001804
    Abstract: A system to improve a voltage-controlled oscillator may include a voltage-controlled oscillator. The system may also include a switch to control a first voltage passing through the voltage-controlled oscillator based upon a digital tune bit used to control the voltage-controlled oscillator's gain.
    Type: Application
    Filed: July 6, 2008
    Publication date: January 7, 2010
    Inventors: David M. Friend, George E. Smith, III, Michael Sperling, James D. Strom
  • Patent number: 7639097
    Abstract: In one embodiment, a method of programming an oscillator circuit includes providing a resonator, a first programmable capacitor, a second programmable capacitor, and an amplifier. The first programmable capacitor and the second programmable capacitor may be programmed at a first capacitance value during a first time period, wherein the first programmable capacitor provides a first voltage to bias the resonator and the amplifier alters the second voltage to provide a third voltage to the resonator. During a second time period the first capacitance value is increased.
    Type: Grant
    Filed: October 11, 2007
    Date of Patent: December 29, 2009
    Assignee: Freescale Semiconductor, Inc.
    Inventor: Daniel N. Tran
  • Publication number: 20090284320
    Abstract: This invention discloses a clock generator capable of automatically adjusting output clock when process, voltage, or temperature variation occurred. The clock generator comprises a current generator, for generating a first current and a second current according to a control voltage; a oscillator, coupled to the current generator, for generating a clock signal according to the first current; and a voltage adjuster, coupled to the current generator and the oscillator, for adjusting the control voltage according to the clock signal and the second current; wherein, when the signal frequency of the clock signal changed, the voltage adjuster correspondingly adjusts the control voltage so as to adjust the first current.
    Type: Application
    Filed: May 14, 2009
    Publication date: November 19, 2009
    Inventors: Chen-Chih HUANG, TSUNG YEN TSAI
  • Publication number: 20090273405
    Abstract: A voltage controlled oscillator and a method of operating a voltage-controlled oscillator are disclosed. The oscillator comprises a current controlled oscillator having a variable frequency current output, a first control path for generating a first control current having a first adjustable gain, and a second control path for generating a second control current having a second adjustable gain. A summer is provided for adding the first and second control currents to obtain a summed control current, and for applying the summed control current as an input current to the current controlled oscillator. A control sub-circuit is used for controlling the gain of the first control current as a function of a defined voltage on the second control path to maintain constant the gain of the current output of the current controlled oscillator over a given operating range of the current controlled oscillator.
    Type: Application
    Filed: May 2, 2008
    Publication date: November 5, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Glenn E. R. Cowan, Daniel J. Friedman, Mounir Meghelli
  • Patent number: 7598821
    Abstract: The invention concerns an oscillator including an input terminal, an output terminal, a resonator, and an oscillator circuit including: first and second power supply terminals, two capacitors connected between the first power supply terminal and the input terminal, and respectively the output terminal of the oscillator; first and second active transistors of complementary type, forming therewith an inverting amplifier, first and second means for respectively polarizing the first and the second active transistors, a first current source formed by a transistor of the same type as the second active transistor, between the second power supply terminal and the second active transistor, current control means for the second polarizing means, characterized in that in an steady operating conditions, said second polarizing means are arranged for providing a polarization voltage across the gate of the second active transistor corresponding to the transistor gate voltage of the first current source to within one voltage
    Type: Grant
    Filed: October 29, 2007
    Date of Patent: October 6, 2009
    Assignee: EM Microelectronic-Marin S.A.
    Inventor: Pinchas Novac
  • Patent number: 7557666
    Abstract: An oscillation circuits includes an oscillation unit 30 for generating an internal clock signal having an amplitude of vibration corresponding to an internal power supply voltage thereof, switches 28, 29, a NMOS 13 of a tolerant input circuit, a first-stage driver 15, and a coupling capacitance 27. The switches 28, 29 are turned off when the external clock signal is inputted to a clock terminals 1, 2, and are turned on when the oscillation unit 30 oscillates. The NMOS 13 changes the amplitude of the input clock signal by the on-resistance and the outputs the above input clock signal from the drain electrode. The first-stage driver 15 drives the output of the drain electrode of the NMOS 13 and outputs the output thereof as a clock signal. The coupling capacitance 27 changes the gate voltage of the NMOS 13 when the input clock signal rises so as to keep the above on-resistance constant.
    Type: Grant
    Filed: March 1, 2007
    Date of Patent: July 7, 2009
    Assignee: Oki Semiconductor Co., Ltd.
    Inventor: Kenichirou Sugio
  • Patent number: 7554416
    Abstract: Provided is an LC resonance voltage-controlled oscillator (VCO) used for a multi-band multi-mode wireless transceiver. In order to generate a multi-band frequency, a capacitor bank and a switchable inductor are included in the LC resonance voltage-controlled oscillator. The LC resonance voltage-controlled oscillator employs an adjustable emitter-degeneration negative resistance cell in place of tail current sources in order to compensate for non-uniform oscillation amplitude caused by the capacitor bank and prevent the degradation of a phase noise due to the tail current sources.
    Type: Grant
    Filed: October 2, 2006
    Date of Patent: June 30, 2009
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Ja Yol Lee, Kwi Dong Kim, Chong Ki Kwon, Jong Dae Kim, Sang Heung Lee, Kyoung Ik Cho
  • Publication number: 20090146748
    Abstract: Exemplary embodiments of the invention provide a reference signal generator, system and method. An exemplary apparatus to generate a harmonic reference signal includes a reference resonator, such as an LC-tank, and an amplitude controller. The reference resonator generates a first reference signal having a resonant frequency, and the amplitude controller maintains substantially constant a magnitude of a peak amplitude of the first reference signal. A common mode controller may also be included to maintain substantially constant a common mode voltage level of the reference resonator. A temperature-dependent control voltage also may be generated and utilized to maintain the resonant frequency substantially constant or within a predetermined variance of a calibrated or selected frequency.
    Type: Application
    Filed: January 12, 2008
    Publication date: June 11, 2009
    Applicant: MOBIUS MICROSYSTEMS, INC.
    Inventors: Scott Michael Pernia, Michael Shannon McCorquodale, Nam Duc Nguyen, Justin O'Day, Ralph Beaudouin, Sundus Kubba
  • Publication number: 20090085680
    Abstract: Disclosed is an oscillator including a reference voltage generator generating a reference voltage, and a logic combination circuit generating complementary first and second internal clock signals in response to the reference voltage and complementary first and second output voltages. One of the first and second output voltages—the one going high—is provided to the logic combination circuit before the other one of the first and second output voltages—the one going low.
    Type: Application
    Filed: September 26, 2008
    Publication date: April 2, 2009
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventor: Bo-Geun KIM
  • Publication number: 20090033432
    Abstract: An oscillation driver device includes a gain control amplifier, an automatic gain control circuit, and a mode setting circuit. When the mode setting circuit has switched a mode from a normal operation mode to a low power consumption mode, the automatic gain control circuit is disabled, and the gain in an oscillation loop that drives the vibrator changes from a state in which the gain in the oscillation loop is controlled to be unity by the automatic gain control circuit to a state in which the gain in the oscillation loop is set to be larger than unity. When the mode setting circuit has switched the mode from the low power consumption mode to the normal operation mode, the automatic gain control circuit resumes operation, and the gain in the oscillation loop changes from the state in which the gain in the oscillation loop is set to be larger than unity to the state in which the gain in the oscillation loop is controlled to be unity by the automatic gain control circuit.
    Type: Application
    Filed: July 28, 2008
    Publication date: February 5, 2009
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Masahiro KANAI, Eitaro Otsuka, Naoki Yoshida
  • Patent number: 7471163
    Abstract: An oscillator circuit includes a plurality of transistors that can withstand relatively low gate-to-source and gate-to-drain voltages. The oscillator circuit interfaces with an oscillator that oscillates at a relatively high voltage. The oscillator circuit includes a first set of transistors coupled to an input voltage and an output voltage of the oscillator, the input voltage oscillating in a range exceeding a tolerance voltage level of each transistor of the first set of transistors. The oscillator circuit also includes a second set of transistors to limit a voltage level in the first set of transistors. The oscillator circuit further includes a third set of transistors to provide a constant current path for the second set of transistors, independent of a switching state of each transistor of the first set of transistors.
    Type: Grant
    Filed: September 29, 2006
    Date of Patent: December 30, 2008
    Assignee: Intel Corporation
    Inventors: Alan Eah Loon Chuah, Syn Pui Law
  • Publication number: 20080266006
    Abstract: Provided is a voltage controlled oscillator to which a switching bias technique is applied so as to lower flicker noise of a bias circuit and enhance phase noise characteristics, thereby reducing the overall chip area to make it possible to achieve integration. A common mode voltage applied to the bias circuit is negatively fed back to an oscillation waveform. Therefore, it is possible to stabilize the magnitude of the oscillation waveform of the voltage controlled oscillator with respect to a change in an external condition.
    Type: Application
    Filed: April 29, 2008
    Publication date: October 30, 2008
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Byung Hun MIN, Young Ho Kim, Byoung Gun Choi, Seok Bong Hyun
  • Publication number: 20080246547
    Abstract: A high frequency power device (100) is described comprising a high frequency power transistor (102) having a first main electrode, a second main electrode acting as output electrode and a control electrode, and an output compensation circuit (104) for compensating parasitic output capacitance of the transistor (102). The output compensation circuit is physically positioned relative to the transistor such that a shorter bond wire between the output electrode of the transistor and an output lead of the high frequency power device is obtained. The output compensation circuit (104) therefore is physically located in between an input lead (108) of the high frequency power device (100) and the transistor (102). The inductance introduced by the bond wire Lcomp from the output compensation circuit (104) to the output electrode of the transistor (102) can be used as a feedback signal.
    Type: Application
    Filed: March 14, 2006
    Publication date: October 9, 2008
    Applicant: NXP B.V.
    Inventor: Igor Blednov
  • Publication number: 20080238559
    Abstract: A voltage controlled oscillator circuit comprises a variable current generator to supply an operation current to a voltage controlled oscillator, the voltage controlled oscillator to include a resonance circuit having a variable capacitor and inductor, and to output an output signal having an amplitude based on a current generated by the variable current generator, and a first optimization circuit to which the output signal is inputted, the first optimization circuit generating and outputting a current setting signal based on an amplitude change of the output signal corresponding to a change of a current outputted by the variable current generator to the variable current generator.
    Type: Application
    Filed: March 21, 2008
    Publication date: October 2, 2008
    Applicant: NEC Electronics Corporation
    Inventor: Akira KUWANO
  • Patent number: 7372342
    Abstract: A high-performance crystal oscillator providing effective bias resistors with low power consumption and minimal substrate surface area. In various embodiments of the invention, a switched-capacitor resistor is operably coupled to circuit components, such as an oscillation source, a current source, an input buffer, or an amplifier to provide a bias resistance.
    Type: Grant
    Filed: July 31, 2006
    Date of Patent: May 13, 2008
    Assignee: Freescale Semiconductor, Inc.
    Inventor: Michael Berens
  • Patent number: 7355489
    Abstract: An oscillator amplifier circuit is provided. The amplifier circuit can be used with a resonator to amplify and form a resonating oscillator. The amplifier circuit comprises an active circuit which includes an inverter and a current-controlled biasing circuit. One transistor of the inverter receives a voltage produced from the biasing circuit in order to place a gate terminal of that transistor at approximately a threshold voltage. The other transistor can be biased using a passive circuit element, such as a resistor. Therefore, both transistors are biased independent of each other within the optimal gain region. Large shunt capacitors are not required and the total current consumption is controlled through a variable resistor coupled to the source terminal of either the first transistor, second transistor, or possibly both transistors of the inverter to adjust the amplitude of the oscillating output.
    Type: Grant
    Filed: February 10, 2006
    Date of Patent: April 8, 2008
    Assignee: Cypress Semiconductor Corp.
    Inventor: Sanjeev Kumar Maheshwari
  • Publication number: 20080079506
    Abstract: An oscillator circuit includes a plurality of transistors that can withstand relatively low gate-to-source and gate-to-drain voltages. The oscillator circuit interfaces with an oscillator that oscillates at a relatively high voltage. The oscillator circuit includes a first set of transistors coupled to an input voltage and an output voltage of the oscillator, the input voltage oscillating in a range exceeding a tolerance voltage level of each transistor of the first set of transistors. The oscillator circuit also includes a second set of transistors to limit a voltage level in the first set of transistors. The oscillator circuit further includes a third set of transistors to provide a constant current path for the second set of transistors, independent of a switching state of each transistor of the first set of transistors.
    Type: Application
    Filed: September 29, 2006
    Publication date: April 3, 2008
    Inventors: Alan Eah Loon Chuah, Syn Pui Law
  • Publication number: 20080068097
    Abstract: A voltage-controlled oscillator includes: a bias voltage generator operating to generate first and second bias voltages in response to a control signal; a voltage-controlled oscillation circuit connected to a control node and configured to generate oscillation signals in response to an input voltage; a selection signal generator operating to generate a selection signal in response each to the oscillation signals; and a selection circuit operating to select one of the first and second bias voltages in response to the selection signal and outputting the selected bias voltage to the control node.
    Type: Application
    Filed: June 4, 2007
    Publication date: March 20, 2008
    Inventor: Ki-Hyuk Sung
  • Patent number: 7339441
    Abstract: An OTA driving an MOS device needs to turn it off quickly to minimize overshoot during a heavy to light load state. The drains of the MOS device can be used to accelerate turning off the MOS device. A first drain is connected to the gate of the MOS device. A second drain is connected to a base of a bipolar device. The emitter of the bipolar device is connected to the MOS device gate. Notably, this bipolar device is active during the heavy to light load state. Therefore, any current provided by the second drain is then multiplied by the beta of the bipolar device. The increased current generated on the emitter of the bipolar transistor and provided to the gate of the MOS device can advantageously accelerate the turnoff of that MOS device. The first drain can provide minimal additional current during the heavy to light load state.
    Type: Grant
    Filed: March 20, 2006
    Date of Patent: March 4, 2008
    Assignee: Micrel, Incorporated
    Inventor: Michael J. Mottola
  • Patent number: 7123109
    Abstract: An oscillator circuit may be operated in a high power mode or a reduced power mode. The high power mode provides fast start-up of the oscillator circuit.
    Type: Grant
    Filed: December 15, 2004
    Date of Patent: October 17, 2006
    Assignee: Intel Corporation
    Inventors: Paul E. Stevenson, Jon E. Tourville, Nathan L. Pihlstrom
  • Patent number: 7061337
    Abstract: An amplitude control circuit comprises a first circuit configured to receive differential signals and provide a first signal based on the amplitudes of the differential signals, a second circuit configured to receive a bias signal and provide a second signal based on the bias signal, and a third circuit configured to provide bias to the first circuit and the bias signal to the second circuit. The bias signal is set to provide selected amplitudes of the differential signals.
    Type: Grant
    Filed: July 14, 2004
    Date of Patent: June 13, 2006
    Assignee: Infineon Technologies AG
    Inventors: Hamid Partovi, Sivaraman Chokkalingam, Karthik Gopalakrishnan
  • Patent number: 7061338
    Abstract: Circuits and methods are given, to realize and implement an oscillator circuit with an Average Controlled (AC) Resonator Driver. A newly introduced additional Field Effect Transistor within a voltage average stabilizing regulation loop controlling the crystal oscillator's amplifier element produces an average voltage value stabilized sinusoidal oscillation signal which is then transformed into a square wave with a precise duty-cycle of exactly 50%. Said circuits and methods are designed in order to be implemented with a very economic number of components, capable to be realized with modern integrated circuit technologies.
    Type: Grant
    Filed: October 1, 2004
    Date of Patent: June 13, 2006
    Assignee: Dialog Semiconductor GmbH
    Inventor: Antonello Arigliano
  • Patent number: 7038550
    Abstract: A circuit and a method are given, to realize and implement an oscillator circuit with a Smart Current Controlled (SCC) Resonator Driver. A newly introduced controlled current source for a crystal oscillator's amplifier element produces a controlled driving current for the resonator element during operation in both phases of the oscillation cycle to reach for low phase noise and reduced power consumption of the circuit. Said circuit and method are designed in order to be implemented with a very economic number of components, capable to be realized with modern integrated circuit technologies.
    Type: Grant
    Filed: October 1, 2004
    Date of Patent: May 2, 2006
    Assignee: Dialog Semiconductor GmbH
    Inventor: Antonello Arigliano
  • Patent number: 7026883
    Abstract: A voltage-controlled oscillator includes an inductor capacitor (LC) tank; a drive circuit having a current source; and a feedback loop circuit. The feedback loop includes a peak detect circuit to generate a peak detect voltage; a reference voltage generator to generate a single reference voltage; and an operational amplifier, coupled to the peak detect circuit and the reference voltage generator, to generate an analog bias signal to adjust a current of the current source.
    Type: Grant
    Filed: March 12, 2004
    Date of Patent: April 11, 2006
    Assignee: Intel Corporation
    Inventors: Harish Muthali, Ian Young, Joseph F. Ahadian
  • Patent number: 7002421
    Abstract: A method for tracking the MOS oxide thickness by the native threshold voltage of a “native” MOS transistor without channel implantation for the purpose of compensating MOS capacitance variations is achieved. The invention makes use of the fact that in MOS devices the threshold voltage is proportionally correlated to the oxide thickness of said MOS device. Said threshold voltage can therefore be used to build a reference voltage Vx+Vth which accurately tracks the MOS capacitance variations in integrated circuits. Circuits are achieved to create a frequency reference and a capacitance reference using said method Additionally a method is introduced to create a capacitance reference in integrated circuits using said MOSFET capacitors.
    Type: Grant
    Filed: June 16, 2004
    Date of Patent: February 21, 2006
    Assignee: Dialog Semiconductor GmbH
    Inventor: Matthias Eberlein