With Means To Limit Crystal Current Or Voltage Patents (Class 331/160)
  • Patent number: 10461071
    Abstract: Certain aspects of the disclosure are directed to electrostatic discharge protection of an integrated circuit clock. According to a specific example, circuitry includes a direct-current power supply, a voltage-controlled oscillation (VCO) circuit, an electrostatic protection circuit, and a voltage regulator. The VCO circuit has an oscillation frequency and includes an amplification circuit and capacitance circuitry. The electrostatic protection circuit is arranged to connect power to the VCO circuit while reducing variation in the oscillation frequency of the VCO circuit resulting from electrostatic energy. The voltage regulator is connected between the direct-current power supply and a power supply connection at which the direct-current power is connected to the VCO, and is configured to mitigate an imbalance of electric charges from adversely altering a tuning capacitance of the VCO established by the capacitance circuitry.
    Type: Grant
    Filed: February 3, 2017
    Date of Patent: October 29, 2019
    Assignee: NXP B.V.
    Inventor: Alastair Hopper
  • Patent number: 9000852
    Abstract: Aspects of the disclosure provide a circuit. The circuit includes a signal amplifying circuit coupled with a crystal component of a natural frequency to form a crystal oscillator, and a signal generator circuit configured to generate a signal with an energy distribution about the natural frequency, and to provide the signal to the crystal oscillator to assist the crystal oscillator to begin oscillating.
    Type: Grant
    Filed: November 8, 2012
    Date of Patent: April 7, 2015
    Assignee: Marvell International Ltd.
    Inventors: Dennis Sinitsky, Junshi Qiao, Pei Wang, Song Chen, Haiqing Zhang, Tao Shui
  • Patent number: 8952762
    Abstract: A clock generator includes, in part, a buffer, a peak detector and a control logic. The buffer generates a clock output signal in response to receiving a clock signal and a feedback signal that controls the gain of the buffer. If the peak detector detects that the amplitude of the output signal is higher than the upper bound of the predefined range, the gain value applied to the variable buffer is decreased. If the peak detector detects that the amplitude of the output signal is lower than the lower bound of the predefined range, the gain value applied to the variable buffer to increased. If the peak detector detects that the amplitude of the output signal is within the predefined range, no change is made to the gain value applied to the variable buffer. The control logic generates the feedback signal in response to the peak detector's output signal.
    Type: Grant
    Filed: November 22, 2010
    Date of Patent: February 10, 2015
    Assignee: MaxLinear, Inc.
    Inventor: Tomas O'Sullivan
  • Patent number: 8884711
    Abstract: A MEMS device and method for amplitude regulation of a MEMS device are disclosed. In a first aspect, the MEMS device comprises a MEMS resonator, a limiter coupled to the MEMS resonator, and a regulator coupled to the limiter. The MEMS device includes an amplitude control circuit coupled to the MEMS resonator. The amplitude control circuit controls a supply of the limiter via the regulator to regulate oscillation loop amplitude of the MEMS device. In a second aspect, the method includes coupling a regulator to the limiter, coupling an amplitude control circuit to the MEMS resonator, and controlling a supply of the limiter via the regulator to regulate oscillation loop amplitude of the MEMS device.
    Type: Grant
    Filed: September 24, 2012
    Date of Patent: November 11, 2014
    Assignee: InvenSense, Inc.
    Inventor: Vadim Tsinker
  • Patent number: 8854147
    Abstract: A crystal oscillator may be configured to limit crystal drive level in the crystal oscillator by clamping via a diode-resistor branch, voltage applied to a drain pad of the crystal oscillator. The crystal oscillator may incorporate Pierce crystal oscillator based implementation. The crystal oscillator may comprise an on-chip main branch, comprising at least one transistor element; an on-chip drain branch connecting the main branch to a drain pad; an on-chip gate branch connecting the main branch to a gate pad. The diode-resistor branch may be connected to the drain branch, and may comprise at least one diode and at least one resistor element. The at least one diode and the at least one resistor element may be connected in series in the diode-resistor branch. The clamped voltage may be applied from an off-chip drain node, through the drain pad.
    Type: Grant
    Filed: October 12, 2012
    Date of Patent: October 7, 2014
    Assignee: Google Inc.
    Inventor: Cheng-Yi Andrew Lin
  • Patent number: 8816786
    Abstract: A large gain is used to start up the oscillation of the crystal quickly. Once the oscillation starts, the amplitude is detected. A control circuit determines based on the measured amplitude to disable a low resistance path in the controlled switch array to reduce the applied gain below the power dissipation specification of the crystal. Another technique introduces a mixed-signal controlled power supply multi-path resistive array which tailors the maximum current to the crystal. A successive approximation register converts the amplitude into several partitions and enables/disables one of several power routing paths to the inverter of the oscillator. This allows a better match between the crystal selected by the customer and the on-chip drive circuitry to power up the oscillator without stressing the crystal. The “l/f” noise of the oscillator circuit is minimized by operating transistors in the triode region instead of the linear region.
    Type: Grant
    Filed: October 1, 2012
    Date of Patent: August 26, 2014
    Assignee: Tensorcom, Inc.
    Inventor: KhongMeng Tham
  • Patent number: 8736391
    Abstract: An oscillator circuit includes an amplifier including at least two terminals for receiving a crystal and an automatic amplitude control loop coupled to the amplifier including biasing circuitry switched between a first operational mode and a second operational mode. The first operational mode occurs during an initial time period and the second operational mode occurs after the initial time period is expired. The biasing circuitry includes first and second PMOS transistor circuits, each transistor circuit including an unswitched PMOS transistor and a switched PMOS transistor. Alternatively, the biasing circuitry can include first and second NMOS transistor circuits, each transistor circuit including an unswitched NMOS transistor and a switched NMOS transistor. The biasing circuitry is under control of an internally generated control signal.
    Type: Grant
    Filed: December 28, 2010
    Date of Patent: May 27, 2014
    Assignee: St-Ericsson SA
    Inventors: Shuiwen Huang, Lin Huang
  • Patent number: 8698569
    Abstract: In order to provide a MEMS resonator having a higher Q factor, by suppressing losses in high-frequency signals due to barriers of thin-film lamination portions, in cases where there exist junction interfaces (barriers), such as pn junctions, in AC-current input/output lines for a vibrator (1) and electrodes (2, 3), the MEMS resonator is structured such that a DC current is flowed therethrough along with an AC current at the same time, in order to reduce resistance losses applied to the AC current, wherein there are provided DC bias circuits (22, 23, 24) for continuously flowing DC currents through the junction interfaces, in an input-electrode side and/or output-electrode side.
    Type: Grant
    Filed: January 31, 2012
    Date of Patent: April 15, 2014
    Assignee: Panasonic Corporation
    Inventor: Kunihiko Nakamura
  • Patent number: 8653898
    Abstract: An embodiment of a crystal oscillator circuit includes leakage-current compensation, transconductance enhancement, or both leakage-current compensation and transconductance enhancement. Such an oscillator circuit may draw a reduced operating current relative to a conventional oscillator circuit, and thus may be suitable for battery or other low-power applications.
    Type: Grant
    Filed: June 30, 2011
    Date of Patent: February 18, 2014
    Assignee: STMicroelectronics International N.V.
    Inventors: Abhirup Lahiri, Anurag Tiwari
  • Patent number: 8653901
    Abstract: An oscillator and a control circuit thereof are provided. The control circuit is configured to control an oscillator to adjust the amplitude and the level of an oscillation signal. The control circuit includes a peak amplitude detector, an average voltage detector, and an oscillation controller. The peak amplitude detector is configured to detect the amplitude of the oscillation signal, so as to generate an amplitude value. The average voltage detector is configured to detect the direct current (DC) level of the oscillation signal, so as to generate an average value. The oscillation controller is configured to generate two power signals according to the amplitude value and the average value. The two power signals are provided to the oscillator, so that the oscillator adjusts the amplitude and DC level of the oscillation signal.
    Type: Grant
    Filed: March 23, 2012
    Date of Patent: February 18, 2014
    Assignee: Novatek Microelectronics Corp.
    Inventors: Jia-Shian Tsai, Kuo-Tai Chang
  • Patent number: 8629730
    Abstract: Provided is a temperature compensated oscillator includes an oscillation circuit for oscillating an oscillator. In the oscillator, when an oscillation frequency is changed by a second control signal after being controlled by a first control signal, variation in the oscillation frequency due to a second control signal is set to a fixed amount. The oscillation frequency of the oscillator is controlled on the basis of both the first control signal and the second control signal, but an oscillation amplitude adjusting section is also added, the oscillation amplitude adjusting section allowing the oscillation amplitude of the oscillator to be changed by the second control signal. The oscillator thus allows a fixed amount of oscillation frequency control over a wide range (full range) of oscillation frequency control due to the first control signal.
    Type: Grant
    Filed: December 21, 2010
    Date of Patent: January 14, 2014
    Assignee: Asahi Kasei Microdevices Corporation
    Inventors: Kenji Nemoto, Tamami Furuya
  • Patent number: 8624633
    Abstract: An oscillator circuit includes an oscillator output signal generating circuit configured to generate an oscillator output signal using an oscillator as a resonator, an amplitude detection circuit configured to detect the amplitude of the oscillator output signal and compare the detected amplitude with a threshold; and a boost circuit configured to boost the oscillator output signal according to the result of the comparison at the amplitude detection circuit. The amplitude detection circuit includes an absolute value circuit configured to obtain an absolute value signal of the oscillator output signal, a low-pass filter configured to convert the absolute value signal into a low-frequency signal, and a comparator configured to compare the low-frequency signal with the threshold.
    Type: Grant
    Filed: June 13, 2012
    Date of Patent: January 7, 2014
    Assignee: Mitsumi Electric Co., Ltd.
    Inventors: Minoru Sakai, Takayuki Nakamura, Akira Komiya
  • Patent number: 8618889
    Abstract: There is provided an oscillation drive device that forms an oscillation loop with a vibrator for exciting a driving vibration on the vibrator.
    Type: Grant
    Filed: February 12, 2010
    Date of Patent: December 31, 2013
    Assignee: Seiko Epson Corporation
    Inventors: Naoki Yoshida, Masahiro Kanai
  • Patent number: 8593231
    Abstract: In accordance with some embodiments of the present disclosure, an oscillator may include a crystal resonator and a squaring circuit coupled to the crystal resonator and configured to convert a sinusoidal signal produced by the crystal resonator to a square-wave signal, the squaring circuit comprising a bias circuit configured to transmit a selected bias voltage for the squaring circuit, the selected bias voltage selected from a plurality of potential bias voltages. In accordance with this and other embodiments of the present disclosure, an oscillator may include a crystal resonator, an inverter coupled in parallel with the crystal resonator, and a programmable voltage regulator coupled to the inverter. The programmable voltage regulator may be configured to supply a first supply voltage to the inverter during a startup duration of the oscillator, and supply a second supply voltage to the inverter after the startup duration, wherein the second supply voltage is lesser than the first supply voltage.
    Type: Grant
    Filed: August 20, 2010
    Date of Patent: November 26, 2013
    Assignee: Intel IP Corporation
    Inventors: John Simmons, Kristopher Kaufman
  • Patent number: 8564378
    Abstract: A voltage-controlled oscillating circuit includes a differential amplifying circuit connected to a resonant element such as a quartz crystal element. The differential amplifying circuit includes first and second input terminals connected to the resonant element and also connected respectively to first and second voltage-controlled capacitors. The differential output terminals of the differential amplifying circuit are connected respectively to first and second emitter follower circuits. The output signal of the first emitter follower circuit is fed back to the second input terminal through a third capacitor and a third voltage-controlled capacitor, and the output signal of the second emitter follower circuit is fed back to the second input terminal through a fourth capacitor and a fourth voltage-controlled capacitor. A control voltage is applied to each of the voltage-controlled capacitors.
    Type: Grant
    Filed: March 19, 2012
    Date of Patent: October 22, 2013
    Assignee: Nihon Dempa Kogyo Co., Ltd.
    Inventor: Yutaka Takahashi
  • Patent number: 8487709
    Abstract: An oscillator circuit comprises a piezoelectric vibrator, an amplifier device including inverters provided in a plurality of stages, and an inverter control device. The inverters provided in the plurality of stages includes a performance-variable inverter configured which is operational in both of an initial phase of oscillation startup and a post-startup phase where the oscillation is stabilized and capable of a variable performance depending on whether the initial phase of oscillation startup or the post-startup phase where the oscillation is stabilized, and an ON/OFF inverter which is operational in the initial phase of oscillation startup and disconnected in the post-startup phase where the oscillation is stabilized.
    Type: Grant
    Filed: July 22, 2010
    Date of Patent: July 16, 2013
    Assignee: Panasonic Corporation
    Inventors: Shinji Ishikawa, Ichiro Yamane
  • Patent number: 8427252
    Abstract: A method and apparatus for configuring an oscillator circuit to selectively switch between a low power mode and a normal mode of operation. The oscillator circuit includes an oscillator core in parallel with a dynamically configurable gain circuit. The oscillator core is configured to generate a clock signal. One or more gain elements of the gain circuit can be selectively disabled to reduce the operating power level of the oscillator circuit during a low power mode.
    Type: Grant
    Filed: May 31, 2011
    Date of Patent: April 23, 2013
    Assignee: QUALCOMM Incorporated
    Inventor: Michael P. Mack
  • Patent number: 8362847
    Abstract: Noise immunity of an oscillator circuit is improved by either increasing the oscillation amplitude of the core's oscillating signal or configuring a built-in low pass filter.
    Type: Grant
    Filed: October 14, 2010
    Date of Patent: January 29, 2013
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventor: Tian-Jian Huang
  • Patent number: 8188802
    Abstract: An apparatus for generating an oscillating signal including an oscillator configured to generate the oscillating signal, a controller configured to generate a control signal that controls a characteristic (e.g., amplitude or frequency) of the oscillating signal, and a power supply configured to supply power to the oscillator as a function of the control signal. The power supply may be configured to supply power to the oscillator as a function of the amplitude or frequency of the oscillating signal to improve power efficiency.
    Type: Grant
    Filed: May 29, 2009
    Date of Patent: May 29, 2012
    Assignee: QUALCOMM Incorporated
    Inventor: Jorge A. Garcia
  • Patent number: 8120439
    Abstract: An exemplary fast start-up crystal oscillator with reduced start-up time. The exemplary oscillator reduces the start-up time (i.e., the time taken to attain sustained stable oscillations after the power is turned on) by increasing the negative resistance of a circuit. Increasing the negative resistance increases the rate of growth of the oscillations, thereby reducing start-up time. The exemplary crystal oscillator includes a gain stage with negative resistance. A crystal with shunt capacitance is placed in the feedback loop of the gain stage. A buffer is coupled to the gain stage such that it blocks the crystal shunt capacitance from loading the gain stage, effectively increasing the negative resistance of the gain stage. Further, an oscillation detection and control circuit is coupled between the crystal and the gain stage. The oscillation detection and control circuit connects the buffer during start-up, and disconnects the buffer once an oscillation signal attains sustained stable oscillations.
    Type: Grant
    Filed: August 13, 2009
    Date of Patent: February 21, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Aatmesh Shrivastava, Rajesh Yadav, Parvinder Kumar Rana
  • Patent number: 8102217
    Abstract: An oscillator creates a reference voltage based on a pulse signal corresponding to an oscillation output of a crystal oscillation circuit and controls a supply voltage to the crystal oscillation circuit according to the reference voltage. A control signal creating circuit creates a control signal based on the pulse signal and reference voltage generating circuits that control the reference voltage based on the control signal. The control signal creating circuit creates a low-level control signal when the pulse signal is in a low level, creates a high-level control signal when the pulse signal is in a high level, and prevents transition of the control signal from the high level to the low level.
    Type: Grant
    Filed: November 30, 2009
    Date of Patent: January 24, 2012
    Assignee: Renesas Electronics Corporation
    Inventor: Hiroyuki Aoki
  • Patent number: 8072278
    Abstract: An apparatus for generating an oscillating signal including a negative-resistance circuit, a crystal, and a component to modify a series resonance of the crystal to decrease power consumption of the negative-resistance circuit in generating the oscillating signal. The component may include a positive-reactance circuit, one or more inductive elements, or pair of inductive elements coupled to the crystal. The apparatus may further include a frequency-tuning component for adjusting a frequency of the oscillating signal, such as a variable capacitor coupled to the crystal. The negative-resistance circuit may include a digital inverter circuit, an inverting analog amplifier, or a self-regulating circuit.
    Type: Grant
    Filed: May 18, 2009
    Date of Patent: December 6, 2011
    Assignee: QUALCOMM Incorporated
    Inventors: Jorge A. Garcia, Todd Moyer
  • Patent number: 8067993
    Abstract: There is provided a constant current driven oscillating circuit including: an oscillator with first and second ends; a first field effect transistor that turns ON when a signal of a lower level than a first threshold voltage is input to a first gate terminal, and outputs, from a second terminal, current that has been input from a first terminal; a second field effect transistor turning ON when a signal output from the oscillator and is at a higher level than a second threshold voltage is input to a second gate terminal connected to the second end of the oscillator, and outputs, from a fourth terminal, current that has been input from a third terminal connected to the second terminal and to the first end of the oscillator; and an adjusting section that adjusts the first threshold voltage according to the level of the signal output from the oscillator.
    Type: Grant
    Filed: January 7, 2010
    Date of Patent: November 29, 2011
    Assignee: Oki Semiconductor Co., Ltd.
    Inventor: Kouji Nasu
  • Patent number: 8054138
    Abstract: This invention makes it possible to reduce a power consumption of an electronic circuit (microcomputer, for example) while preventing malfunctioning of an oscillator by appropriately setting a power supply impedance of a low frequency oscillator corresponding to an operation mode. A high frequency oscillator, a medium frequency oscillator and a low frequency oscillator are provided as sources of system clocks. In addition, there is provided a quartz oscillator to generate a clock for a timepiece. When the high frequency oscillator is in operation, a power supply impedance of the quartz oscillator is reduced to improve a noise tolerance. In a waiting period during which the high frequency oscillator, the medium frequency oscillator and the low frequency oscillator are halted, on the other hand, the power supply impedance of the quartz oscillator is increased to suppress the power consumption.
    Type: Grant
    Filed: January 27, 2010
    Date of Patent: November 8, 2011
    Assignee: Semiconductor Components Industries, LLC
    Inventor: Hideo Kondo
  • Patent number: 8044731
    Abstract: There is provided an oscillator circuit including: a current source; a resonant unit; an oscillation amplification unit connected to the current source and connected in parallel to the resonant unit; a feedback resistor connected in parallel to the oscillation amplification unit; a switch unit having a first end connected to the current source side of the oscillation amplification unit; a replica circuit connected between a second end of the switch unit and a ground side of the oscillation amplification unit and having a configuration identical to a configuration of the oscillation amplification unit; and a level detecting unit that detects an input voltage of the oscillation amplification unit, and, when the detected input voltage is higher than a bias voltage level at a time of oscillation, cause the switch unit to allow a current from the current sources to bypass through the replica circuit.
    Type: Grant
    Filed: January 27, 2010
    Date of Patent: October 25, 2011
    Assignee: Oki Semiconductor Co., Ltd.
    Inventor: Kenji Arai
  • 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
  • Patent number: 8031026
    Abstract: An apparatus for generating an oscillating signal including an oscillator configured to generate the oscillating signal, a controller configured to generate a control signal that controls a characteristic (e.g., amplitude or frequency) of the oscillating signal, and a power supply configured to supply power to the oscillator as a function of the control signal. The power supply may be configured to supply power to the oscillator as a function of the amplitude or frequency of the oscillating signal to improve power efficiency.
    Type: Grant
    Filed: May 29, 2009
    Date of Patent: October 4, 2011
    Assignee: QUALCOMM Incorporated
    Inventor: Jorge A. Garcia
  • Patent number: 7948329
    Abstract: A gain circuit of an oscillator circuit includes an inverter portion having an input IN and an output OUT arranged for connection to an external feedback circuit comprising a pi network. A feedback member having a first resistive element is coupled between the input IN and output OUT. An offset sense and correction block (OSCB) is configured to detect a dc offset potential difference between said input IN and output OUT and to reduce the offset potential by supplying a current to said input IN.
    Type: Grant
    Filed: May 6, 2008
    Date of Patent: May 24, 2011
    Assignee: Chartered Semiconductor Manufacturing, Ltd.
    Inventor: Hong Sair Lim
  • 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
  • Patent number: 7859351
    Abstract: An oscillation driver circuit includes a current-voltage converter which converts a current value of an oscillation signal in an oscillation loop into a voltage value, and a comparator which outputs a signal corresponding to the result of comparison between the output signal from the current-voltage converter and a given reference signal. The comparator has an output current limiting function. The oscillation driver circuit causes the vibrator to produce driving vibrations based on the output from the comparator.
    Type: Grant
    Filed: September 7, 2007
    Date of Patent: December 28, 2010
    Assignee: Seiko Epson Corporation
    Inventors: Masahiro Kanai, Eitaro Otsuka, Naoki Yoshida, Akihiro Fukuzawa
  • Patent number: 7859353
    Abstract: An oscillator, a driving circuit and an oscillation method are provided. The driving circuit and a crystal are coupled in parallel to generate a clock signal. The driving circuit includes a buffer unit and a control unit. The buffer unit is coupled in parallel to the crystal, and used to amplify an oscillation signal outputted from the crystal to generate the clock signal. The control unit is coupled to the buffer unit, and used to generate a control signal to the buffer unit. The control unit determines a voltage level of the control signal by detecting whether the clock signal or the oscillation signal satisfies an oscillation condition of the crystal, so as to control a gain value of the buffer unit. Therefore, noise of different frequency bands loaded into the clock signal can be avoided.
    Type: Grant
    Filed: November 13, 2008
    Date of Patent: December 28, 2010
    Assignee: Phison Electronics Corp.
    Inventors: Yu-Chia Liu, Yu-Tong Lin
  • Patent number: 7859352
    Abstract: Systems and methods for insuring successful initiation of a resonating micro-electro mechanical systems (MEMS). An example system includes a resonating sensor, a drive device, a charge amplifier, and a voltage gain circuit. At start up, the charge amplifier and voltage gain circuit receives signals from the resonating sensor, compensates this signal for DC offsets, and generates a clock signal for the drive, thus placing the resonating sensor in a steady state operating mode. The circuit includes a plurality of gain switches that are toggled to produce a glitch in the signal associated with the received signal. The glitch overcomes the DC offset. A comparator generates the clock signal for the drive device if a signal associated with the received signal exceeds a reference signal.
    Type: Grant
    Filed: October 15, 2008
    Date of Patent: December 28, 2010
    Assignee: Honeywell International Inc.
    Inventor: Michael Sutton
  • 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: 7852164
    Abstract: A piezoelectric oscillator includes: a piezoelectric resonator; an oscillation circuit including a variable resistance circuit and a transistor for oscillation; a constant current circuit, the constant current circuit including a first current mirror circuit, and a current control circuit having an output terminal and controlling a current flowing in the first current circuit so as to enable an output current of the constant current circuit to be adjusted, the output terminal of the first current mirror circuit being coupled to at least one of a collector and a base of the transistor for oscillation with the variable resistance circuit; and a control circuit coupled to the current control circuit and the variable resistance circuit, the control circuit controlling the current control circuit and a resistance value of the variable resistance circuit.
    Type: Grant
    Filed: November 11, 2008
    Date of Patent: December 14, 2010
    Assignee: Epson Toyocom Corporation
    Inventor: Masayuki Ishikawa
  • Publication number: 20100271147
    Abstract: The invention relates to a switched low-energy consumption amplifier for a piezoelectric element, which comprises: (a) an inductor, which together with the capacitance of said piezoelectric element forms an LC circuit; (b) a battery connected to said LC circuit; (c) a set of controlled switches capable of connecting and disconnecting circuit components at a rate which is significantly higher than the frequency of an input signal to said circuit; (d) a comparator for receiving an input signal, comparing a present voltage value of the input signal with a present voltage value over said piezoelectric element or a part, thereof, and conveying an indication regarding said comparison to a switching control unit; and (e) a switching control unit for receiving said indication from said comparator, and determining repeatedly every period P, which is significantly shorter than the period of the highest frequency included within said input signal, whether the piezoelectric element should be charged or discharged, and ac
    Type: Application
    Filed: November 20, 2008
    Publication date: October 28, 2010
    Applicant: AUDIODENT ISRAEL, LTD.
    Inventor: Vadim Leibman
  • Patent number: 7812681
    Abstract: An oscillation driver circuit includes a gain control amplifier which causes a vibrator to produce driving vibrations by controlling an oscillation amplitude in an oscillation loop, and a comparator which generates a synchronous detection reference signal based on a signal in the oscillation loop. The comparator has an output current limiting function. The oscillation driver circuit causes the vibrator to produce vibrations using an output from the comparator in a state in which the gain in an oscillation loop formed by the vibrator and the comparator is set to be larger than unity, and then causes the vibrator to produce the driving vibrations by controlling an oscillation amplitude in an oscillation loop formed by the vibrator and the gain control amplifier.
    Type: Grant
    Filed: October 12, 2007
    Date of Patent: October 12, 2010
    Assignee: Seiko) Epson Corporation
    Inventors: Masahiro Kanai, Eitaro Otsuka, Naoki Yoshida, Akihiro Fukuzawa
  • Patent number: 7812682
    Abstract: A crystal oscillator-based module, which includes a crystal resonator receiving a conditioned signal from a first bus and passing a resonator signal to a sustaining stage amplifier. A synchronization range expansion circuit is connected between a gain control network and the resonator. A tri-state buffer has a main input connected to receive the resonator signal through a buffer. The output of the tri-state buffer is connected to a second bus, through a matching network if necessary. A synchronous clock system can be formed by connecting these modules alternately to the two busses. The tri-state buffer also has a control input, which may be connected to a delay circuit between Vcc and ground, so as to allow hot swapping and for other benefits.
    Type: Grant
    Filed: March 5, 2009
    Date of Patent: October 12, 2010
    Assignee: NEL Frequency Controls, Inc.
    Inventors: Roman Boroditsky, Jorge Gomez
  • Publication number: 20100188157
    Abstract: This invention makes it possible to reduce a power consumption of an electronic circuit (microcomputer, for example) while preventing malfunctioning of an oscillator by appropriately setting a power supply impedance of a low frequency oscillator corresponding to an operation mode. A high frequency oscillator, a medium frequency oscillator and a low frequency oscillator are provided as sources of system clocks. In addition, there is provided a quartz oscillator to generate a clock for a timepiece. When the high frequency oscillator is in operation, a power supply impedance of the quartz oscillator is reduced to improve a noise tolerance. In a waiting period during which the high frequency oscillator, the medium frequency oscillator and the low frequency oscillator are halted, on the other hand, the power supply impedance of the quartz oscillator is increased to suppress the power consumption.
    Type: Application
    Filed: January 27, 2010
    Publication date: July 29, 2010
    Applicants: SANYO Electric Co., Ltd., SANYO Semiconductor Co., Ltd.
    Inventor: Hideo KONDO
  • Patent number: 7764135
    Abstract: A circuit arrangement and method utilize a variable threshold, multi-stage pulse shaping circuit to pulse shape a signal output by a crystal oscillator circuit. Each stage of the pulse shaping circuit includes a Schmitt trigger that drives an input of a latch, and that has a programmable trip point controlled to reject distorted pulses generated by the crystal oscillator circuit. A variable threshold, multi-stage pulse shaping circuit may be used, for example, to generate a clock signal for an electronic circuit that is more resistant to noise and other environmental effects, thereby reducing the likelihood of clock-related errors in the electronic circuit.
    Type: Grant
    Filed: March 8, 2007
    Date of Patent: July 27, 2010
    Assignee: NXP B.V.
    Inventor: Kevin Mahooti
  • 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
  • Publication number: 20100066458
    Abstract: An oscillator, a driving circuit and an oscillation method are provided. The driving circuit and a crystal are coupled in parallel to generate a clock signal. The driving circuit includes a buffer unit and a control unit. The buffer unit is coupled in parallel to the crystal, and used to amplify an oscillation signal outputted from the crystal to generate the clock signal. The control unit is coupled to the buffer unit, and used to generate a control signal to the buffer unit. The control unit determines a voltage level of the control signal by detecting whether the clock signal or the oscillation signal satisfies an oscillation condition of the crystal, so as to control a gain value of the buffer unit. Therefore, noise of different frequency bands loaded into the clock signal can be avoided.
    Type: Application
    Filed: November 13, 2008
    Publication date: March 18, 2010
    Applicant: PHISON ELECTRONICS CORP.
    Inventors: Yu-Chia Liu, Yu-Tong Lin
  • Patent number: 7649426
    Abstract: An oscillator includes an oscillator circuit and a resonator that produces an output frequency. A temperature compensation circuit is coupled to the oscillator circuit. The temperature compensation circuit stabilizes the output frequency in response to changes in temperature. At least one temperature sensor and a temperature sensor signal modification circuit are coupled to the temperature compensation circuit. The temperature sensor signal modification circuit receives a temperature signal from the temperature sensor and generates a modified temperature sensor signal that is transmitted to the temperature compensation circuit.
    Type: Grant
    Filed: September 4, 2007
    Date of Patent: January 19, 2010
    Assignee: CTS Corporation
    Inventor: James L. Stolpman
  • 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: 7573346
    Abstract: An oscillation circuit includes a constant current source, a current mirror circuit configured to receive a constant input current from the constant current source and to output a current proportional to the constant input current, a first inverter configured to be driven with a quartz resonator to oscillate, an operational amplifier configured to supply a power to the first inverter with a voltage equal to an input voltage thereof and a second inverter having a power supply terminal connected to the current mirror circuit and to the operational amplifier and configure to generate the input voltage for the operational amplifier.
    Type: Grant
    Filed: August 21, 2007
    Date of Patent: August 11, 2009
    Assignee: Ricoh Company, Ltd.
    Inventor: Kohichi Hagino
  • Patent number: 7564317
    Abstract: A high/low voltage tolerant interface circuit and a crystal oscillator circuit using the same are provided herein. The interface circuit includes a first transistor, a bulk-voltage generator module and an bias module. The first transistor includes a gate, a first source/drain, a bulk coupled to the first source/drain of the first transistor and a second source/drain coupled to an input node. The bulk-voltage generator module is, used to determine whether a first voltage or a predetermined voltage is being provided to the bulk of the first transistor according to the voltage of the input node. The bias module is coupled to the gate of the first transistor. The bias module is used to provide an bias voltage to the gate of the first transistor and makes the first transistor conduct in order to control the voltage of the second source/drain voltage of the first transistor.
    Type: Grant
    Filed: July 6, 2007
    Date of Patent: July 21, 2009
    Assignee: Amazing Microelectronic Corporation
    Inventors: Ming-Dou Ker, Hung-Tai Liao, Ryan Hsin-Chin Jiang
  • Publication number: 20090079510
    Abstract: A Global positioning system and integrated circuit, and a method for starting an associated quartz oscillator with an oscillator circuit that has terminals for a quartz crystal in order to generate a reference signal, and with a status circuit connected to the oscillator circuit, wherein the status circuit has first means for producing a constant operating current of an operating state and a constant starting current of a starting state for the oscillator circuit, the status circuit has second means for producing a quantity dependent on the amplitude of the reference signal, the status circuit has a comparator for comparing the quantity to a switch-on threshold value, and the status circuit has a current switch that is connected to the comparator in such a manner that when the switch-on threshold is exceeded by the quantity, the current switch switches from the starting current to the operating current.
    Type: Application
    Filed: September 5, 2007
    Publication date: March 26, 2009
    Inventor: Meik Wilhelm Widmer
  • Publication number: 20090039972
    Abstract: A circuit arrangement and method utilize a variable threshold, multi-stage pulse shaping circuit to pulse shape a signal output by a crystal oscillator circuit. Each stage of the pulse shaping circuit includes a Schmitt trigger that drives an input of a latch, and that has a programmable trip point controlled to reject distorted pulses generated by the crystal oscillator circuit. A variable threshold, multi-stage pulse shaping circuit may be used, for example, to generate a clock signal for an electronic circuit that is more resistant to noise and other environmental effects, thereby reducing the likelihood of clock-related errors in the electronic circuit.
    Type: Application
    Filed: March 8, 2007
    Publication date: February 12, 2009
    Applicant: NXP B.V.
    Inventor: Kevin Mahooti
  • 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: 20080211593
    Abstract: Provided is an oscillation circuit capable of obtaining a plurality of oscillation frequencies using a single oscillation resonator. The oscillation circuit includes the oscillation resonator, an oscillation inverter, a dumping resister connected between an output of the oscillation inverter and an output terminal, a feedback resistor connected with input and output of the oscillation inverter, and a feedback resistor switch for varying a feedback resistance value or an oscillation inverter switch for varying a mutual conductance value of the oscillation inverter. When the feedback resistance value or the mutual conductance value of the oscillation inverter is varied by the feedback resistor switch or the oscillation inverter switch, a frequency band of the oscillation circuit is adjusted to select a harmonic component of the oscillation resonator. Therefore, an oscillation frequency can be switched, so it is possible to obtain a plurality of oscillation frequencies using a single oscillation resonator.
    Type: Application
    Filed: February 15, 2008
    Publication date: September 4, 2008
    Inventors: Yutaka Sato, Kotaro Watanabe