Class / Patent application number | Description | Number of patent applications / Date published |
331036000 | Reactance device (e.g., variable capacitors, saturable inductors, reactance tubes, etc.) | 57 |
20100026406 | Phase-locked loop circuit, recording-and-reproducing apparatus, and electronic appratus - A phase-locked loop circuit includes a phase detection unit, a loop filter unit including a series circuit of a resistor and a capacitor, first and second pulse-current output units which supply differential and single-end pulse currents corresponding to phase information to the resistor and capacitor, an oscillating unit which varies an oscillation frequency in accordance with a voltage generated at the resistor and capacitor, and a calibration unit which obtains information of an oscillation gain in actual operation and corrects an operation of the oscillating unit on the basis of a difference between the oscillation gain in actual operation and a target oscillation gain. The oscillation gain in actual operation represents a characteristic of oscillation frequency versus input signal of the oscillating unit and is obtained using predetermined oscillation control signals on the basis of a difference between actual oscillation frequencies under the oscillation control signals. | 02-04-2010 |
20100052803 | VOLTAGE CONTROLLED OSCILLATOR - An integrated circuit and an apparatus are provided. The integrated circuit comprises a bias circuit, an LC resonator circuit, and a current mode logic (CML) frequency divider. The bias circuit generates first and second bias voltages. The LC resonator circuit generates an oscillation signal having an oscillation frequency. The CML frequency divider, coupled to the bias circuit and the LC resonator circuit, biased by the first and second bias voltages, receives the oscillation signal to generate an output signal having an output frequency with a fractional rate of the oscillation frequency. The oscillation signal comprises AC and DC components, the CML frequency divider receives the AC component to determine an injected frequency and reuses the DC component to provide tail currents to determine a natural frequency of the CML frequency divider. The output frequency is determined by the injected frequency and the natural frequency. | 03-04-2010 |
20110267150 | Automatic Frequency Control Architecture with Digital Temperature Compensation - A mixed signal circuit architecture is disclosed for automatic frequency control and digital temperature compensation in an LC-PLL system. Some embodiments allow for high-volume manufacturing of products such as microprocessors and chipsets, and other circuits that employ LC-PLL technology. In some embodiments, various capacitor loadings can be selected to compensate for variation associated with process, voltage, temperature, and reference frequency. In addition, a multi-leg capacitor bank can be selectively used to further compensate for temperature variation post-lock, in accordance with some embodiments. A programmable timer can be used in some embodiments to allow for loop settling prior to assessing parameters of interest. | 11-03-2011 |
20130278347 | COMPENSATION FOR DIGITALLY CONTROLLED OSCILLATOR APPARATUS AND METHOD - Automatic digital sensing and compensation of frequency drift caused by temperature, aging, and/or other effects may be provided by including a compensation capacitor array and a sensing logic. The sensing logic may be configured to detect a drift in a first control signal and to provide the compensation capacitor array with a second control signal. The second control signal is configured to cause an adjustment of capacitance in the compensation capacitor array based on the detected drift in the first control signal. | 10-24-2013 |
20130328638 | VOLTAGE-CONTROLLED-OSCILLATOR (VCO) ARCHITECTURE FOR REDUCING DISTURBANCE - Operations of a signal generator, which may be configurable to generate signals at one or more particular frequencies, may be controlled. The controlling may occur by setting frequency of an output of the signal generator by setting one or both of impedance and capacitance associated with the signal generator; and tuning the signal generator by applying one or more adjustments to the impedance and the capacitance associated with the signal generator, to maintain the set frequency. The signal generator may comprise a phase-locked loop (PLL), comprising a voltage controlled oscillator (VCO) for use in generating oscillating signals driving the generation of the PLL output. The VCO may be configurable to generate signals at varying frequencies, and may comprise at least one impedance element, at least one variable capacitance element and a plurality of tuning branches, where each tuning branch comprises at least a static capacitance element and a switching element. | 12-12-2013 |
20140002206 | CIRCUIT REDUCING PHASE NOISE OF OSCILLATOR | 01-02-2014 |
20150061787 | METHOD AND APPARATUS FOR SUPPRESSING A DETERMINISTIC CLOCK JITTER - A method for generating an output clock comprising: detecting a timing difference between a first input clock and a second input clock to generate a phase error signal; generating a masked phase error signal by masking the phase error signal based on a deterministic jitter indicator signal; generating an oscillator control signal by filtering the masked phase error signal; and generating the output clock in accordance with the oscillator control signal. | 03-05-2015 |
20080238566 | High frequency oscillator circuit with feedback circuit of fet and short-stub transmission line - In a high frequency oscillator circuit including first and second field effect transistors, the first field effect transistor has a gate connected to a short-stub transmission line and a drain connected to an oscillation output terminal, and the second field effect transistor has a drain connected to a source of the first field effect transistor and a grounded source. The high frequency oscillator circuit oscillates by using a feedback circuit including the short-stub transmission line and the second field effect transistor. A feedback capacitor is further provided which is connected between a gate of the second field effect transistor and the drain of the first field effect transistor. | 10-02-2008 |
20080303603 | SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE - A semiconductor integrated circuit device includes a voltage controlled oscillator which controls a bias current or an oscillation frequency to supply an output signal, a phase-locked loop circuit which supplies a frequency control signal based on the output signal supplied from the voltage controlled oscillator, a peak detection circuit which detects a peak of the frequency control signal supplied from the phase-locked loop circuit, and a bias control circuit which produces a bias current based on the peak detected by the peak detection circuit to supply the bias current. The voltage controlled oscillator controls the bias current supplied from the bias control circuit or the oscillation frequency to supply the output signal based on the frequency control signal supplied from the phase-locked loop circuit. | 12-11-2008 |
20090002088 | DIGITAL CONTROLLED OSCILLATOR, FREQUENCY SYNTHESIZER, RADIO COMMUNICATION APPARATUS USING THE SAME, AND CONTROL METHOD FOR THE SAME - The digital controlled oscillator includes a variable capacitance section having a first capacitor array of a plurality of first variable capacitors and a second capacitor array of a plurality of second variable capacitors, and generates a signal having an oscillation frequency corresponding to the capacitance value of the variable capacitance section. The first capacitance change amount in the individual first variable capacitors is a value obtained by multiplying the second capacitance change amount in the individual second variable capacitors by an integer equal to or more than 2, and the number of second variable capacitors is equal to or more than a value obtained by subtracting 1 from the integer equal to or more than 2. | 01-01-2009 |
20090033433 | Circuits, Systems, and Methods for a Voltage Controlled Oscillator with Coarse, Fine, and Center Tuning - Circuits, systems, and methods for generating a variable oscillator output. The circuits generally comprise a capacitor configured to receive first and second currents of a first polarity (e.g., charging currents) and a third current of a second polarity opposite to the first polarity (e.g., a discharge current). The circuit further comprises a first circuit configured to receive a bias input, a second circuit configured to receive a coarse control input, and a third circuit configured to receive a fine control input. The first circuit is further configured to provide the first current in response to the bias input. The second circuit is further configured to provide the second current in response to the coarse control input, such that the second current generally has a magnitude of from zero to a multiple of the magnitude of the first current. The third circuit is further configured to provide the third current when the capacitor has a voltage that passes a threshold voltage determined by the fine control input. The present invention advantageously provides for producing a variable oscillator output over a broad range with the coarse control input, while also having low gain with the fine control input. The present invention is also advantageously suitable for standard integrated circuit manufacturing processes because the bias input can be adjusted to compensate for process variations. | 02-05-2009 |
20090033434 | OSCILLATION CIRCUIT - A first switch (SW | 02-05-2009 |
20090039973 | VCO driving circuit and frequency synthesizer - A VCO driving circuit and a frequency synthesizer wherein the impedance viewed from a VCO control terminal is reduced to prevent the VCO phase noise characteristic from degrading. A VCO driving circuit and a frequency synthesizer having the VCO driving circuit, which comprises a coarse adjustment DAC that receives a digital data, which has a coarse adjustment frequency, to output an analog signal; a fine adjustment DAC that receives a digital data, which has a fine adjustment frequency, to output an analog signal; a low response speed LPF | 02-12-2009 |
20090261917 | AUXILIARY VARACTOR FOR TEMPERATURE COMPENSATION - Techniques for compensating for the effects of temperature change on voltage controlled oscillator (VCO) frequency are disclosed. In an embodiment, an auxiliary varactor is coupled to an LC tank of the VCO. The auxiliary varactor has a capacitance controlled by a temperature-dependant control voltage to minimize the overall change in VCO frequency with temperature. Techniques for generating the control voltage using digital and analog means are further disclosed. | 10-22-2009 |
20090278620 | VCO CAPACITOR BANK TRIMMING AND CALIBRATION - Techniques are disclosed for trimming a capacitance associated with a capacitor bank for use in a voltage-controlled oscillator (VCO). In an embodiment, each capacitance is sub-divided into a plurality of constituent capacitances. The constituent capacitances may be selectively enabled or disabled to trim the step sizes of the capacitor bank. Further techniques are disclosed for calibrating the trimmable capacitance to minimize step size error for the capacitor bank. | 11-12-2009 |
20100007428 | OSCILLATION CIRCUIT - This oscillation circuit includes a triangular wave generation circuit that generates a triangular wave signal corresponding to an outputted clock signal, a comparison circuit that generates a clock signal corresponding to a comparison of the triangular wave signal with a first reference voltage and a second reference voltage, a current adjusting circuit that adjusts the value of adjusted current according to the power supply voltage for the comparison circuit, and a reference voltage generation circuit that generates the first reference voltage and the second reference voltage having a voltage differential that corresponds to the value of the adjusted current. The current adjusting circuit increases the adjusted current when the power supply voltage for the comparison circuit rises, and reduces the adjusted current when the power supply voltage drops. The reference voltage generation circuit increases the voltage differential between the first reference voltage and the second reference voltage when the adjusted current increases, and reduces the voltage differential when the adjusted current decreases. | 01-14-2010 |
20100026405 | Phase-locked loop circuit, recording-and-reproducing apparatus, and electronic apparatus - A phase-locked loop circuit includes a phase detection unit which detects phase information of an input signal, a loop filter unit including a series circuit of a resistor and a capacitor, first and second pulse-current output units which supply pulse currents corresponding to the phase information output to one and the other of the resistor and the capacitor, and an oscillating unit capable of varying an oscillation frequency in accordance with a component obtained by combining a voltage generated at both ends of the one of the resistor and the capacitor on the basis of the pulse current supplied from the output terminal of the first pulse-current output unit and a voltage generated at both ends of the other one of the resistor and the capacitor on the basis of the pulse current supplied from the output terminal of the second pulse-current output unit. | 02-04-2010 |
20100033260 | OSCILLATION CIRCUIT - An oscillation circuit according to an exemplary embodiment of the present invention includes: a power supply voltage terminal applied with a power supply voltage; a feedback loop circuit that outputs an oscillation frequency signal; and a correction circuit that corrects a time constant of the feedback loop circuit in accordance with the power supply voltage applied to the power supply voltage terminal. The configuration facilitates the correction of an oscillation frequency that varies depending on the fluctuation of the power supply voltage. | 02-11-2010 |
20100073101 | Low-noise voltage controlled oscillator - A low-noise voltage controlled oscillator is provided, to improve a phase noise characteristic and widen a frequency variable range. The low-noise voltage controlled oscillator is configured so that an oscillation element and a capacitor | 03-25-2010 |
20100123525 | Clock Control for Data Synchronization in Varactor Arrays - Implementations of varactor systems compare current data with immediately prior data to determine whether there has been a change in the data, and enable a clock signal for data paths which have changed data. | 05-20-2010 |
20100148881 | Digital Calibration Techniques for Segmented Capacitor Arrays - An apparatus includes phase detection circuitry that generates control signals in response to an input clock signal and a feedback clock signal. The apparatus also includes a clock signal generation circuit that includes fine and coarse capacitors. The clock signal generation circuit changes a capacitance of the capacitors that are affecting the output clock signal in response to a change in the control signals. The apparatus also includes measurement circuitry that determines a calibration number of the fine capacitors having a combined capacitance that most closely matches a capacitance of one of the coarse capacitors. | 06-17-2010 |
20100156550 | ADJUSTABLE CAPACITOR, DIGITALLY CONTROLLED OSCILLATOR, AND ALL-DIGITAL PHASE LOCKED LOOP - An adjustable capacitor is provided including a capacitor unit including a plurality of capacitor groups aligned in a matrix format and a switch unit to adjust capacitance by connecting the plurality of capacitor groups in parallel according to a selection signal of a column and row of the matrix. Accordingly, the adjustable capacitor may be realized of a small size but with a high capacitance change rate. | 06-24-2010 |
20100265001 | DIGITAL PLL CIRCUIT AND SEMICONDUCTOR INTEGRATED CIRCUIT - A digital PLL circuit includes: an oscillation circuit, wherein an oscillation frequency is controlled by changing the number of capacitance elements to be connected in parallel to an inductance element; and a phase comparator part configured to perform a digital phase comparison of a reference clock and a delayed clock thereof, with an oscillation circuit output; and based on the comparison result, to control the number of the capacitance elements so as to bring the phase of the oscillation circuit output closer to the reference clock phase, wherein the capacitance element includes: a coarse adjustment capacitor configured to have a predetermined capacitance; and fine adjustment capacitors configured to have a capacitance of 1/n of that of the coarse adjustment capacitor, wherein a predetermined number of the fine adjustment capacitors function as one coarse adjustment capacitor at the time of coarse adjustment. | 10-21-2010 |
20110080228 | Voltage controlled oscillator - To provide a voltage controlled oscillator capable of being treated as a lumped constant circuit, having small size and capable of obtaining an oscillation frequency in a high frequency band. A resonance part | 04-07-2011 |
20110121910 | PHASE LOCKED LOOP APPARATUS WITH SELECTABLE CAPACITANCE DEVICE - A phase locked loop apparatus includes an oscillator, a variable capacitance device, a selectable capacitance device, and a capacitance controller that is configured to provide a control signal to the selectable capacitance device. The selectable capacitance device is connected to the oscillator and is responsive to the control signal such that the selectable capacitance device has a first capacitance at a first control signal value and a second capacitance at a second control signal value. The capacitance controller only selects either the first capacitance or the second capacitance by providing a control signal that has the first control signal value to select the first capacitance and having the second control signal value to select the second capacitance. | 05-26-2011 |
20110221539 | OSCILLATOR WITH CONTROLLABLE FREQUENCY - Apparatuses are disclosed which comprise a coarse tuning circuitry, a fine tuning circuitry and at least one switchable capacitance. | 09-15-2011 |
20110234331 | INTEGRATED CIRCUITS WITH CONFIGURABLE INDUCTORS - Integrated circuits with phase-locked loops are provided. Phase-locked loops may include an oscillator, a phase-frequency detector, a charge pump, a loop filter, a voltage-controlled oscillator, and a programmable divider. The voltage-controlled oscillator may include multiple inductors, an oscillator circuit, and a buffer circuit. A selected one of the multiple inductors may be actively connected to the oscillator circuit. The voltage-controlled oscillators may have multiple oscillator circuits. Each oscillator circuit may be connected to a respective inductor, may include a varactor, and may be powered by a respective voltage regulator. Each oscillator circuit may be coupled to a respective input transistor pair in the buffer circuit through associated coupling capacitors. A selected one of the oscillator circuits may be turned on during normal operation by supplying a high voltage to the selected one of the oscillator circuit and by supply a ground voltage to the remaining oscillator circuits. | 09-29-2011 |
20120007686 | MULTIBAND VOLTAGE CONTROLLED OSCILLATOR WITHOUT SWITCHED CAPACITOR - A controlled oscillator includes, connected in parallel, a capacitor configured to be tuneable based upon a first signal, an inductor, and an active impedance. The active impedance is formed by a pair of cross-coupled transistors connected so as to produce a negative resistive component at the terminals of the active impedance. Circuitry produces a degeneracy tuneable by a second signal in the cross-coupled pair, such that the cross-coupled pair produces a capacitive component tuneable based upon the second signal at the terminals of the active impedance. | 01-12-2012 |
20120068780 | Systems and Methods for Reducing Frequency Pulling in an Oscillator Circuit - Methods and systems are provided to calibrate an oscillator circuit to reduce frequency pulling as a result of a change in power to a portion of the oscillator circuit. In an embodiment, an oscillator is coupled to a clock buffer circuit and a tuning capacitor configured to tune a frequency of the oscillator to a baseline frequency required for cellular communications. A change in power to the clock buffer circuit initiates a change in an amount of capacitance seen by the oscillator, which negatively impacts the tuning of the oscillator. A register stores a frequency offset caused by the change in power, and the tuning capacitor is adjusted, using the frequency offset, in response to the change in power, such that the total amount of capacitance seen by the oscillator is not changed when the change in power occurs. | 03-22-2012 |
20120119839 | PLL FREQUENCY SYNTHESIZER - Disclosed is a PLL frequency synthesizer the phase noise characteristics of which are improved. To achieve this, in an ADPLL frequency synthesizer ( | 05-17-2012 |
20120139654 | FREQUENCY SYNTHESIZER - A frequency synthesizer includes a control circuit configured to generate a digital control signal; and a digitally controlled oscillator of which oscillation frequency changes according to the generated digital control signal. The control circuit includes an operational circuit configured to divide an integer portion of a numerical value representing a phase difference between a reference signal and an oscillation frequency signal of the digitally controlled oscillator into high-order bits and low-order bits including a redundant bit as an MSB, and two encoders configured to encode the high-order bits and the low-order bits to generate control signals. The digitally controlled oscillator includes two capacitive element groups having capacitance values controlled by the control signals. The oscillation frequency of the digitally controlled oscillator changes according to a total capacitance value of the two capacitive element groups. | 06-07-2012 |
20120194286 | METHODS AND SYSTEMS FOR MEMS CMOS DEVICES HAVING ARRAYS OF ELEMENTS - Systems and methods for manufacturing a chip comprising a plurality of MEMS devices arranged in an integrated circuit are provided. In one aspect, the systems and methods provide for a chip including electronic elements formed on a semiconductor material substrate. The chip further includes a stack of interconnection layers including layers of conductor material separated by layers of dielectric material. MEMS devices are formed within the stack of interconnection layers by applying gaseous HF to a first layer of dielectric material positioned highest in the stack of interconnection layers. The stack of interconnection layers includes at least one unetched layer of dielectric material, and at least one layer of conductor material for routing connections to and from the electronic elements. | 08-02-2012 |
20120326797 | VCO UTILIZING AN AUXILIARY VARACTOR WITH TEMPERATURE DEPENDENT BIAS - A technique to use an auxiliary varactor coupled to a tuning varactor, in which a temperature compensated bias signal adjusts a bias on the auxiliary varactor to maintain a voltage controlled oscillator (VCO) from drifting in frequency as operating temperature for the VCO changes. | 12-27-2012 |
20130127555 | Systems and Methods for Reducing Frequency Pulling in an Oscillator Circuit - Methods and systems are provided to calibrate an oscillator circuit to reduce frequency pulling as a result of a change in power to a portion of the oscillator circuit. In an embodiment, an oscillator is coupled to a clock buffer circuit and a tuning capacitor configured to tune a frequency of the oscillator to a baseline frequency required for cellular communications. A change in power to the clock buffer circuit initiates a change in an amount of capacitance seen by the oscillator, which negatively impacts the tuning of the oscillator. A register stores a frequency offset caused by the change in power, and the tuning capacitor is adjusted, using the frequency offset, in response to the change in power, such that the total amount of capacitance seen by the oscillator is not changed when the change in power occurs. | 05-23-2013 |
20130154754 | TUNING OF MEMS OSCILLATOR - A method is provided for tuning a microelectromechanical systems (MEMS) oscillator comprising an acoustic resonator and a tuning and amplification circuit arranged in a loop. The method comprises determining an initial oscillation frequency of the oscillator, modifying a capacitance of the tuning and amplification circuit according to the initial oscillation frequency, and adjusting a power level of the oscillator according to the modified capacitance. | 06-20-2013 |
20130176082 | REFERENCE VOLTAGE GENERATION CIRCUIT, OSCILLATION CIRCUIT INCLUDING THE SAME AND METHOD FOR CALIBRATING OSCILLATION FREQUENCY OF OSCILLATION CIRCUIT - A reference voltage generation circuit has: a first PN junction element; a second PN junction element having a higher forward direction voltage than the first PN junction element; a first differential amplifier inputting an anode of the first PN junction element and a first connection node between a first and a second resistor disposed in series between a first output of the first differential amplifier and a first potential, and generating a first output voltage at the first output; and a second differential amplifier inputting an anode of the second PN junction element and a second connection node between a fourth and a third resistor disposed in series between a second output of the second differential amplifier and the first output of the first differential amplifier, and generating a reference voltage at the second output. A resistance ratio between the third and the fourth resistors is variable. | 07-11-2013 |
20130194050 | VOLTAGE CONTROLLED OSCILLATOR USING VARIABLE CAPACITOR AND PHASE LOCKED LOOP USING THE SAME - A variable capacitor is provided. The variable capacitor includes a plurality of capacitor segments. The plurality of capacitor segments are connected in parallel within the variable capacitor. When a plurality of candidate capacitances allowable to the variable capacitor according to a connection state of the plurality of capacitor segments connected in parallel are sorted in a magnitude sequence, the plurality of candidate capacitances form a geometric series. The variable capacitor is used for a Voltage Controlled Oscillator (VCO), and the VCO is used for a Phase Locked Loop (PLL). | 08-01-2013 |
20130234802 | METHOD AND APPARATUS FOR DRIFT COMPENSATION IN PLL - Aspects of the disclosure provide a phase-locked loop (PLL). The PLL includes a voltage-controlled oscillator (VCO), a detector module, and a ramp module. The VCO has a first capacitor unit and a second capacitor unit. The VCO is configured to generate an oscillating signal having a frequency based on a first capacitance of the first capacitor unit and a second capacitance of the second capacitor unit. The detector module is configured to generate a voltage signal as a function of the oscillating signal and a reference signal. The voltage signal is used to control the first capacitor unit to stabilize the frequency of the oscillating signal. The ramp module is configured to generate a ramp signal based on the voltage signal. The ramp signal is used to control the second capacitor unit to ramp the second capacitance from a first value to a second value. | 09-12-2013 |
20130257556 | SIGNAL PROCESSING APPARATUS, SIGNAL PROCESSING METHOD AND COMMUNICATION APPARATUS - Disclosed herein is a signal processing apparatus including: a voltage-controlled oscillation block having a parameter high in correlation with a filter; a measuring block configured to measure an oscillation frequency of the voltage-controlled oscillation block; and a control block configured to control the parameter of the filter by use of a measuring result of the oscillation frequency obtained by the measuring block. | 10-03-2013 |
20140002205 | FREQUENCY SYNTHESIZER APPARATUS AND METHODS FOR IMPROVING CAPACITOR CODE SEARCH ACCURACY USING LSB MODULATION | 01-02-2014 |
20140035691 | CAPACITIVE DIVIDER STRUCTURE - A capacitive divider structure, comprising: a first plurality of capacitive devices, each being selectively controlled in accordance with a first input control signal so as to alter the effective capacitance of the capacitive divider structure by a first amount; a second plurality of capacitive devices coupled in parallel with the first plurality of capacitive devices, each being selectively controlled in accordance with a second input control signal so as to alter the effective capacitance of the capacitive divider structure by a second amount; and at least one series capacitive device arranged in series with the second plurality of capacitive devices, such that the second amount is less than the first amount. | 02-06-2014 |
20140091872 | OSCILLATOR CIRCUIT, VIBRATORY DEVICE, ELECTRONIC APPARATUS, MOVING OBJECT, METHOD OF ADJUSTING VIBRATORY DEVICE, AND SENSITIVITY ADJUSTMENT CIRCUIT - An oscillator circuit includes a terminal T1, a terminal T2, a variable capacitance element having one end connected to the terminal T1, and a capacitance value varying in accordance with a frequency control signal, a variable capacitance element having one end connected to the terminal T2, and a capacitance value varying in accordance with the frequency control signal, a load capacitance circuit connected to the terminal T1, and a load capacitance circuit connected to the terminal T2, and oscillates a resonator element at a frequency corresponding to the frequency control signal. The oscillator circuit is capable of adjusting the capacitance values of the load capacitance circuits, a reference voltage (the electrical potential of the terminal T1), and a reference voltage (the electrical potential of the terminal T2) in accordance with configuration information. | 04-03-2014 |
20140118080 | FREQUENCY SYNTHESIZER - A digitally controlled frequency synthesizer less influenced by disturbance noise is provided without using a ΔΣ modulator. The frequency synthesizer, whose oscillation frequency is digitally controlled, includes a loop gain control section configured to generate digital control data for controlling a loop gain of the frequency synthesizer; a DA conversion section configured to convert lower bits of the digital control data to an analog voltage; and an oscillation section configured to oscillate at a frequency corresponding to higher bits of the digital control data and the analog voltage output from the DA conversion section. | 05-01-2014 |
20140152394 | FREQUENCY DETECTION CIRCUITS, RADIO FREQUENCY SIGNAL PROCESSING DEVICES AND METHODS FOR CALIBRATING INDUCTANCE AND CAPACITANCE - A frequency detection circuit includes a filter, a power detector and a voltage comparator. The filter receives and filters a converted signal to generate a filtered signal. The power of the filtered signal relates to a frequency of the converted signal. The power detector generates a voltage according to the power of the filtered signal. The voltage comparator compares the voltage with multiple reference voltages to generate multiple comparison results. At least one of the inductance and capacitance of an LC tank in an amplifier is adjusted according to the comparison results. | 06-05-2014 |
20140184348 | CIRCUIT FOR ADJUSTING FREQUENCY OF CRYSTAL OSCILLATOR - A circuit for adjusting frequency of a crystal oscillator includes a basic input output system (BIOS), a platform controller hub (PCH), a buffer, and a capacitor module with a number of capacitors. The crystal oscillator is connected to clock pins of the PCH. An input pin of the buffer is connected to the crystal oscillator. A first end of the each of the capacitors is connected to an output pin of the buffer. A second end of the each of the capacitors is grounded. The buffer includes two enable pins and a control unit controlled by the enable pins. The enable pins of the buffer receive a control signal from the PCH according to the BIOS, and control the control unit to appoint the corresponding capacitor of the capacitor module to be connected to the input pin of the buffer. | 07-03-2014 |
20140218124 | APPARATUS AND METHOD FOR GENERATING AN OSCILLATING OUTPUT SIGNAL - An apparatus for generating an oscillating output signal includes an inductive-capacitive (LC) circuit and a current tuning circuit. The LC circuit includes a primary inductor and a varactor coupled to the primary inductor. A capacitance of the varactor is responsive to a voltage at a control input of the varactor. The current tuning circuit includes a secondary inductor and a current driving circuit coupled to the secondary inductor. The current driving circuit is responsive to a current at a control input of the current driving circuit. An effective inductance of the primary inductor is adjustable via magnetic coupling to the secondary inductor, and a frequency of the oscillating output signal is responsive to the effective inductance of the primary inductor and to the capacitance of the varactor. | 08-07-2014 |
20140253255 | VOLTAGE CONTROLLED OSCILLATOR BAND-SELECT FAST SEARCHING USING PREDICTIVE SEARCHING - A method, an apparatus, and a computer program product are provided. The apparatus tunes a frequency provided by a VCO. The apparatus determines a relative capacitance change associated with a first frequency and a desired frequency from a look-up table. The apparatus adjusts a capacitor circuit in the VCO based on the determined relative capacitance change determined from the look-up table in order to tune from the first frequency to the desired frequency. The apparatus determines that the frequency provided by the VCO is a second frequency different than the desired frequency after adjusting the capacitor circuit. The apparatus performs an iterative search to further adjust the capacitor circuit when a difference between the second frequency and the desired frequency is greater than a threshold. | 09-11-2014 |
20140253256 | MONOLITHIC CLOCK GENERATOR AND TIMING/FREQUENCY REFERENCE - A periodic signal generator includes a resonant LC tank circuit that generates a periodic reference signal at a first frequency at a differential output thereof. A temperature-responsive frequency compensation module is electrically coupled to the differential output of the resonant LC tank circuit. This module includes a temperature dependent voltage control module that generates a temperature dependent control voltage and an array of switchable capacitive modules that is electrically coupled to a first node of the differential output of the resonant LC tank circuit and responsive to the temperature dependent control voltage and a plurality of switching coefficients. The array of switchable capacitive modules includes a fixed capacitor having a first terminal electrically coupled to the first node and a voltage-controlled variable capacitor having a first terminal electrically coupled to the first node. | 09-11-2014 |
20140340164 | CR OSCILLATION CIRCUIT - In a CR oscillation circuit, resistance elements forming a series circuit include a first resistance element having a large temperature coefficient of resistance and a second resistance element having a smaller temperature coefficient of resistance than the first resistance element. At least one of a capacitor and an oscillation resistance element is trimmable. A first switching circuit connected between the series circuit and a non-inverting input terminal of a comparator is turned on when an output signal of the comparator is at a high level, and a second switching circuit is turned on when the output signal is at a low level. | 11-20-2014 |
20140361846 | COMMUNICATION DEVICE AND CONTROL METHOD THEREOF - A communication device is provided in the present invention. The communication device comprises an oscillation signal source, a tunable capacitor array, a frame counter; and a control module. The control module is configured to jointly or separately control the tunable capacitor array and the frame counter to compensate a first frequency offset of the oscillation signal source when the communication device operates in a first mode, and to jointly or separately control the tunable capacitor array and the frame counter to compensate a second frequency offset of the oscillation signal source when the communication device operates in a second mode. | 12-11-2014 |
20150015343 | DEVICES AND METHODS FOR REDUCING NOISE IN DIGITALLY CONTROLLED OSCILLATORS - One feature pertains to a digitally controlled oscillator (DCO) that comprises a variable capacitor and noise reduction circuitry. The variable capacitor has a variable capacitance value that controls an output frequency of the DCO. The variable capacitance value is based on a first bank capacitance value provided by a first capacitor bank, a second bank capacitance value provided by a second capacitor bank, and an auxiliary bank capacitance value provided by an auxiliary capacitor bank. The noise reduction circuitry is adapted to adjust the variable capacitance value by adjusting the auxiliary bank capacitance value while maintaining at least one of the first bank capacitance value and/or the second bank capacitance value substantially unchanged. Prior to adjusting the variable capacitance value, the noise reduction circuitry may determine that a received input DCO control word transitions across a capacitor bank sensitive boundary. | 01-15-2015 |
20150077193 | VOLTAGE-CONTROLLED OSCILLATOR, SIGNAL GENERATION APPARATUS, AND ELECTRONIC DEVICE - The present invention is for, in a voltage-controlled oscillator in which the oscillation frequency can be adjusted using a capacitor array, reducing drift that occurs in the carrier frequency if the oscillation signal is subjected to frequency modulation after the control loop of the PLL circuit has been cut off. This voltage-controlled oscillator includes an oscillation circuit for performing an oscillation operation at a frequency that corresponds to an inductance and a capacitance between a first node and a second node, a first and second group of capacitors that have first terminals connected to the first node and the second node respectively, a first and second group of transistors that are respectively connected between a reference potential and second terminals of the first group and second group of capacitors, and a first and second group of resistors that are respectively parallel-connected to the first group and second group of transistors. | 03-19-2015 |
20150084711 | OSCILLATION CIRCUIT, ELECTRONIC APPARATUS, MOVING OBJECT, AND METHOD FOR MANUFACTURING OSCILLATION CIRCUIT - An oscillation circuit includes an oscillation amplifier circuit that causes an oscillating element to oscillate to generate an oscillation signal, and a correction circuit connected with the oscillation amplifier circuit. At least a power supply voltage is input to the oscillation amplifier circuit. The oscillation amplifier circuit has a frequency variation characteristic that the frequency of the oscillation signal varies in response to variations in the power supply voltage. The power supply voltage is input to the correction circuit. The correction circuit corrects the frequency variation characteristic by using variations in the power supply voltage. The correction circuit may include a first variable capacitance element, and the first variable capacitance element may have a capacitance-voltage characteristic by which the frequency variation characteristic is reduced. | 03-26-2015 |
20150102867 | LC OSCILLATOR PROCESS COMPENSATION CIRCUIT - An LC oscillator process compensation circuit includes an LC oscillator, a reference voltage terminal, a follower and a current auxiliary circuit, the LC oscillator includes a gain stage, an inductor and two voltage-controlled capacitors, the gain stage includes a first Field Effect Transistor, a second Field Effect Transistor, a third Field Effect Transistor and a fourth Field Effect Transistor, the current auxiliary circuit is connected with an external power source and the follower that connected with the reference voltage terminal to provide a working voltage for the LC oscillator, the follower includes a detection circuit to detecting current changes of the gain stage. The LC oscillator process compensation circuit has simple circuit structure and eliminates frequency changes of the LC oscillator caused by the process variations of the gain stage, thereby ensuring stability of the frequency of the LC oscillator, improving work precision and reducing design difficult. | 04-16-2015 |
20150123743 | OSCILLATION CIRCUIT, OSCILLATOR, ELECTRONIC DEVICE, MOBILE OBJECT, AND OSCILLATOR MANUFACTURING METHOD - An oscillation circuit includes a circuit for frequency adjustment, a variable capacity control circuit in which a voltage to be output therefrom is controlled with either a voltage which is input from a terminal T | 05-07-2015 |
20160105187 | FLL OSCILLATOR/CLOCK WITH AN FLL CONTROL LOOP INCLUDING A SWITCHED CAPACITOR RESISTIVE DIVIDER - An FLL (frequency locked loop) oscillator/clock generator includes a free-running oscillator (such as a ring oscillator), and generates an FLL_clk with an FLL-controlled frequency f | 04-14-2016 |
20100148882 | VARIABLE INDUCTANCE CIRCUITRY FOR FREQUENCY CONTROL OF A VOLTAGE COUNTROLLED OSCILLATOR - An electronic device ( | 06-17-2010 |
331036000 | Capacitor controlled AFC | 49 |
20100026406 | Phase-locked loop circuit, recording-and-reproducing apparatus, and electronic appratus - A phase-locked loop circuit includes a phase detection unit, a loop filter unit including a series circuit of a resistor and a capacitor, first and second pulse-current output units which supply differential and single-end pulse currents corresponding to phase information to the resistor and capacitor, an oscillating unit which varies an oscillation frequency in accordance with a voltage generated at the resistor and capacitor, and a calibration unit which obtains information of an oscillation gain in actual operation and corrects an operation of the oscillating unit on the basis of a difference between the oscillation gain in actual operation and a target oscillation gain. The oscillation gain in actual operation represents a characteristic of oscillation frequency versus input signal of the oscillating unit and is obtained using predetermined oscillation control signals on the basis of a difference between actual oscillation frequencies under the oscillation control signals. | 02-04-2010 |
20100052803 | VOLTAGE CONTROLLED OSCILLATOR - An integrated circuit and an apparatus are provided. The integrated circuit comprises a bias circuit, an LC resonator circuit, and a current mode logic (CML) frequency divider. The bias circuit generates first and second bias voltages. The LC resonator circuit generates an oscillation signal having an oscillation frequency. The CML frequency divider, coupled to the bias circuit and the LC resonator circuit, biased by the first and second bias voltages, receives the oscillation signal to generate an output signal having an output frequency with a fractional rate of the oscillation frequency. The oscillation signal comprises AC and DC components, the CML frequency divider receives the AC component to determine an injected frequency and reuses the DC component to provide tail currents to determine a natural frequency of the CML frequency divider. The output frequency is determined by the injected frequency and the natural frequency. | 03-04-2010 |
20110267150 | Automatic Frequency Control Architecture with Digital Temperature Compensation - A mixed signal circuit architecture is disclosed for automatic frequency control and digital temperature compensation in an LC-PLL system. Some embodiments allow for high-volume manufacturing of products such as microprocessors and chipsets, and other circuits that employ LC-PLL technology. In some embodiments, various capacitor loadings can be selected to compensate for variation associated with process, voltage, temperature, and reference frequency. In addition, a multi-leg capacitor bank can be selectively used to further compensate for temperature variation post-lock, in accordance with some embodiments. A programmable timer can be used in some embodiments to allow for loop settling prior to assessing parameters of interest. | 11-03-2011 |
20130278347 | COMPENSATION FOR DIGITALLY CONTROLLED OSCILLATOR APPARATUS AND METHOD - Automatic digital sensing and compensation of frequency drift caused by temperature, aging, and/or other effects may be provided by including a compensation capacitor array and a sensing logic. The sensing logic may be configured to detect a drift in a first control signal and to provide the compensation capacitor array with a second control signal. The second control signal is configured to cause an adjustment of capacitance in the compensation capacitor array based on the detected drift in the first control signal. | 10-24-2013 |
20130328638 | VOLTAGE-CONTROLLED-OSCILLATOR (VCO) ARCHITECTURE FOR REDUCING DISTURBANCE - Operations of a signal generator, which may be configurable to generate signals at one or more particular frequencies, may be controlled. The controlling may occur by setting frequency of an output of the signal generator by setting one or both of impedance and capacitance associated with the signal generator; and tuning the signal generator by applying one or more adjustments to the impedance and the capacitance associated with the signal generator, to maintain the set frequency. The signal generator may comprise a phase-locked loop (PLL), comprising a voltage controlled oscillator (VCO) for use in generating oscillating signals driving the generation of the PLL output. The VCO may be configurable to generate signals at varying frequencies, and may comprise at least one impedance element, at least one variable capacitance element and a plurality of tuning branches, where each tuning branch comprises at least a static capacitance element and a switching element. | 12-12-2013 |
20140002206 | CIRCUIT REDUCING PHASE NOISE OF OSCILLATOR | 01-02-2014 |
20150061787 | METHOD AND APPARATUS FOR SUPPRESSING A DETERMINISTIC CLOCK JITTER - A method for generating an output clock comprising: detecting a timing difference between a first input clock and a second input clock to generate a phase error signal; generating a masked phase error signal by masking the phase error signal based on a deterministic jitter indicator signal; generating an oscillator control signal by filtering the masked phase error signal; and generating the output clock in accordance with the oscillator control signal. | 03-05-2015 |
20080238566 | High frequency oscillator circuit with feedback circuit of fet and short-stub transmission line - In a high frequency oscillator circuit including first and second field effect transistors, the first field effect transistor has a gate connected to a short-stub transmission line and a drain connected to an oscillation output terminal, and the second field effect transistor has a drain connected to a source of the first field effect transistor and a grounded source. The high frequency oscillator circuit oscillates by using a feedback circuit including the short-stub transmission line and the second field effect transistor. A feedback capacitor is further provided which is connected between a gate of the second field effect transistor and the drain of the first field effect transistor. | 10-02-2008 |
20080303603 | SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE - A semiconductor integrated circuit device includes a voltage controlled oscillator which controls a bias current or an oscillation frequency to supply an output signal, a phase-locked loop circuit which supplies a frequency control signal based on the output signal supplied from the voltage controlled oscillator, a peak detection circuit which detects a peak of the frequency control signal supplied from the phase-locked loop circuit, and a bias control circuit which produces a bias current based on the peak detected by the peak detection circuit to supply the bias current. The voltage controlled oscillator controls the bias current supplied from the bias control circuit or the oscillation frequency to supply the output signal based on the frequency control signal supplied from the phase-locked loop circuit. | 12-11-2008 |
20090002088 | DIGITAL CONTROLLED OSCILLATOR, FREQUENCY SYNTHESIZER, RADIO COMMUNICATION APPARATUS USING THE SAME, AND CONTROL METHOD FOR THE SAME - The digital controlled oscillator includes a variable capacitance section having a first capacitor array of a plurality of first variable capacitors and a second capacitor array of a plurality of second variable capacitors, and generates a signal having an oscillation frequency corresponding to the capacitance value of the variable capacitance section. The first capacitance change amount in the individual first variable capacitors is a value obtained by multiplying the second capacitance change amount in the individual second variable capacitors by an integer equal to or more than 2, and the number of second variable capacitors is equal to or more than a value obtained by subtracting 1 from the integer equal to or more than 2. | 01-01-2009 |
20090033433 | Circuits, Systems, and Methods for a Voltage Controlled Oscillator with Coarse, Fine, and Center Tuning - Circuits, systems, and methods for generating a variable oscillator output. The circuits generally comprise a capacitor configured to receive first and second currents of a first polarity (e.g., charging currents) and a third current of a second polarity opposite to the first polarity (e.g., a discharge current). The circuit further comprises a first circuit configured to receive a bias input, a second circuit configured to receive a coarse control input, and a third circuit configured to receive a fine control input. The first circuit is further configured to provide the first current in response to the bias input. The second circuit is further configured to provide the second current in response to the coarse control input, such that the second current generally has a magnitude of from zero to a multiple of the magnitude of the first current. The third circuit is further configured to provide the third current when the capacitor has a voltage that passes a threshold voltage determined by the fine control input. The present invention advantageously provides for producing a variable oscillator output over a broad range with the coarse control input, while also having low gain with the fine control input. The present invention is also advantageously suitable for standard integrated circuit manufacturing processes because the bias input can be adjusted to compensate for process variations. | 02-05-2009 |
20090033434 | OSCILLATION CIRCUIT - A first switch (SW | 02-05-2009 |
20090039973 | VCO driving circuit and frequency synthesizer - A VCO driving circuit and a frequency synthesizer wherein the impedance viewed from a VCO control terminal is reduced to prevent the VCO phase noise characteristic from degrading. A VCO driving circuit and a frequency synthesizer having the VCO driving circuit, which comprises a coarse adjustment DAC that receives a digital data, which has a coarse adjustment frequency, to output an analog signal; a fine adjustment DAC that receives a digital data, which has a fine adjustment frequency, to output an analog signal; a low response speed LPF | 02-12-2009 |
20090261917 | AUXILIARY VARACTOR FOR TEMPERATURE COMPENSATION - Techniques for compensating for the effects of temperature change on voltage controlled oscillator (VCO) frequency are disclosed. In an embodiment, an auxiliary varactor is coupled to an LC tank of the VCO. The auxiliary varactor has a capacitance controlled by a temperature-dependant control voltage to minimize the overall change in VCO frequency with temperature. Techniques for generating the control voltage using digital and analog means are further disclosed. | 10-22-2009 |
20090278620 | VCO CAPACITOR BANK TRIMMING AND CALIBRATION - Techniques are disclosed for trimming a capacitance associated with a capacitor bank for use in a voltage-controlled oscillator (VCO). In an embodiment, each capacitance is sub-divided into a plurality of constituent capacitances. The constituent capacitances may be selectively enabled or disabled to trim the step sizes of the capacitor bank. Further techniques are disclosed for calibrating the trimmable capacitance to minimize step size error for the capacitor bank. | 11-12-2009 |
20100007428 | OSCILLATION CIRCUIT - This oscillation circuit includes a triangular wave generation circuit that generates a triangular wave signal corresponding to an outputted clock signal, a comparison circuit that generates a clock signal corresponding to a comparison of the triangular wave signal with a first reference voltage and a second reference voltage, a current adjusting circuit that adjusts the value of adjusted current according to the power supply voltage for the comparison circuit, and a reference voltage generation circuit that generates the first reference voltage and the second reference voltage having a voltage differential that corresponds to the value of the adjusted current. The current adjusting circuit increases the adjusted current when the power supply voltage for the comparison circuit rises, and reduces the adjusted current when the power supply voltage drops. The reference voltage generation circuit increases the voltage differential between the first reference voltage and the second reference voltage when the adjusted current increases, and reduces the voltage differential when the adjusted current decreases. | 01-14-2010 |
20100026405 | Phase-locked loop circuit, recording-and-reproducing apparatus, and electronic apparatus - A phase-locked loop circuit includes a phase detection unit which detects phase information of an input signal, a loop filter unit including a series circuit of a resistor and a capacitor, first and second pulse-current output units which supply pulse currents corresponding to the phase information output to one and the other of the resistor and the capacitor, and an oscillating unit capable of varying an oscillation frequency in accordance with a component obtained by combining a voltage generated at both ends of the one of the resistor and the capacitor on the basis of the pulse current supplied from the output terminal of the first pulse-current output unit and a voltage generated at both ends of the other one of the resistor and the capacitor on the basis of the pulse current supplied from the output terminal of the second pulse-current output unit. | 02-04-2010 |
20100033260 | OSCILLATION CIRCUIT - An oscillation circuit according to an exemplary embodiment of the present invention includes: a power supply voltage terminal applied with a power supply voltage; a feedback loop circuit that outputs an oscillation frequency signal; and a correction circuit that corrects a time constant of the feedback loop circuit in accordance with the power supply voltage applied to the power supply voltage terminal. The configuration facilitates the correction of an oscillation frequency that varies depending on the fluctuation of the power supply voltage. | 02-11-2010 |
20100073101 | Low-noise voltage controlled oscillator - A low-noise voltage controlled oscillator is provided, to improve a phase noise characteristic and widen a frequency variable range. The low-noise voltage controlled oscillator is configured so that an oscillation element and a capacitor | 03-25-2010 |
20100123525 | Clock Control for Data Synchronization in Varactor Arrays - Implementations of varactor systems compare current data with immediately prior data to determine whether there has been a change in the data, and enable a clock signal for data paths which have changed data. | 05-20-2010 |
20100148881 | Digital Calibration Techniques for Segmented Capacitor Arrays - An apparatus includes phase detection circuitry that generates control signals in response to an input clock signal and a feedback clock signal. The apparatus also includes a clock signal generation circuit that includes fine and coarse capacitors. The clock signal generation circuit changes a capacitance of the capacitors that are affecting the output clock signal in response to a change in the control signals. The apparatus also includes measurement circuitry that determines a calibration number of the fine capacitors having a combined capacitance that most closely matches a capacitance of one of the coarse capacitors. | 06-17-2010 |
20100156550 | ADJUSTABLE CAPACITOR, DIGITALLY CONTROLLED OSCILLATOR, AND ALL-DIGITAL PHASE LOCKED LOOP - An adjustable capacitor is provided including a capacitor unit including a plurality of capacitor groups aligned in a matrix format and a switch unit to adjust capacitance by connecting the plurality of capacitor groups in parallel according to a selection signal of a column and row of the matrix. Accordingly, the adjustable capacitor may be realized of a small size but with a high capacitance change rate. | 06-24-2010 |
20100265001 | DIGITAL PLL CIRCUIT AND SEMICONDUCTOR INTEGRATED CIRCUIT - A digital PLL circuit includes: an oscillation circuit, wherein an oscillation frequency is controlled by changing the number of capacitance elements to be connected in parallel to an inductance element; and a phase comparator part configured to perform a digital phase comparison of a reference clock and a delayed clock thereof, with an oscillation circuit output; and based on the comparison result, to control the number of the capacitance elements so as to bring the phase of the oscillation circuit output closer to the reference clock phase, wherein the capacitance element includes: a coarse adjustment capacitor configured to have a predetermined capacitance; and fine adjustment capacitors configured to have a capacitance of 1/n of that of the coarse adjustment capacitor, wherein a predetermined number of the fine adjustment capacitors function as one coarse adjustment capacitor at the time of coarse adjustment. | 10-21-2010 |
20110080228 | Voltage controlled oscillator - To provide a voltage controlled oscillator capable of being treated as a lumped constant circuit, having small size and capable of obtaining an oscillation frequency in a high frequency band. A resonance part | 04-07-2011 |
20110121910 | PHASE LOCKED LOOP APPARATUS WITH SELECTABLE CAPACITANCE DEVICE - A phase locked loop apparatus includes an oscillator, a variable capacitance device, a selectable capacitance device, and a capacitance controller that is configured to provide a control signal to the selectable capacitance device. The selectable capacitance device is connected to the oscillator and is responsive to the control signal such that the selectable capacitance device has a first capacitance at a first control signal value and a second capacitance at a second control signal value. The capacitance controller only selects either the first capacitance or the second capacitance by providing a control signal that has the first control signal value to select the first capacitance and having the second control signal value to select the second capacitance. | 05-26-2011 |
20110221539 | OSCILLATOR WITH CONTROLLABLE FREQUENCY - Apparatuses are disclosed which comprise a coarse tuning circuitry, a fine tuning circuitry and at least one switchable capacitance. | 09-15-2011 |
20110234331 | INTEGRATED CIRCUITS WITH CONFIGURABLE INDUCTORS - Integrated circuits with phase-locked loops are provided. Phase-locked loops may include an oscillator, a phase-frequency detector, a charge pump, a loop filter, a voltage-controlled oscillator, and a programmable divider. The voltage-controlled oscillator may include multiple inductors, an oscillator circuit, and a buffer circuit. A selected one of the multiple inductors may be actively connected to the oscillator circuit. The voltage-controlled oscillators may have multiple oscillator circuits. Each oscillator circuit may be connected to a respective inductor, may include a varactor, and may be powered by a respective voltage regulator. Each oscillator circuit may be coupled to a respective input transistor pair in the buffer circuit through associated coupling capacitors. A selected one of the oscillator circuits may be turned on during normal operation by supplying a high voltage to the selected one of the oscillator circuit and by supply a ground voltage to the remaining oscillator circuits. | 09-29-2011 |
20120007686 | MULTIBAND VOLTAGE CONTROLLED OSCILLATOR WITHOUT SWITCHED CAPACITOR - A controlled oscillator includes, connected in parallel, a capacitor configured to be tuneable based upon a first signal, an inductor, and an active impedance. The active impedance is formed by a pair of cross-coupled transistors connected so as to produce a negative resistive component at the terminals of the active impedance. Circuitry produces a degeneracy tuneable by a second signal in the cross-coupled pair, such that the cross-coupled pair produces a capacitive component tuneable based upon the second signal at the terminals of the active impedance. | 01-12-2012 |
20120068780 | Systems and Methods for Reducing Frequency Pulling in an Oscillator Circuit - Methods and systems are provided to calibrate an oscillator circuit to reduce frequency pulling as a result of a change in power to a portion of the oscillator circuit. In an embodiment, an oscillator is coupled to a clock buffer circuit and a tuning capacitor configured to tune a frequency of the oscillator to a baseline frequency required for cellular communications. A change in power to the clock buffer circuit initiates a change in an amount of capacitance seen by the oscillator, which negatively impacts the tuning of the oscillator. A register stores a frequency offset caused by the change in power, and the tuning capacitor is adjusted, using the frequency offset, in response to the change in power, such that the total amount of capacitance seen by the oscillator is not changed when the change in power occurs. | 03-22-2012 |
20120119839 | PLL FREQUENCY SYNTHESIZER - Disclosed is a PLL frequency synthesizer the phase noise characteristics of which are improved. To achieve this, in an ADPLL frequency synthesizer ( | 05-17-2012 |
20120139654 | FREQUENCY SYNTHESIZER - A frequency synthesizer includes a control circuit configured to generate a digital control signal; and a digitally controlled oscillator of which oscillation frequency changes according to the generated digital control signal. The control circuit includes an operational circuit configured to divide an integer portion of a numerical value representing a phase difference between a reference signal and an oscillation frequency signal of the digitally controlled oscillator into high-order bits and low-order bits including a redundant bit as an MSB, and two encoders configured to encode the high-order bits and the low-order bits to generate control signals. The digitally controlled oscillator includes two capacitive element groups having capacitance values controlled by the control signals. The oscillation frequency of the digitally controlled oscillator changes according to a total capacitance value of the two capacitive element groups. | 06-07-2012 |
20120194286 | METHODS AND SYSTEMS FOR MEMS CMOS DEVICES HAVING ARRAYS OF ELEMENTS - Systems and methods for manufacturing a chip comprising a plurality of MEMS devices arranged in an integrated circuit are provided. In one aspect, the systems and methods provide for a chip including electronic elements formed on a semiconductor material substrate. The chip further includes a stack of interconnection layers including layers of conductor material separated by layers of dielectric material. MEMS devices are formed within the stack of interconnection layers by applying gaseous HF to a first layer of dielectric material positioned highest in the stack of interconnection layers. The stack of interconnection layers includes at least one unetched layer of dielectric material, and at least one layer of conductor material for routing connections to and from the electronic elements. | 08-02-2012 |
20120326797 | VCO UTILIZING AN AUXILIARY VARACTOR WITH TEMPERATURE DEPENDENT BIAS - A technique to use an auxiliary varactor coupled to a tuning varactor, in which a temperature compensated bias signal adjusts a bias on the auxiliary varactor to maintain a voltage controlled oscillator (VCO) from drifting in frequency as operating temperature for the VCO changes. | 12-27-2012 |
20130127555 | Systems and Methods for Reducing Frequency Pulling in an Oscillator Circuit - Methods and systems are provided to calibrate an oscillator circuit to reduce frequency pulling as a result of a change in power to a portion of the oscillator circuit. In an embodiment, an oscillator is coupled to a clock buffer circuit and a tuning capacitor configured to tune a frequency of the oscillator to a baseline frequency required for cellular communications. A change in power to the clock buffer circuit initiates a change in an amount of capacitance seen by the oscillator, which negatively impacts the tuning of the oscillator. A register stores a frequency offset caused by the change in power, and the tuning capacitor is adjusted, using the frequency offset, in response to the change in power, such that the total amount of capacitance seen by the oscillator is not changed when the change in power occurs. | 05-23-2013 |
20130154754 | TUNING OF MEMS OSCILLATOR - A method is provided for tuning a microelectromechanical systems (MEMS) oscillator comprising an acoustic resonator and a tuning and amplification circuit arranged in a loop. The method comprises determining an initial oscillation frequency of the oscillator, modifying a capacitance of the tuning and amplification circuit according to the initial oscillation frequency, and adjusting a power level of the oscillator according to the modified capacitance. | 06-20-2013 |
20130176082 | REFERENCE VOLTAGE GENERATION CIRCUIT, OSCILLATION CIRCUIT INCLUDING THE SAME AND METHOD FOR CALIBRATING OSCILLATION FREQUENCY OF OSCILLATION CIRCUIT - A reference voltage generation circuit has: a first PN junction element; a second PN junction element having a higher forward direction voltage than the first PN junction element; a first differential amplifier inputting an anode of the first PN junction element and a first connection node between a first and a second resistor disposed in series between a first output of the first differential amplifier and a first potential, and generating a first output voltage at the first output; and a second differential amplifier inputting an anode of the second PN junction element and a second connection node between a fourth and a third resistor disposed in series between a second output of the second differential amplifier and the first output of the first differential amplifier, and generating a reference voltage at the second output. A resistance ratio between the third and the fourth resistors is variable. | 07-11-2013 |
20130194050 | VOLTAGE CONTROLLED OSCILLATOR USING VARIABLE CAPACITOR AND PHASE LOCKED LOOP USING THE SAME - A variable capacitor is provided. The variable capacitor includes a plurality of capacitor segments. The plurality of capacitor segments are connected in parallel within the variable capacitor. When a plurality of candidate capacitances allowable to the variable capacitor according to a connection state of the plurality of capacitor segments connected in parallel are sorted in a magnitude sequence, the plurality of candidate capacitances form a geometric series. The variable capacitor is used for a Voltage Controlled Oscillator (VCO), and the VCO is used for a Phase Locked Loop (PLL). | 08-01-2013 |
20130234802 | METHOD AND APPARATUS FOR DRIFT COMPENSATION IN PLL - Aspects of the disclosure provide a phase-locked loop (PLL). The PLL includes a voltage-controlled oscillator (VCO), a detector module, and a ramp module. The VCO has a first capacitor unit and a second capacitor unit. The VCO is configured to generate an oscillating signal having a frequency based on a first capacitance of the first capacitor unit and a second capacitance of the second capacitor unit. The detector module is configured to generate a voltage signal as a function of the oscillating signal and a reference signal. The voltage signal is used to control the first capacitor unit to stabilize the frequency of the oscillating signal. The ramp module is configured to generate a ramp signal based on the voltage signal. The ramp signal is used to control the second capacitor unit to ramp the second capacitance from a first value to a second value. | 09-12-2013 |
20130257556 | SIGNAL PROCESSING APPARATUS, SIGNAL PROCESSING METHOD AND COMMUNICATION APPARATUS - Disclosed herein is a signal processing apparatus including: a voltage-controlled oscillation block having a parameter high in correlation with a filter; a measuring block configured to measure an oscillation frequency of the voltage-controlled oscillation block; and a control block configured to control the parameter of the filter by use of a measuring result of the oscillation frequency obtained by the measuring block. | 10-03-2013 |
20140002205 | FREQUENCY SYNTHESIZER APPARATUS AND METHODS FOR IMPROVING CAPACITOR CODE SEARCH ACCURACY USING LSB MODULATION | 01-02-2014 |
20140035691 | CAPACITIVE DIVIDER STRUCTURE - A capacitive divider structure, comprising: a first plurality of capacitive devices, each being selectively controlled in accordance with a first input control signal so as to alter the effective capacitance of the capacitive divider structure by a first amount; a second plurality of capacitive devices coupled in parallel with the first plurality of capacitive devices, each being selectively controlled in accordance with a second input control signal so as to alter the effective capacitance of the capacitive divider structure by a second amount; and at least one series capacitive device arranged in series with the second plurality of capacitive devices, such that the second amount is less than the first amount. | 02-06-2014 |
20140091872 | OSCILLATOR CIRCUIT, VIBRATORY DEVICE, ELECTRONIC APPARATUS, MOVING OBJECT, METHOD OF ADJUSTING VIBRATORY DEVICE, AND SENSITIVITY ADJUSTMENT CIRCUIT - An oscillator circuit includes a terminal T1, a terminal T2, a variable capacitance element having one end connected to the terminal T1, and a capacitance value varying in accordance with a frequency control signal, a variable capacitance element having one end connected to the terminal T2, and a capacitance value varying in accordance with the frequency control signal, a load capacitance circuit connected to the terminal T1, and a load capacitance circuit connected to the terminal T2, and oscillates a resonator element at a frequency corresponding to the frequency control signal. The oscillator circuit is capable of adjusting the capacitance values of the load capacitance circuits, a reference voltage (the electrical potential of the terminal T1), and a reference voltage (the electrical potential of the terminal T2) in accordance with configuration information. | 04-03-2014 |
20140118080 | FREQUENCY SYNTHESIZER - A digitally controlled frequency synthesizer less influenced by disturbance noise is provided without using a ΔΣ modulator. The frequency synthesizer, whose oscillation frequency is digitally controlled, includes a loop gain control section configured to generate digital control data for controlling a loop gain of the frequency synthesizer; a DA conversion section configured to convert lower bits of the digital control data to an analog voltage; and an oscillation section configured to oscillate at a frequency corresponding to higher bits of the digital control data and the analog voltage output from the DA conversion section. | 05-01-2014 |
20140152394 | FREQUENCY DETECTION CIRCUITS, RADIO FREQUENCY SIGNAL PROCESSING DEVICES AND METHODS FOR CALIBRATING INDUCTANCE AND CAPACITANCE - A frequency detection circuit includes a filter, a power detector and a voltage comparator. The filter receives and filters a converted signal to generate a filtered signal. The power of the filtered signal relates to a frequency of the converted signal. The power detector generates a voltage according to the power of the filtered signal. The voltage comparator compares the voltage with multiple reference voltages to generate multiple comparison results. At least one of the inductance and capacitance of an LC tank in an amplifier is adjusted according to the comparison results. | 06-05-2014 |
20140184348 | CIRCUIT FOR ADJUSTING FREQUENCY OF CRYSTAL OSCILLATOR - A circuit for adjusting frequency of a crystal oscillator includes a basic input output system (BIOS), a platform controller hub (PCH), a buffer, and a capacitor module with a number of capacitors. The crystal oscillator is connected to clock pins of the PCH. An input pin of the buffer is connected to the crystal oscillator. A first end of the each of the capacitors is connected to an output pin of the buffer. A second end of the each of the capacitors is grounded. The buffer includes two enable pins and a control unit controlled by the enable pins. The enable pins of the buffer receive a control signal from the PCH according to the BIOS, and control the control unit to appoint the corresponding capacitor of the capacitor module to be connected to the input pin of the buffer. | 07-03-2014 |
20140218124 | APPARATUS AND METHOD FOR GENERATING AN OSCILLATING OUTPUT SIGNAL - An apparatus for generating an oscillating output signal includes an inductive-capacitive (LC) circuit and a current tuning circuit. The LC circuit includes a primary inductor and a varactor coupled to the primary inductor. A capacitance of the varactor is responsive to a voltage at a control input of the varactor. The current tuning circuit includes a secondary inductor and a current driving circuit coupled to the secondary inductor. The current driving circuit is responsive to a current at a control input of the current driving circuit. An effective inductance of the primary inductor is adjustable via magnetic coupling to the secondary inductor, and a frequency of the oscillating output signal is responsive to the effective inductance of the primary inductor and to the capacitance of the varactor. | 08-07-2014 |
20140253255 | VOLTAGE CONTROLLED OSCILLATOR BAND-SELECT FAST SEARCHING USING PREDICTIVE SEARCHING - A method, an apparatus, and a computer program product are provided. The apparatus tunes a frequency provided by a VCO. The apparatus determines a relative capacitance change associated with a first frequency and a desired frequency from a look-up table. The apparatus adjusts a capacitor circuit in the VCO based on the determined relative capacitance change determined from the look-up table in order to tune from the first frequency to the desired frequency. The apparatus determines that the frequency provided by the VCO is a second frequency different than the desired frequency after adjusting the capacitor circuit. The apparatus performs an iterative search to further adjust the capacitor circuit when a difference between the second frequency and the desired frequency is greater than a threshold. | 09-11-2014 |
20140253256 | MONOLITHIC CLOCK GENERATOR AND TIMING/FREQUENCY REFERENCE - A periodic signal generator includes a resonant LC tank circuit that generates a periodic reference signal at a first frequency at a differential output thereof. A temperature-responsive frequency compensation module is electrically coupled to the differential output of the resonant LC tank circuit. This module includes a temperature dependent voltage control module that generates a temperature dependent control voltage and an array of switchable capacitive modules that is electrically coupled to a first node of the differential output of the resonant LC tank circuit and responsive to the temperature dependent control voltage and a plurality of switching coefficients. The array of switchable capacitive modules includes a fixed capacitor having a first terminal electrically coupled to the first node and a voltage-controlled variable capacitor having a first terminal electrically coupled to the first node. | 09-11-2014 |
20140340164 | CR OSCILLATION CIRCUIT - In a CR oscillation circuit, resistance elements forming a series circuit include a first resistance element having a large temperature coefficient of resistance and a second resistance element having a smaller temperature coefficient of resistance than the first resistance element. At least one of a capacitor and an oscillation resistance element is trimmable. A first switching circuit connected between the series circuit and a non-inverting input terminal of a comparator is turned on when an output signal of the comparator is at a high level, and a second switching circuit is turned on when the output signal is at a low level. | 11-20-2014 |
20140361846 | COMMUNICATION DEVICE AND CONTROL METHOD THEREOF - A communication device is provided in the present invention. The communication device comprises an oscillation signal source, a tunable capacitor array, a frame counter; and a control module. The control module is configured to jointly or separately control the tunable capacitor array and the frame counter to compensate a first frequency offset of the oscillation signal source when the communication device operates in a first mode, and to jointly or separately control the tunable capacitor array and the frame counter to compensate a second frequency offset of the oscillation signal source when the communication device operates in a second mode. | 12-11-2014 |
20150015343 | DEVICES AND METHODS FOR REDUCING NOISE IN DIGITALLY CONTROLLED OSCILLATORS - One feature pertains to a digitally controlled oscillator (DCO) that comprises a variable capacitor and noise reduction circuitry. The variable capacitor has a variable capacitance value that controls an output frequency of the DCO. The variable capacitance value is based on a first bank capacitance value provided by a first capacitor bank, a second bank capacitance value provided by a second capacitor bank, and an auxiliary bank capacitance value provided by an auxiliary capacitor bank. The noise reduction circuitry is adapted to adjust the variable capacitance value by adjusting the auxiliary bank capacitance value while maintaining at least one of the first bank capacitance value and/or the second bank capacitance value substantially unchanged. Prior to adjusting the variable capacitance value, the noise reduction circuitry may determine that a received input DCO control word transitions across a capacitor bank sensitive boundary. | 01-15-2015 |
20150077193 | VOLTAGE-CONTROLLED OSCILLATOR, SIGNAL GENERATION APPARATUS, AND ELECTRONIC DEVICE - The present invention is for, in a voltage-controlled oscillator in which the oscillation frequency can be adjusted using a capacitor array, reducing drift that occurs in the carrier frequency if the oscillation signal is subjected to frequency modulation after the control loop of the PLL circuit has been cut off. This voltage-controlled oscillator includes an oscillation circuit for performing an oscillation operation at a frequency that corresponds to an inductance and a capacitance between a first node and a second node, a first and second group of capacitors that have first terminals connected to the first node and the second node respectively, a first and second group of transistors that are respectively connected between a reference potential and second terminals of the first group and second group of capacitors, and a first and second group of resistors that are respectively parallel-connected to the first group and second group of transistors. | 03-19-2015 |
20150084711 | OSCILLATION CIRCUIT, ELECTRONIC APPARATUS, MOVING OBJECT, AND METHOD FOR MANUFACTURING OSCILLATION CIRCUIT - An oscillation circuit includes an oscillation amplifier circuit that causes an oscillating element to oscillate to generate an oscillation signal, and a correction circuit connected with the oscillation amplifier circuit. At least a power supply voltage is input to the oscillation amplifier circuit. The oscillation amplifier circuit has a frequency variation characteristic that the frequency of the oscillation signal varies in response to variations in the power supply voltage. The power supply voltage is input to the correction circuit. The correction circuit corrects the frequency variation characteristic by using variations in the power supply voltage. The correction circuit may include a first variable capacitance element, and the first variable capacitance element may have a capacitance-voltage characteristic by which the frequency variation characteristic is reduced. | 03-26-2015 |
20150102867 | LC OSCILLATOR PROCESS COMPENSATION CIRCUIT - An LC oscillator process compensation circuit includes an LC oscillator, a reference voltage terminal, a follower and a current auxiliary circuit, the LC oscillator includes a gain stage, an inductor and two voltage-controlled capacitors, the gain stage includes a first Field Effect Transistor, a second Field Effect Transistor, a third Field Effect Transistor and a fourth Field Effect Transistor, the current auxiliary circuit is connected with an external power source and the follower that connected with the reference voltage terminal to provide a working voltage for the LC oscillator, the follower includes a detection circuit to detecting current changes of the gain stage. The LC oscillator process compensation circuit has simple circuit structure and eliminates frequency changes of the LC oscillator caused by the process variations of the gain stage, thereby ensuring stability of the frequency of the LC oscillator, improving work precision and reducing design difficult. | 04-16-2015 |
20150123743 | OSCILLATION CIRCUIT, OSCILLATOR, ELECTRONIC DEVICE, MOBILE OBJECT, AND OSCILLATOR MANUFACTURING METHOD - An oscillation circuit includes a circuit for frequency adjustment, a variable capacity control circuit in which a voltage to be output therefrom is controlled with either a voltage which is input from a terminal T | 05-07-2015 |
20160105187 | FLL OSCILLATOR/CLOCK WITH AN FLL CONTROL LOOP INCLUDING A SWITCHED CAPACITOR RESISTIVE DIVIDER - An FLL (frequency locked loop) oscillator/clock generator includes a free-running oscillator (such as a ring oscillator), and generates an FLL_clk with an FLL-controlled frequency f | 04-14-2016 |
20100148882 | VARIABLE INDUCTANCE CIRCUITRY FOR FREQUENCY CONTROL OF A VOLTAGE COUNTROLLED OSCILLATOR - An electronic device ( | 06-17-2010 |
331036000 | Inductor controlled AFC | 1 |
20100026406 | Phase-locked loop circuit, recording-and-reproducing apparatus, and electronic appratus - A phase-locked loop circuit includes a phase detection unit, a loop filter unit including a series circuit of a resistor and a capacitor, first and second pulse-current output units which supply differential and single-end pulse currents corresponding to phase information to the resistor and capacitor, an oscillating unit which varies an oscillation frequency in accordance with a voltage generated at the resistor and capacitor, and a calibration unit which obtains information of an oscillation gain in actual operation and corrects an operation of the oscillating unit on the basis of a difference between the oscillation gain in actual operation and a target oscillation gain. The oscillation gain in actual operation represents a characteristic of oscillation frequency versus input signal of the oscillating unit and is obtained using predetermined oscillation control signals on the basis of a difference between actual oscillation frequencies under the oscillation control signals. | 02-04-2010 |
20100052803 | VOLTAGE CONTROLLED OSCILLATOR - An integrated circuit and an apparatus are provided. The integrated circuit comprises a bias circuit, an LC resonator circuit, and a current mode logic (CML) frequency divider. The bias circuit generates first and second bias voltages. The LC resonator circuit generates an oscillation signal having an oscillation frequency. The CML frequency divider, coupled to the bias circuit and the LC resonator circuit, biased by the first and second bias voltages, receives the oscillation signal to generate an output signal having an output frequency with a fractional rate of the oscillation frequency. The oscillation signal comprises AC and DC components, the CML frequency divider receives the AC component to determine an injected frequency and reuses the DC component to provide tail currents to determine a natural frequency of the CML frequency divider. The output frequency is determined by the injected frequency and the natural frequency. | 03-04-2010 |
20110267150 | Automatic Frequency Control Architecture with Digital Temperature Compensation - A mixed signal circuit architecture is disclosed for automatic frequency control and digital temperature compensation in an LC-PLL system. Some embodiments allow for high-volume manufacturing of products such as microprocessors and chipsets, and other circuits that employ LC-PLL technology. In some embodiments, various capacitor loadings can be selected to compensate for variation associated with process, voltage, temperature, and reference frequency. In addition, a multi-leg capacitor bank can be selectively used to further compensate for temperature variation post-lock, in accordance with some embodiments. A programmable timer can be used in some embodiments to allow for loop settling prior to assessing parameters of interest. | 11-03-2011 |
20130278347 | COMPENSATION FOR DIGITALLY CONTROLLED OSCILLATOR APPARATUS AND METHOD - Automatic digital sensing and compensation of frequency drift caused by temperature, aging, and/or other effects may be provided by including a compensation capacitor array and a sensing logic. The sensing logic may be configured to detect a drift in a first control signal and to provide the compensation capacitor array with a second control signal. The second control signal is configured to cause an adjustment of capacitance in the compensation capacitor array based on the detected drift in the first control signal. | 10-24-2013 |
20130328638 | VOLTAGE-CONTROLLED-OSCILLATOR (VCO) ARCHITECTURE FOR REDUCING DISTURBANCE - Operations of a signal generator, which may be configurable to generate signals at one or more particular frequencies, may be controlled. The controlling may occur by setting frequency of an output of the signal generator by setting one or both of impedance and capacitance associated with the signal generator; and tuning the signal generator by applying one or more adjustments to the impedance and the capacitance associated with the signal generator, to maintain the set frequency. The signal generator may comprise a phase-locked loop (PLL), comprising a voltage controlled oscillator (VCO) for use in generating oscillating signals driving the generation of the PLL output. The VCO may be configurable to generate signals at varying frequencies, and may comprise at least one impedance element, at least one variable capacitance element and a plurality of tuning branches, where each tuning branch comprises at least a static capacitance element and a switching element. | 12-12-2013 |
20140002206 | CIRCUIT REDUCING PHASE NOISE OF OSCILLATOR | 01-02-2014 |
20150061787 | METHOD AND APPARATUS FOR SUPPRESSING A DETERMINISTIC CLOCK JITTER - A method for generating an output clock comprising: detecting a timing difference between a first input clock and a second input clock to generate a phase error signal; generating a masked phase error signal by masking the phase error signal based on a deterministic jitter indicator signal; generating an oscillator control signal by filtering the masked phase error signal; and generating the output clock in accordance with the oscillator control signal. | 03-05-2015 |
20080238566 | High frequency oscillator circuit with feedback circuit of fet and short-stub transmission line - In a high frequency oscillator circuit including first and second field effect transistors, the first field effect transistor has a gate connected to a short-stub transmission line and a drain connected to an oscillation output terminal, and the second field effect transistor has a drain connected to a source of the first field effect transistor and a grounded source. The high frequency oscillator circuit oscillates by using a feedback circuit including the short-stub transmission line and the second field effect transistor. A feedback capacitor is further provided which is connected between a gate of the second field effect transistor and the drain of the first field effect transistor. | 10-02-2008 |
20080303603 | SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE - A semiconductor integrated circuit device includes a voltage controlled oscillator which controls a bias current or an oscillation frequency to supply an output signal, a phase-locked loop circuit which supplies a frequency control signal based on the output signal supplied from the voltage controlled oscillator, a peak detection circuit which detects a peak of the frequency control signal supplied from the phase-locked loop circuit, and a bias control circuit which produces a bias current based on the peak detected by the peak detection circuit to supply the bias current. The voltage controlled oscillator controls the bias current supplied from the bias control circuit or the oscillation frequency to supply the output signal based on the frequency control signal supplied from the phase-locked loop circuit. | 12-11-2008 |
20090002088 | DIGITAL CONTROLLED OSCILLATOR, FREQUENCY SYNTHESIZER, RADIO COMMUNICATION APPARATUS USING THE SAME, AND CONTROL METHOD FOR THE SAME - The digital controlled oscillator includes a variable capacitance section having a first capacitor array of a plurality of first variable capacitors and a second capacitor array of a plurality of second variable capacitors, and generates a signal having an oscillation frequency corresponding to the capacitance value of the variable capacitance section. The first capacitance change amount in the individual first variable capacitors is a value obtained by multiplying the second capacitance change amount in the individual second variable capacitors by an integer equal to or more than 2, and the number of second variable capacitors is equal to or more than a value obtained by subtracting 1 from the integer equal to or more than 2. | 01-01-2009 |
20090033433 | Circuits, Systems, and Methods for a Voltage Controlled Oscillator with Coarse, Fine, and Center Tuning - Circuits, systems, and methods for generating a variable oscillator output. The circuits generally comprise a capacitor configured to receive first and second currents of a first polarity (e.g., charging currents) and a third current of a second polarity opposite to the first polarity (e.g., a discharge current). The circuit further comprises a first circuit configured to receive a bias input, a second circuit configured to receive a coarse control input, and a third circuit configured to receive a fine control input. The first circuit is further configured to provide the first current in response to the bias input. The second circuit is further configured to provide the second current in response to the coarse control input, such that the second current generally has a magnitude of from zero to a multiple of the magnitude of the first current. The third circuit is further configured to provide the third current when the capacitor has a voltage that passes a threshold voltage determined by the fine control input. The present invention advantageously provides for producing a variable oscillator output over a broad range with the coarse control input, while also having low gain with the fine control input. The present invention is also advantageously suitable for standard integrated circuit manufacturing processes because the bias input can be adjusted to compensate for process variations. | 02-05-2009 |
20090033434 | OSCILLATION CIRCUIT - A first switch (SW | 02-05-2009 |
20090039973 | VCO driving circuit and frequency synthesizer - A VCO driving circuit and a frequency synthesizer wherein the impedance viewed from a VCO control terminal is reduced to prevent the VCO phase noise characteristic from degrading. A VCO driving circuit and a frequency synthesizer having the VCO driving circuit, which comprises a coarse adjustment DAC that receives a digital data, which has a coarse adjustment frequency, to output an analog signal; a fine adjustment DAC that receives a digital data, which has a fine adjustment frequency, to output an analog signal; a low response speed LPF | 02-12-2009 |
20090261917 | AUXILIARY VARACTOR FOR TEMPERATURE COMPENSATION - Techniques for compensating for the effects of temperature change on voltage controlled oscillator (VCO) frequency are disclosed. In an embodiment, an auxiliary varactor is coupled to an LC tank of the VCO. The auxiliary varactor has a capacitance controlled by a temperature-dependant control voltage to minimize the overall change in VCO frequency with temperature. Techniques for generating the control voltage using digital and analog means are further disclosed. | 10-22-2009 |
20090278620 | VCO CAPACITOR BANK TRIMMING AND CALIBRATION - Techniques are disclosed for trimming a capacitance associated with a capacitor bank for use in a voltage-controlled oscillator (VCO). In an embodiment, each capacitance is sub-divided into a plurality of constituent capacitances. The constituent capacitances may be selectively enabled or disabled to trim the step sizes of the capacitor bank. Further techniques are disclosed for calibrating the trimmable capacitance to minimize step size error for the capacitor bank. | 11-12-2009 |
20100007428 | OSCILLATION CIRCUIT - This oscillation circuit includes a triangular wave generation circuit that generates a triangular wave signal corresponding to an outputted clock signal, a comparison circuit that generates a clock signal corresponding to a comparison of the triangular wave signal with a first reference voltage and a second reference voltage, a current adjusting circuit that adjusts the value of adjusted current according to the power supply voltage for the comparison circuit, and a reference voltage generation circuit that generates the first reference voltage and the second reference voltage having a voltage differential that corresponds to the value of the adjusted current. The current adjusting circuit increases the adjusted current when the power supply voltage for the comparison circuit rises, and reduces the adjusted current when the power supply voltage drops. The reference voltage generation circuit increases the voltage differential between the first reference voltage and the second reference voltage when the adjusted current increases, and reduces the voltage differential when the adjusted current decreases. | 01-14-2010 |
20100026405 | Phase-locked loop circuit, recording-and-reproducing apparatus, and electronic apparatus - A phase-locked loop circuit includes a phase detection unit which detects phase information of an input signal, a loop filter unit including a series circuit of a resistor and a capacitor, first and second pulse-current output units which supply pulse currents corresponding to the phase information output to one and the other of the resistor and the capacitor, and an oscillating unit capable of varying an oscillation frequency in accordance with a component obtained by combining a voltage generated at both ends of the one of the resistor and the capacitor on the basis of the pulse current supplied from the output terminal of the first pulse-current output unit and a voltage generated at both ends of the other one of the resistor and the capacitor on the basis of the pulse current supplied from the output terminal of the second pulse-current output unit. | 02-04-2010 |
20100033260 | OSCILLATION CIRCUIT - An oscillation circuit according to an exemplary embodiment of the present invention includes: a power supply voltage terminal applied with a power supply voltage; a feedback loop circuit that outputs an oscillation frequency signal; and a correction circuit that corrects a time constant of the feedback loop circuit in accordance with the power supply voltage applied to the power supply voltage terminal. The configuration facilitates the correction of an oscillation frequency that varies depending on the fluctuation of the power supply voltage. | 02-11-2010 |
20100073101 | Low-noise voltage controlled oscillator - A low-noise voltage controlled oscillator is provided, to improve a phase noise characteristic and widen a frequency variable range. The low-noise voltage controlled oscillator is configured so that an oscillation element and a capacitor | 03-25-2010 |
20100123525 | Clock Control for Data Synchronization in Varactor Arrays - Implementations of varactor systems compare current data with immediately prior data to determine whether there has been a change in the data, and enable a clock signal for data paths which have changed data. | 05-20-2010 |
20100148881 | Digital Calibration Techniques for Segmented Capacitor Arrays - An apparatus includes phase detection circuitry that generates control signals in response to an input clock signal and a feedback clock signal. The apparatus also includes a clock signal generation circuit that includes fine and coarse capacitors. The clock signal generation circuit changes a capacitance of the capacitors that are affecting the output clock signal in response to a change in the control signals. The apparatus also includes measurement circuitry that determines a calibration number of the fine capacitors having a combined capacitance that most closely matches a capacitance of one of the coarse capacitors. | 06-17-2010 |
20100156550 | ADJUSTABLE CAPACITOR, DIGITALLY CONTROLLED OSCILLATOR, AND ALL-DIGITAL PHASE LOCKED LOOP - An adjustable capacitor is provided including a capacitor unit including a plurality of capacitor groups aligned in a matrix format and a switch unit to adjust capacitance by connecting the plurality of capacitor groups in parallel according to a selection signal of a column and row of the matrix. Accordingly, the adjustable capacitor may be realized of a small size but with a high capacitance change rate. | 06-24-2010 |
20100265001 | DIGITAL PLL CIRCUIT AND SEMICONDUCTOR INTEGRATED CIRCUIT - A digital PLL circuit includes: an oscillation circuit, wherein an oscillation frequency is controlled by changing the number of capacitance elements to be connected in parallel to an inductance element; and a phase comparator part configured to perform a digital phase comparison of a reference clock and a delayed clock thereof, with an oscillation circuit output; and based on the comparison result, to control the number of the capacitance elements so as to bring the phase of the oscillation circuit output closer to the reference clock phase, wherein the capacitance element includes: a coarse adjustment capacitor configured to have a predetermined capacitance; and fine adjustment capacitors configured to have a capacitance of 1/n of that of the coarse adjustment capacitor, wherein a predetermined number of the fine adjustment capacitors function as one coarse adjustment capacitor at the time of coarse adjustment. | 10-21-2010 |
20110080228 | Voltage controlled oscillator - To provide a voltage controlled oscillator capable of being treated as a lumped constant circuit, having small size and capable of obtaining an oscillation frequency in a high frequency band. A resonance part | 04-07-2011 |
20110121910 | PHASE LOCKED LOOP APPARATUS WITH SELECTABLE CAPACITANCE DEVICE - A phase locked loop apparatus includes an oscillator, a variable capacitance device, a selectable capacitance device, and a capacitance controller that is configured to provide a control signal to the selectable capacitance device. The selectable capacitance device is connected to the oscillator and is responsive to the control signal such that the selectable capacitance device has a first capacitance at a first control signal value and a second capacitance at a second control signal value. The capacitance controller only selects either the first capacitance or the second capacitance by providing a control signal that has the first control signal value to select the first capacitance and having the second control signal value to select the second capacitance. | 05-26-2011 |
20110221539 | OSCILLATOR WITH CONTROLLABLE FREQUENCY - Apparatuses are disclosed which comprise a coarse tuning circuitry, a fine tuning circuitry and at least one switchable capacitance. | 09-15-2011 |
20110234331 | INTEGRATED CIRCUITS WITH CONFIGURABLE INDUCTORS - Integrated circuits with phase-locked loops are provided. Phase-locked loops may include an oscillator, a phase-frequency detector, a charge pump, a loop filter, a voltage-controlled oscillator, and a programmable divider. The voltage-controlled oscillator may include multiple inductors, an oscillator circuit, and a buffer circuit. A selected one of the multiple inductors may be actively connected to the oscillator circuit. The voltage-controlled oscillators may have multiple oscillator circuits. Each oscillator circuit may be connected to a respective inductor, may include a varactor, and may be powered by a respective voltage regulator. Each oscillator circuit may be coupled to a respective input transistor pair in the buffer circuit through associated coupling capacitors. A selected one of the oscillator circuits may be turned on during normal operation by supplying a high voltage to the selected one of the oscillator circuit and by supply a ground voltage to the remaining oscillator circuits. | 09-29-2011 |
20120007686 | MULTIBAND VOLTAGE CONTROLLED OSCILLATOR WITHOUT SWITCHED CAPACITOR - A controlled oscillator includes, connected in parallel, a capacitor configured to be tuneable based upon a first signal, an inductor, and an active impedance. The active impedance is formed by a pair of cross-coupled transistors connected so as to produce a negative resistive component at the terminals of the active impedance. Circuitry produces a degeneracy tuneable by a second signal in the cross-coupled pair, such that the cross-coupled pair produces a capacitive component tuneable based upon the second signal at the terminals of the active impedance. | 01-12-2012 |
20120068780 | Systems and Methods for Reducing Frequency Pulling in an Oscillator Circuit - Methods and systems are provided to calibrate an oscillator circuit to reduce frequency pulling as a result of a change in power to a portion of the oscillator circuit. In an embodiment, an oscillator is coupled to a clock buffer circuit and a tuning capacitor configured to tune a frequency of the oscillator to a baseline frequency required for cellular communications. A change in power to the clock buffer circuit initiates a change in an amount of capacitance seen by the oscillator, which negatively impacts the tuning of the oscillator. A register stores a frequency offset caused by the change in power, and the tuning capacitor is adjusted, using the frequency offset, in response to the change in power, such that the total amount of capacitance seen by the oscillator is not changed when the change in power occurs. | 03-22-2012 |
20120119839 | PLL FREQUENCY SYNTHESIZER - Disclosed is a PLL frequency synthesizer the phase noise characteristics of which are improved. To achieve this, in an ADPLL frequency synthesizer ( | 05-17-2012 |
20120139654 | FREQUENCY SYNTHESIZER - A frequency synthesizer includes a control circuit configured to generate a digital control signal; and a digitally controlled oscillator of which oscillation frequency changes according to the generated digital control signal. The control circuit includes an operational circuit configured to divide an integer portion of a numerical value representing a phase difference between a reference signal and an oscillation frequency signal of the digitally controlled oscillator into high-order bits and low-order bits including a redundant bit as an MSB, and two encoders configured to encode the high-order bits and the low-order bits to generate control signals. The digitally controlled oscillator includes two capacitive element groups having capacitance values controlled by the control signals. The oscillation frequency of the digitally controlled oscillator changes according to a total capacitance value of the two capacitive element groups. | 06-07-2012 |
20120194286 | METHODS AND SYSTEMS FOR MEMS CMOS DEVICES HAVING ARRAYS OF ELEMENTS - Systems and methods for manufacturing a chip comprising a plurality of MEMS devices arranged in an integrated circuit are provided. In one aspect, the systems and methods provide for a chip including electronic elements formed on a semiconductor material substrate. The chip further includes a stack of interconnection layers including layers of conductor material separated by layers of dielectric material. MEMS devices are formed within the stack of interconnection layers by applying gaseous HF to a first layer of dielectric material positioned highest in the stack of interconnection layers. The stack of interconnection layers includes at least one unetched layer of dielectric material, and at least one layer of conductor material for routing connections to and from the electronic elements. | 08-02-2012 |
20120326797 | VCO UTILIZING AN AUXILIARY VARACTOR WITH TEMPERATURE DEPENDENT BIAS - A technique to use an auxiliary varactor coupled to a tuning varactor, in which a temperature compensated bias signal adjusts a bias on the auxiliary varactor to maintain a voltage controlled oscillator (VCO) from drifting in frequency as operating temperature for the VCO changes. | 12-27-2012 |
20130127555 | Systems and Methods for Reducing Frequency Pulling in an Oscillator Circuit - Methods and systems are provided to calibrate an oscillator circuit to reduce frequency pulling as a result of a change in power to a portion of the oscillator circuit. In an embodiment, an oscillator is coupled to a clock buffer circuit and a tuning capacitor configured to tune a frequency of the oscillator to a baseline frequency required for cellular communications. A change in power to the clock buffer circuit initiates a change in an amount of capacitance seen by the oscillator, which negatively impacts the tuning of the oscillator. A register stores a frequency offset caused by the change in power, and the tuning capacitor is adjusted, using the frequency offset, in response to the change in power, such that the total amount of capacitance seen by the oscillator is not changed when the change in power occurs. | 05-23-2013 |
20130154754 | TUNING OF MEMS OSCILLATOR - A method is provided for tuning a microelectromechanical systems (MEMS) oscillator comprising an acoustic resonator and a tuning and amplification circuit arranged in a loop. The method comprises determining an initial oscillation frequency of the oscillator, modifying a capacitance of the tuning and amplification circuit according to the initial oscillation frequency, and adjusting a power level of the oscillator according to the modified capacitance. | 06-20-2013 |
20130176082 | REFERENCE VOLTAGE GENERATION CIRCUIT, OSCILLATION CIRCUIT INCLUDING THE SAME AND METHOD FOR CALIBRATING OSCILLATION FREQUENCY OF OSCILLATION CIRCUIT - A reference voltage generation circuit has: a first PN junction element; a second PN junction element having a higher forward direction voltage than the first PN junction element; a first differential amplifier inputting an anode of the first PN junction element and a first connection node between a first and a second resistor disposed in series between a first output of the first differential amplifier and a first potential, and generating a first output voltage at the first output; and a second differential amplifier inputting an anode of the second PN junction element and a second connection node between a fourth and a third resistor disposed in series between a second output of the second differential amplifier and the first output of the first differential amplifier, and generating a reference voltage at the second output. A resistance ratio between the third and the fourth resistors is variable. | 07-11-2013 |
20130194050 | VOLTAGE CONTROLLED OSCILLATOR USING VARIABLE CAPACITOR AND PHASE LOCKED LOOP USING THE SAME - A variable capacitor is provided. The variable capacitor includes a plurality of capacitor segments. The plurality of capacitor segments are connected in parallel within the variable capacitor. When a plurality of candidate capacitances allowable to the variable capacitor according to a connection state of the plurality of capacitor segments connected in parallel are sorted in a magnitude sequence, the plurality of candidate capacitances form a geometric series. The variable capacitor is used for a Voltage Controlled Oscillator (VCO), and the VCO is used for a Phase Locked Loop (PLL). | 08-01-2013 |
20130234802 | METHOD AND APPARATUS FOR DRIFT COMPENSATION IN PLL - Aspects of the disclosure provide a phase-locked loop (PLL). The PLL includes a voltage-controlled oscillator (VCO), a detector module, and a ramp module. The VCO has a first capacitor unit and a second capacitor unit. The VCO is configured to generate an oscillating signal having a frequency based on a first capacitance of the first capacitor unit and a second capacitance of the second capacitor unit. The detector module is configured to generate a voltage signal as a function of the oscillating signal and a reference signal. The voltage signal is used to control the first capacitor unit to stabilize the frequency of the oscillating signal. The ramp module is configured to generate a ramp signal based on the voltage signal. The ramp signal is used to control the second capacitor unit to ramp the second capacitance from a first value to a second value. | 09-12-2013 |
20130257556 | SIGNAL PROCESSING APPARATUS, SIGNAL PROCESSING METHOD AND COMMUNICATION APPARATUS - Disclosed herein is a signal processing apparatus including: a voltage-controlled oscillation block having a parameter high in correlation with a filter; a measuring block configured to measure an oscillation frequency of the voltage-controlled oscillation block; and a control block configured to control the parameter of the filter by use of a measuring result of the oscillation frequency obtained by the measuring block. | 10-03-2013 |
20140002205 | FREQUENCY SYNTHESIZER APPARATUS AND METHODS FOR IMPROVING CAPACITOR CODE SEARCH ACCURACY USING LSB MODULATION | 01-02-2014 |
20140035691 | CAPACITIVE DIVIDER STRUCTURE - A capacitive divider structure, comprising: a first plurality of capacitive devices, each being selectively controlled in accordance with a first input control signal so as to alter the effective capacitance of the capacitive divider structure by a first amount; a second plurality of capacitive devices coupled in parallel with the first plurality of capacitive devices, each being selectively controlled in accordance with a second input control signal so as to alter the effective capacitance of the capacitive divider structure by a second amount; and at least one series capacitive device arranged in series with the second plurality of capacitive devices, such that the second amount is less than the first amount. | 02-06-2014 |
20140091872 | OSCILLATOR CIRCUIT, VIBRATORY DEVICE, ELECTRONIC APPARATUS, MOVING OBJECT, METHOD OF ADJUSTING VIBRATORY DEVICE, AND SENSITIVITY ADJUSTMENT CIRCUIT - An oscillator circuit includes a terminal T1, a terminal T2, a variable capacitance element having one end connected to the terminal T1, and a capacitance value varying in accordance with a frequency control signal, a variable capacitance element having one end connected to the terminal T2, and a capacitance value varying in accordance with the frequency control signal, a load capacitance circuit connected to the terminal T1, and a load capacitance circuit connected to the terminal T2, and oscillates a resonator element at a frequency corresponding to the frequency control signal. The oscillator circuit is capable of adjusting the capacitance values of the load capacitance circuits, a reference voltage (the electrical potential of the terminal T1), and a reference voltage (the electrical potential of the terminal T2) in accordance with configuration information. | 04-03-2014 |
20140118080 | FREQUENCY SYNTHESIZER - A digitally controlled frequency synthesizer less influenced by disturbance noise is provided without using a ΔΣ modulator. The frequency synthesizer, whose oscillation frequency is digitally controlled, includes a loop gain control section configured to generate digital control data for controlling a loop gain of the frequency synthesizer; a DA conversion section configured to convert lower bits of the digital control data to an analog voltage; and an oscillation section configured to oscillate at a frequency corresponding to higher bits of the digital control data and the analog voltage output from the DA conversion section. | 05-01-2014 |
20140152394 | FREQUENCY DETECTION CIRCUITS, RADIO FREQUENCY SIGNAL PROCESSING DEVICES AND METHODS FOR CALIBRATING INDUCTANCE AND CAPACITANCE - A frequency detection circuit includes a filter, a power detector and a voltage comparator. The filter receives and filters a converted signal to generate a filtered signal. The power of the filtered signal relates to a frequency of the converted signal. The power detector generates a voltage according to the power of the filtered signal. The voltage comparator compares the voltage with multiple reference voltages to generate multiple comparison results. At least one of the inductance and capacitance of an LC tank in an amplifier is adjusted according to the comparison results. | 06-05-2014 |
20140184348 | CIRCUIT FOR ADJUSTING FREQUENCY OF CRYSTAL OSCILLATOR - A circuit for adjusting frequency of a crystal oscillator includes a basic input output system (BIOS), a platform controller hub (PCH), a buffer, and a capacitor module with a number of capacitors. The crystal oscillator is connected to clock pins of the PCH. An input pin of the buffer is connected to the crystal oscillator. A first end of the each of the capacitors is connected to an output pin of the buffer. A second end of the each of the capacitors is grounded. The buffer includes two enable pins and a control unit controlled by the enable pins. The enable pins of the buffer receive a control signal from the PCH according to the BIOS, and control the control unit to appoint the corresponding capacitor of the capacitor module to be connected to the input pin of the buffer. | 07-03-2014 |
20140218124 | APPARATUS AND METHOD FOR GENERATING AN OSCILLATING OUTPUT SIGNAL - An apparatus for generating an oscillating output signal includes an inductive-capacitive (LC) circuit and a current tuning circuit. The LC circuit includes a primary inductor and a varactor coupled to the primary inductor. A capacitance of the varactor is responsive to a voltage at a control input of the varactor. The current tuning circuit includes a secondary inductor and a current driving circuit coupled to the secondary inductor. The current driving circuit is responsive to a current at a control input of the current driving circuit. An effective inductance of the primary inductor is adjustable via magnetic coupling to the secondary inductor, and a frequency of the oscillating output signal is responsive to the effective inductance of the primary inductor and to the capacitance of the varactor. | 08-07-2014 |
20140253255 | VOLTAGE CONTROLLED OSCILLATOR BAND-SELECT FAST SEARCHING USING PREDICTIVE SEARCHING - A method, an apparatus, and a computer program product are provided. The apparatus tunes a frequency provided by a VCO. The apparatus determines a relative capacitance change associated with a first frequency and a desired frequency from a look-up table. The apparatus adjusts a capacitor circuit in the VCO based on the determined relative capacitance change determined from the look-up table in order to tune from the first frequency to the desired frequency. The apparatus determines that the frequency provided by the VCO is a second frequency different than the desired frequency after adjusting the capacitor circuit. The apparatus performs an iterative search to further adjust the capacitor circuit when a difference between the second frequency and the desired frequency is greater than a threshold. | 09-11-2014 |
20140253256 | MONOLITHIC CLOCK GENERATOR AND TIMING/FREQUENCY REFERENCE - A periodic signal generator includes a resonant LC tank circuit that generates a periodic reference signal at a first frequency at a differential output thereof. A temperature-responsive frequency compensation module is electrically coupled to the differential output of the resonant LC tank circuit. This module includes a temperature dependent voltage control module that generates a temperature dependent control voltage and an array of switchable capacitive modules that is electrically coupled to a first node of the differential output of the resonant LC tank circuit and responsive to the temperature dependent control voltage and a plurality of switching coefficients. The array of switchable capacitive modules includes a fixed capacitor having a first terminal electrically coupled to the first node and a voltage-controlled variable capacitor having a first terminal electrically coupled to the first node. | 09-11-2014 |
20140340164 | CR OSCILLATION CIRCUIT - In a CR oscillation circuit, resistance elements forming a series circuit include a first resistance element having a large temperature coefficient of resistance and a second resistance element having a smaller temperature coefficient of resistance than the first resistance element. At least one of a capacitor and an oscillation resistance element is trimmable. A first switching circuit connected between the series circuit and a non-inverting input terminal of a comparator is turned on when an output signal of the comparator is at a high level, and a second switching circuit is turned on when the output signal is at a low level. | 11-20-2014 |
20140361846 | COMMUNICATION DEVICE AND CONTROL METHOD THEREOF - A communication device is provided in the present invention. The communication device comprises an oscillation signal source, a tunable capacitor array, a frame counter; and a control module. The control module is configured to jointly or separately control the tunable capacitor array and the frame counter to compensate a first frequency offset of the oscillation signal source when the communication device operates in a first mode, and to jointly or separately control the tunable capacitor array and the frame counter to compensate a second frequency offset of the oscillation signal source when the communication device operates in a second mode. | 12-11-2014 |
20150015343 | DEVICES AND METHODS FOR REDUCING NOISE IN DIGITALLY CONTROLLED OSCILLATORS - One feature pertains to a digitally controlled oscillator (DCO) that comprises a variable capacitor and noise reduction circuitry. The variable capacitor has a variable capacitance value that controls an output frequency of the DCO. The variable capacitance value is based on a first bank capacitance value provided by a first capacitor bank, a second bank capacitance value provided by a second capacitor bank, and an auxiliary bank capacitance value provided by an auxiliary capacitor bank. The noise reduction circuitry is adapted to adjust the variable capacitance value by adjusting the auxiliary bank capacitance value while maintaining at least one of the first bank capacitance value and/or the second bank capacitance value substantially unchanged. Prior to adjusting the variable capacitance value, the noise reduction circuitry may determine that a received input DCO control word transitions across a capacitor bank sensitive boundary. | 01-15-2015 |
20150077193 | VOLTAGE-CONTROLLED OSCILLATOR, SIGNAL GENERATION APPARATUS, AND ELECTRONIC DEVICE - The present invention is for, in a voltage-controlled oscillator in which the oscillation frequency can be adjusted using a capacitor array, reducing drift that occurs in the carrier frequency if the oscillation signal is subjected to frequency modulation after the control loop of the PLL circuit has been cut off. This voltage-controlled oscillator includes an oscillation circuit for performing an oscillation operation at a frequency that corresponds to an inductance and a capacitance between a first node and a second node, a first and second group of capacitors that have first terminals connected to the first node and the second node respectively, a first and second group of transistors that are respectively connected between a reference potential and second terminals of the first group and second group of capacitors, and a first and second group of resistors that are respectively parallel-connected to the first group and second group of transistors. | 03-19-2015 |
20150084711 | OSCILLATION CIRCUIT, ELECTRONIC APPARATUS, MOVING OBJECT, AND METHOD FOR MANUFACTURING OSCILLATION CIRCUIT - An oscillation circuit includes an oscillation amplifier circuit that causes an oscillating element to oscillate to generate an oscillation signal, and a correction circuit connected with the oscillation amplifier circuit. At least a power supply voltage is input to the oscillation amplifier circuit. The oscillation amplifier circuit has a frequency variation characteristic that the frequency of the oscillation signal varies in response to variations in the power supply voltage. The power supply voltage is input to the correction circuit. The correction circuit corrects the frequency variation characteristic by using variations in the power supply voltage. The correction circuit may include a first variable capacitance element, and the first variable capacitance element may have a capacitance-voltage characteristic by which the frequency variation characteristic is reduced. | 03-26-2015 |
20150102867 | LC OSCILLATOR PROCESS COMPENSATION CIRCUIT - An LC oscillator process compensation circuit includes an LC oscillator, a reference voltage terminal, a follower and a current auxiliary circuit, the LC oscillator includes a gain stage, an inductor and two voltage-controlled capacitors, the gain stage includes a first Field Effect Transistor, a second Field Effect Transistor, a third Field Effect Transistor and a fourth Field Effect Transistor, the current auxiliary circuit is connected with an external power source and the follower that connected with the reference voltage terminal to provide a working voltage for the LC oscillator, the follower includes a detection circuit to detecting current changes of the gain stage. The LC oscillator process compensation circuit has simple circuit structure and eliminates frequency changes of the LC oscillator caused by the process variations of the gain stage, thereby ensuring stability of the frequency of the LC oscillator, improving work precision and reducing design difficult. | 04-16-2015 |
20150123743 | OSCILLATION CIRCUIT, OSCILLATOR, ELECTRONIC DEVICE, MOBILE OBJECT, AND OSCILLATOR MANUFACTURING METHOD - An oscillation circuit includes a circuit for frequency adjustment, a variable capacity control circuit in which a voltage to be output therefrom is controlled with either a voltage which is input from a terminal T | 05-07-2015 |
20160105187 | FLL OSCILLATOR/CLOCK WITH AN FLL CONTROL LOOP INCLUDING A SWITCHED CAPACITOR RESISTIVE DIVIDER - An FLL (frequency locked loop) oscillator/clock generator includes a free-running oscillator (such as a ring oscillator), and generates an FLL_clk with an FLL-controlled frequency f | 04-14-2016 |
20100148882 | VARIABLE INDUCTANCE CIRCUITRY FOR FREQUENCY CONTROL OF A VOLTAGE COUNTROLLED OSCILLATOR - An electronic device ( | 06-17-2010 |