Patent application number | Description | Published |
20080232443 | SIGNAL GENERATING APPARATUS - A signal generating apparatus for generating a synthesized signal according to an input signal is provided. The signal generating apparatus includes a phase-locked loop device and a control unit. The phase-locked loop device has a phase/frequency detector for generating a detected signal according to a reference oscillating signal and a feedback signal, a control signal generator for generating a control signal according to the detected signal, a voltage controlled oscillator for generating the synthesized signal according to the control signal, and a divider for dividing the synthesized signal according to a dividing factor to generate the feedback signal. The control unit is for controlling the control signal generator to adjust the control signal in a calibration mode to thereby adjust a frequency of the synthesized signal. The phase/frequency detector does not output the detected signal to the control signal generator in the calibration mode. | 09-25-2008 |
20080253492 | CIRCUIT AND METHOD FOR CONTROLLING MIXED MODE CONTROLLED OSCILLATOR AND CDR CIRCUIT USING THE SAME - A circuit for controlling a mixed mode controlled oscillator. The circuit comprises a charge pump, and a digital loop filter. The charge pump is coupled to the mixed mode controlled oscillator. The charge pump receives an up/down signal and sends a current signal to the mixed mode controlled oscillator. The digital loop filter receives the up/down signal and generates a digital code signal to the mixed mode controlled oscillator. An output frequency of the mixed mode controlled oscillator is controlled by the current signal and the digital code signal. | 10-16-2008 |
20090096537 | Digital-Controlled Oscillator for Eliminating Frequency Discontinuities AND ALL-DIGITAL PHASE-LOCKED LOOP USING THE SAME - A digital-controlled oscillator (DCO) is utilized in an all-digital phase-locked loop for eliminating frequency discontinuities. The DCO includes a tank module and a negative gm cell. The tank module comprises a plurality of cells, at least a portion of the cells comprising a first tracking set and a second tracking set for respectively handling an odd bit or an even bit. The odd bit and the even bit are related to an integer signal, a fractional signal or a combination thereof, the fractional signal is indicated by a primary voltage inputted to the DCO. With the DCO, frequency discontinuities and undesired spurs are eliminated. | 04-16-2009 |
20090096538 | ALL-DIGITAL PHASE-LOCKED LOOP, LOOP BANDWIDTH CALIBRATION METHOD, AND LOOP GAIN CALIBRATION METHOD FOR THE SAME - For decreasing errors within an analog phase-locked loop, an all-digital phase-locked loop (ADPLL) with digital components and digital operations is used. The ADPLL may also be used for direct frequency modulation (DFM). By defining a proportional path gain of an ADPLL by a bandwidth and a reference frequency of the ADPLL, by a TDC gain, a DCO gain, a dividing ratio of a frequency divider, a gain of an amplifier or a combination thereof, the gain of the amplifier may be adjusted so that an optimal loop bandwidth of the ADPLL may be well calibrated. For achieving the aim of entirely digital of the ADPLL, the gains of the TDC and the DCO may be further adjusted in a digital manner. | 04-16-2009 |
20090128201 | CLOCK GENERATORS AND CLOCK GENERATION METHODS THEREOF - Clock generators are provided. A phase locked loop generates an output clock, a delay line is coupled to an input of the phase locked loop, and a modulation unit integrates an input signal with a constant level to generate a modulation signal controlling the delay line, thereby modulating a phase of a first input clock of the phase locked loop, such that frequency of the output clock is locked at a desired frequency. | 05-21-2009 |
20090129524 | SPREAD SPECTRUM CLOCK GENERATORS - Spread spectrum clock generators. A phase lock loop generates an output clock according to a first input clock and a second input clock, a delay line is coupled between the first input clock and the phase lock loop. A modulation unit provides a modulation signal to control the delay line thereby modulating phase of the first input clock, such that frequency of the output clock generated by the phase lock loop varies periodically. | 05-21-2009 |
20090174491 | Mixed-Mode PLL - A mixed-mode PLL is disclosed. The mixed-mode PLL comprises an analog phase correction path and a digital frequency correction path. The analog phase correction path comprises a linear phase correction unit (LPCU). The digital frequency correction path comprises a digital integral path circuit. | 07-09-2009 |
20090201093 | PHASE-LOCKED CIRCUIT EMPLOYING CAPACITANCE MULTIPLICATION - A phase-locked loop circuit. The phase-locked loop circuit comprises a phase detector, a proportional charge pump, a decimator, an integral charge pimp, and a voltage-controlled oscillator. The phase detector obtains an phase error information according to a phase difference between a reference signal and a clock signal input to the phase detector. The proportional charge pump coupled to the phase detector generates a first voltage according to the phase error information. The decimator generates a decimated version of the phase error information by a decimation factor of N. The integral charge pump generates a second voltage according to the decimated version of the phase error information. The voltage-controlled oscillator generating the clock signal according to a combination of the first and second voltages. | 08-13-2009 |
20090206941 | CHARGE PUMP-BASED FREQUENCY MODULATOR - A charge pump-based frequency modulator is provided. The charge pump-based frequency modulator comprises an analog phase correction path comprising a varactor and a charge pump. The varactor is coupled to an output of the charge pump-based frequency modulator. The charge pump is coupled to a node between the varactor and the output and receives a signal containing the modulated data. | 08-20-2009 |
20090207901 | DELAY CIRCUIT AND METHOD CAPABLE OF PERFORMING ONLINE CALIBRATION - A delay circuit includes a first reference delay module, a second reference delay module and a first delay module. The first reference delay module delays a reference signal and generates a first reference delayed signal, and the second reference delay module delays the reference signal and generates a second reference delayed signal according to a reference control signal and the first reference delayed signal. The first delay module delays a first input signal and generates a first output signal according to a first control signal and the second reference delayed signal. | 08-20-2009 |
20090284319 | PHASE-LOCKED CIRCUIT EMPLOYING CAPACITANCE MULTIPLICATION - A phase-locked loop circuit. The phase-locked loop circuit comprises a phase detector, a proportional charge pump, a decimator, an integral charge pimp, and a voltage-controlled oscillator. The phase detector obtains an phase error information according to a phase difference between a reference signal and a clock signal input to the phase detector. The proportional charge pump coupled to the phase detector generates a first voltage according to the phase error information. The decimator generates a decimated version of the phase error information by a decimation factor of N. The integral charge pump generates a second voltage according to the decimated version of the phase error information. The voltage-controlled oscillator generating the clock signal according to a combination of the first and second voltages. | 11-19-2009 |
20100019800 | VERNIER PHASE ERROR DETECTION METHOD - A vernier phase error detection method is provided. The method comprises providing a first signal having a first cycle T | 01-28-2010 |
20100208857 | PHASE-LOCKED LOOP CIRCUIT AND RELATED PHASE LOCKING METHOD - A phase-locked loop circuit, including: an operating circuit for detecting a difference between a reference signal and a feedback oscillating signal to generate a detected result, and generating a first control signal according to the detected result, an auxiliary circuit for generating a second control signal that is asynchronous with the first control signal, and a controllable oscillator coupled to the operating circuit and the auxiliary circuit for generating an output oscillating signal according to the first control signal and the second control signal, wherein the feedback oscillating signal is derived from the output oscillating signal. | 08-19-2010 |
20100231310 | MIXED-MODE PLL - A mixed-mode PLL is disclosed. The mixed-mode PLL comprises a digital sigma-delta modulator, a low pass filter, and a digital controlled oscillator. The digital sigma-delta modulator receives a fractional bit signal. The low pass filter is coupled to the digital sigma-delta modulator. The low pass filter receives an output signal of the digital sigma-delta modulator and converts the output signal to an analog control signal. The digital controlled oscillator comprises a varactor dynamically coupled to the low pass filter and receiving the analog control signal. | 09-16-2010 |
20100253401 | SIGNAL PROCESSING CIRCUIT AND SIGNAL PROCESSING METHOD - A signal processing circuit includes: a first operation circuit for receiving a phase component of an input signal, and generating an adjusted phase component and at least one weighting factor according to the phase component of the input signal; a second operation circuit, coupled to the first operation circuit, for receiving the adjusted phase component and converting the adjusted phase component into a frequency component corresponding to the adjusted phase component; a third operation circuit, coupled to the first operation circuit, for receiving an amplitude component of the input signal, and adjusting the amplitude component according to the at least one weighting factor to generate an adjusted amplitude component; and a fourth operation circuit, coupled to the second operation circuit and the third operation circuit, for generating an output signal according to the frequency component and the adjusted amplitude component. | 10-07-2010 |
20100264993 | PLL WITH LOOP BANDWIDTH CALIBRATION CIRCUIT - A phase locked loop (PLL) with a loop bandwidth calibration circuit is provided. The mixed-mode PLL comprises an analog phase correction path, a digital frequency correction path, a calibration current source, and a loop bandwidth calibration circuit. The analog phase correction path comprises a linear phase correction unit (LPCU). The digital frequency correction path comprises a digital integral path circuit. The calibration current source is coupled to the LPCU. The loop bandwidth calibration circuit is coupled to a frequency divider and coupled between the input and output of the PLL. The loop bandwidth calibration circuit operates after the calibration current source injects a calibration current into the LPCU. | 10-21-2010 |
20100277244 | ALL-DIGITAL PHASE-LOCKED LOOP, LOOP BANDWIDTH CALIBRATION METHOD, AND LOOP GAIN CALIBRATION METHOD FOR THE SAME - For decreasing errors within an analog phase-locked loop, an all-digital phase-locked loop (ADPLL) with digital components and digital operations is used. The ADPLL may also be used for direct frequency modulation (DFM). By defining a proportional path gain of an ADPLL by a bandwidth and a reference frequency of the ADPLL, by a TDC gain, a DCO gain, a dividing ratio of a frequency divider, a gain of an amplifier or a combination thereof, the gain of the amplifier may be adjusted so that an optimal loop bandwidth of the ADPLL may be well calibrated. For achieving the aim of entirely digital of the ADPLL, the gains of the TDC and the DCO may be further adjusted in a digital manner. | 11-04-2010 |
20100283549 | PHASE LOCKED LOOP - Phase locked loop circuits capable of increasing an equivalent capacitance thereof to improve stability are provided, in which an integral part comprises a first phase frequency detector providing a phase error signal, a first charge pump circuit generating a control signal according to the phase error signal, a controllable oscillator providing an output clock according to the control signal, and a sampling adjustment unit decreasing the number of times the control signal is updated according to the phase error signal. A proportional part is coupled between the controllable oscillator and a reference clock and operated in a fraction mode. | 11-11-2010 |
20100327984 | PHASE LOCKED LOOP CIRCUITS AND GAIN CALIBRATION METHODS THEREOF - Phase locked loop circuits are provided, in which a phase locked loop module includes a voltage controlled oscillator to generate an oscillation signal with an output frequency according to a control voltage, and a gain calibration module triggers the phase locked loop module to induce a frequency variation characterized by a delta function in the output frequency and calculates a gain of the voltage controlled oscillator according to a phase error caused by the frequency variation in the output frequency. | 12-30-2010 |
20110163790 | SIGNAL PROCESSING CIRCUIT AND SIGNAL PROCESSING METHOD - A signal processing circuit includes: a phase modulating path arranged to adjust a phase component of an input signal to generate an adjusted phase component such that a phase difference of the input signal falls within a target phase difference range; and an amplitude modulating path arranged to exchange a sign of an amplitude component of the input signal corresponding to the phase component to generate an adjusted amplitude component when the phase modulating path adjusts the phase component. | 07-07-2011 |
20110254635 | Oscillating circuit - An oscillating circuit including a digital sigma-delta modulator and a controlled oscillator is disclosed. The digital sigma-delta modulator receives a fractional bit signal to generate a control signal. The controlled oscillator includes a varactor dynamically coupled to receive the control signal. | 10-20-2011 |
20120098580 | TIMING ADJUSTING CIRCUIT - A timing adjusting circuit including a time amplifier and a phase adjusting module is provided. The time amplifier is used for increasing the active pulse-width of a phase control signal, so as to generate an adjusted control signal. Based on the adjusted control signal, the phase adjusting module adjusts the phase of an output signal. The phase of the output signal is associated with the active pulse-width of the phase control signal. | 04-26-2012 |
20120098685 | VOLTAGE CONVERTER - An analog-to-digital converter including a comparator, a control module, a voltage adjusting module, and an evaluating module is provided. The comparator compares an analog input voltage with a feedback voltage and generates a comparison result. Based on the comparison result, the control module generates a control signal. The voltage adjusting module increases or decreases the feedback voltage toward the analog input voltage according to the control signal. The voltage increase amount and decrease amount provided by the voltage adjusting module are corresponding to a first digital value and a second digital value, respectively. The evaluating module generates the first digital value and the second digital value based on the control signal. According to the first digital value and the second digital value, a digital signal corresponding to the analog input voltage is generated. | 04-26-2012 |
20120098686 | VOLTAGE CONVERTER - A voltage converter for converting an analog input signal into a digital signal is provided. The pulse width of the digital signal is relative to the voltage level of the analog input signal. The voltage converter includes a comparator and a feedback module. After comparing the analog input signal and an analog feedback signal, the comparator generates the digital signal. When the analog input signal is higher than the analog feedback signal, the digital signal has a first voltage level. When the analog input signal is lower than the analog feedback signal, the digital signal has a second voltage level, which is different from the first voltage level. Based on the digital signal, the feedback module adjusts the analog feedback signal toward the analog input signal. | 04-26-2012 |
20120099671 | DIGITAL-INTENSIVE SIGNAL PROCESSOR - A digital-intensive signal processor including a signal converting module and a feedback module in a closed timing loop. The signal converting module converts a control signal to an output signal with phase/frequency related to the control signal. The feedback module detects the phase difference between a reference signal and a feedback signal and generates an original control signal based on the phase difference, so as to keep the phases of the output signal and the reference signal related. The feedback signal is associated with the output signal. The control signal includes the original control signal and a signal to be processed. The phase difference, original control signal, control signal, or output signal is a processed signal corresponding to the signal to be processed. | 04-26-2012 |
20130069700 | CIRCUIT AND METHOD FOR CONTROLLING MIXED MODE CONROLLED OSCILLATOR AND CDR CIRCUIT USING THE SAME - A circuit for controlling a mixed mode controlled oscillator. The circuit comprises a charge pump, and a digital loop filter. The charge pump is coupled to the mixed mode controlled oscillator. The charge pump receives an up/down signal and sends a current signal to the mixed mode controlled oscillator. The digital loop filter receives the up/down signal and generates a digital code signal to the mixed mode controlled oscillator. An output frequency of the mixed mode controlled oscillator is controlled by the current signal and the digital code signal. | 03-21-2013 |
20130127501 | SPREAD SPECTRUM CLOCK GENERATORS - Spread spectrum generators and methods are disclosed. In one implementation, a spread spectrum clock generator includes a phase locked loop generating an output clock according to a first clock and a second clock; a delay line coupled between the first clock and the phase locked loop; a modulation unit providing a modulation signal to control the delay line thereby modulating phase of the first clock, such that frequency of the output clock generated by the phase locked loop varies periodically; a scaling unit scaling the modulation signal from the modulation unit according to a scaling ratio, and outputting to the delay line; and a calibration unit generating an output signal for controlling the scaling ratio. | 05-23-2013 |
20130188754 | TRANSMITTER AND FREQUENCY DEVIATION REDUCTION METHOD THEREOF - A transmitter is provided. The transmitter includes a phase/frequency deviation input, a controller and a frequency modulating path. The phase/frequency deviation input receives multiple phase/frequency deviation samples. The controller outputs a modified phase/frequency deviation signal and generates a phase/frequency deviation carry-out signal in response to the phase/frequency deviation samples and a previous time sample of the phase/frequency deviation carry-out signal. The frequency modulating path performs frequency modulation in response to the modified phase/frequency deviation signal and outputs a frequency modulated carrier signal. | 07-25-2013 |
20130234800 | CALIBRATION DEVICE FOR OSCILLATOR AND METHOD THEREOF - A calibration device arranged for calibrating an oscillating frequency of an oscillator includes: a phase locking device arranged to track a first reference clock generated by the oscillator until a feedback clock is phase-aligned with the first reference clock, and then arranged to track a second reference clock generated by the oscillator until a phase difference between the second reference clock and the feedback clock is a static phase difference, wherein the feedback clock is generated by dividing an output oscillating signal of the phase locking device by a divisor; an adjusting circuit arranged to adjust the divisor into an updated divisor to reduce the static phase difference between the second reference clock and the feedback clock; and a calibrating circuit arranged to calibrate the oscillating frequency of the oscillator according to the updated divisor, wherein the second reference clock is generated by varying a control signal of the oscillator. | 09-12-2013 |
20140240053 | SUPPLY VOLTAGE DRIFT INSENSITIVE DIGITALLY CONTROLLED OSCILLATOR AND PHASE LOCKED LOOP CIRCUIT - A digitally controlled oscillator includes a ring oscillator and a first supplementary circuit. The ring oscillator is coupled to a supply voltage and generates a signal oscillated at an oscillating frequency. The oscillating frequency is controlled by a digital code and further varies with a supply voltage drift in a first direction. The first supplementary circuit is coupled to the ring oscillator and facilitates the oscillating frequency to vary with the supply voltage drift in a second direction reverse to the first direction. | 08-28-2014 |