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36 results about "Digital controlled oscillator" patented technology

A digitally controlled oscillator, or DCO, is an oscillator circuit that generates an analog signal, but whose frequency is controlled by a digital control input (as opposed to a voltage controlled oscillator, whose frequency is set by a control voltage ).

Radiation hardening numerical control oscillator, clock data recovery circuit and equipment

The invention discloses an anti-radiation hardening digital controlled oscillator, a clock data recovery circuit and equipment, and the digital controlled oscillator is characterized in that an anti-radiation hardening circuit unit is connected between a digital-to-analog converter (DAC) and a voltage-controlled oscillator (VCO), and comprises a voltage copying unit and a multiplexer; the voltage copying unit is used for copying a control voltage signal output by the digital-to-analog converter DAC, generating a copying voltage signal, sending the copying voltage signal to the multiplexer, and switching the output of the multiplexer from the control voltage signal to the copying voltage signal when the digital-to-analog converter DAC is subjected to single-particle bombardment. The DCO type clock data recovery circuit aims at solving the problem that a traditional DCO type clock data recovery circuit is prone to being affected by single particles when running in a radiation environment, single particle function interruption is generated, and consequently a space task fails, and the radiation hardening capacity of the DCO type clock data recovery circuit running in the radiation environment is improved.
Owner:NAT UNIV OF DEFENSE TECH

Asynchronous control of phase shift using an injection-locked-oscillator-based phase rotator

A circuit includes a phase selector to generate an injection clock signal having an injection phase based on a phase of a digitally controlled oscillator clock signal generated within a phase-locking feedback loop. An injection-locked oscillator (ILO), coupled to an output of the phase selector, generates an ILO clock signal that is convertible to provide a feedback clock signal of the circuit. Logic, coupled between an output of the ILO and the phase selector, to, at each predetermined number of cycles of the DCO clock signal, cause the phase selector to output a phase shift in the injection clock signal that causes the ILO clock signal to comprise a rotated phase, relative to the injection phase, and that prevents a glitch in the injection clock signal.
Owner:NVIDIA CORP

Fractional frequency division frequency synthesizer with output signal phase synchronization and frequency modulation continuous wave functions

The invention discloses a fractional frequency division frequency synthesizer with output signal phase synchronization and frequency modulation continuous wave functions, and the basic structure is a charge pump phase-locked loop. Comprising a phase frequency detector, a first charge pump, a second charge pump, a low-pass filter, a voltage-controlled oscillator, a first buffer, a second buffer, a two-frequency divider chain, an IQ undersampling circuit, a local oscillator generator, a programmable multimode frequency divider, a Delta-Sigma modulator (DSM), a first selector, a second selector, a third selector, a tracking phase accumulator, a numerical control oscillator, an accumulation phase difference register and an atan2 logic circuit. The device comprises a main phase control circuit, a phase adjusting circuit, an enabling control circuit, a waveform generator and a serial peripheral interface. The decimal frequency-division frequency synthesizer can be applied to a general-inductance integrated system, ensures that output signals provided by a plurality of decimal frequency-division frequency synthesizers are consistent in phase in a multi-channel radio frequency transceiving system adopting a multi-chip splicing mode, and can also be applied to the general-inductance integrated system as a sensing signal source; and the speed and the distance of an object can be quickly sensed by the high linearity and the quick chirp capability of an output signal. The decimal frequency division frequency synthesizer is applied to a linear frequency modulation continuous wave radar system, initial phase synchronization can be carried out firstly, then frequency continuous modulation is carried out, and measurement errors can be eliminated. In view of functional similarity of partial modules of the synchronous loop and the FMCW loop, such as a phase frequency detector, a charge pump, a voltage-controlled oscillator and the like, the modules can be shared, so that the power consumption and area cost of the system are remarkably reduced.
Owner:NANJING UNIV OF POSTS & TELECOMM

Numerical control crystal oscillator circuit with low noise and high stability

The invention relates to the field of electronic circuit design, and discloses a numerical control crystal oscillator circuit with low noise and high stability. According to the circuit, a two-stage voltage regulator is adopted to suppress power supply noise, wide-range high-precision frequency regulation is realized through thick and thin capacitor array regulation, oscillation signal quality is ensured through automatic detection feedback and external programming double-loop control, and a special oscillation starting circuit is arranged to accelerate the starting process of a crystal oscillator. Meanwhile, targeted optimization is carried out on a core circuit and layout in the loop, and noise and distortion are further reduced. The digital controlled oscillator can effectively solve the problems that an existing digital controlled oscillator scheme is narrow in frequency modulation range, large in phase noise and the like, the characteristics of low noise, high stability, rapid starting and the like are achieved, an excellent frequency reference is provided for a wireless communication and high-precision timing system, and the digital controlled oscillator has remarkable practical value.
Owner:JIANGSU XINKANG MICROELECTRONICS TECH CO LTD

Voltage-to-frequency switching implementation for increased datacenter quality

Voltage-Frequency domain switching circuits that include multiple stages each configured to receive a throttle code, each of the stages providing a first fast-propagation path for the throttle code to a digitally controlled oscillator, and a frequency locked loop configured to (a) generate a code to the digitally controlled oscillator over a slow path, and (2) disable the fast path to the digitally controlled oscillator upon the code satisfying a match with the throttle code. A second fast-propagation path is configured to propagate a second code to the digitally controlled oscillator.
Owner:NVIDIA CORP

Digital frequency tracking and synchronous sampling control system for resonator gyroscopes

The application discloses a kind of digital frequency tracking and synchronous sampling control system for resonant gyro, including self-excitation oscillation and automatic gain control device, preamplifier circuit and digital signal processor, digital signal processor includes first A / D conversion unit, second A / D conversion unit, frequency error detection unit FD, phase error detection unit PD, digital control oscillator NCO, sampling frequency generator and quadrature demodulation unit, the vibration signal of drive channel is handled after device output to first A / D conversion unit, conversion obtains the vibration signal after conversion, FD obtains frequency difference by frequency error detection, PD obtains phase difference by phase error detection, NCO is adjusted the frequency and phase of sampling frequency generator according to frequency difference and phase difference in real time, until the resonant frequency and phase of drive channel are tracked;The vibration signal of detection channel is handled after circuit output to second A / D conversion unit, obtains the vibration signal after conversion, and quadrature demodulation unit carries out quadrature demodulation and obtains speed signal.
Owner:BEIJING AUTOMATION CONTROL EQUIP INST

Frequency control method and system of digital control oscillator

The invention provides a frequency control method and system for a digital control oscillator, and relates to the technical field of frequency control of the digital control oscillator, and the method comprises the steps: obtaining a current gate period length value of the digital control oscillator, carrying out the gate control counting of an output clock of the digital control oscillator based on the current gate period length value, and obtaining an in-gate counting sequence, calculating a noise estimator based on the in-gate counting sequence, determining a target gate period length value based on the noise estimator, determining an instantaneous frequency ratio based on the target gate period length value, calculating a smoothing factor based on the noise estimator and the target gate period length value, and smoothing the instantaneous frequency ratio based on the smoothing factor to obtain a smooth frequency ratio; the target frequency tuning word is determined based on the smooth frequency ratio, the output frequency of the digital control oscillator is adjusted based on the target frequency tuning word, and the method has the effects of improving the dynamic performance, the steady-state precision and the environment adaptive capacity of frequency control of the digital control oscillator.
Owner:BEIJING GUANGSHI UNLIMITED TECH CO LTD +1

An anti-radiation hardened numerically controlled oscillator, clock data recovery circuit, and device

The application discloses an anti-radiation reinforced digital controlled oscillator, a clock data recovery circuit and equipment. The anti-radiation reinforced digital controlled oscillator is connected with an anti-radiation reinforced circuit unit between a digital-analog converter (DAC) and a voltage controlled oscillator (VCO). The anti-radiation reinforced circuit unit comprises a voltage replication unit and a multiplexer. The voltage replication unit is used for replicating a control voltage signal output by the digital-analog converter (DAC) and generating a replication voltage signal to be sent to the multiplexer. When the digital-analog converter (DAC) is subjected to single particle bombardment, the output of the multiplexer is switched from the control voltage signal to the replication voltage signal. The application aims to solve the problem that the traditional DCO type clock data recovery circuit is easily affected by single particles when running in a radiation environment, resulting in single particle function interruption and causing space task failure. The anti-radiation reinforced ability of the DCO type clock data recovery circuit when running in a radiation environment is improved.
Owner:NAT UNIV OF DEFENSE TECH

Improved abspd clock recovery method at half baud rate sampling

The application relates to an improved ABSPD clock recovery method under single baud rate sampling, clock synchronization of transceiving end signals is realized through a full-digital type clock recovery loop, a timing error detector is used to replace numerical multiplication operation with symbol judgment and shift operation when calculating timing error e; after the timing error e is calculated by the timing error detector, the timing error e is input into a loop filter to remove noise and control words W are obtained; then the control words W are used to control a digital controlled oscillator, fractional interval mu k is calculated from the output NCO of the digital controlled oscillator and the control words W k The integer mark m k of the symbol and the calculated fractional interval mu k The received signal is interpolated in an interpolation filter, so that timing correct data are calculated. The application realizes ABSPD clock recovery under single baud rate sampling without multiplication operation, and significantly reduces the complexity of the whole clock recovery loop.
Owner:SUN YAT SEN UNIV

A quantum measurement and control system based on RFSOC

The present invention discloses a quantum measurement and control system based on RFSOC, specifically relating to the field of RFSOC control. The system includes an RFSOC chip, which integrates: a digital-to-analog conversion module, including eight 6.5GS / s digital-to-analog converters; an analog-to-digital conversion module, including eight 4GS / s analog-to-digital converters; an RF input module, connected to the digital-to-analog conversion module, including an RF input channel and a first signal conditioning circuit; and an RF output module, connected to the analog-to-digital conversion module, including an RF output channel and a second signal conditioning circuit. The digital-to-analog converter and the analog-to-digital converter are respectively connected to configurable IQ digital up / down conversion, a digitally controlled oscillator, a gain matrix, and decimation / interpolation filters. This invention fully leverages the advantages of the highly integrated RFSOC FPGA. It can be easily integrated into logic via an AXI interface. Furthermore, the present invention adds signal conditioning circuits to the DAC output and ADC output to achieve fine power adjustment.
Owner:成都中微达信科技有限公司

Feed baseband rapid dynamic frequency offset compensation method and device

The invention discloses a feed baseband rapid dynamic frequency offset compensation method and device. The device comprises a baseband unit and a radio remote unit. The baseband unit is responsible for frequency offset estimation and compensation amount calculation, the remote radio unit is composed of a CPU, an FPGA and an RFIC, the FPGA is used for digital intermediate frequency processing and a forward transmission interface, and the CPU completes parameter updating of an uplink numerical control oscillator and a downlink numerical control oscillator according to compensation information and achieves frequency offset correction of intermediate frequency signals so as to complete frequency offset compensation; then, the CPU controls the FPGA to send a real-time response message, and feeds back a compensation execution completion state to the baseband unit to form closed-loop control; according to the method, the special control frame is constructed in the eCRPI interface, so that the real-time dynamic compensation of the satellite feed baseband frequency offset is realized, and the stability and the high reliability of a satellite-ground link in a high-speed moving environment are ensured.
Owner:NANJING DIANGE INFORMATION TECH CO LTD

Digital baseband and qubit manipulator for low-temperature qubit manipulation

The present invention discloses a digital baseband and a qubit manipulator for low-temperature qubit manipulation. The digital baseband combines DDS and AWG modes, utilizing the DDS mode to achieve efficient frequency, phase, and amplitude adjustment, and the AWG mode to provide arbitrary waveform generation capabilities, thereby meeting the requirements of qubits when performing complex operations. Furthermore, since both the X-channel DDS module and the Y-channel DDS module of the XY driver have a digitally controlled oscillator, they can simultaneously generate independent digital intermediate frequency pulses, achieving frequency division multiplexing. This allows for direct output of simple sin waves, as well as reading waveform pulse data from the XY channel memory to output corresponding modulated pulse waveform data according to different requirements. Therefore, the present invention not only enables efficient and flexible qubit manipulation, but also enables multiple signals to share the same communication channel, optimizing channel utilization and thereby improving the overall transmission efficiency of the digital baseband.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

Asynchronous control of phase shift using an injection-locked-oscillator-based phase rotator

A circuit includes a phase selector to generate an injection clock signal having an injection phase based on a phase of a digitally controlled oscillator clock signal generated within a phase-locking feedback loop. An injection-locked oscillator (ILO), coupled to an output of the phase selector, generates an ILO clock signal that is convertible to provide a feedback clock signal of the circuit. Logic, coupled between an output of the ILO and the phase selector, to, at each predetermined number of cycles of the DCO clock signal, cause the phase selector to output a phase shift in the injection clock signal that causes the ILO clock signal to comprise a rotated phase, relative to the injection phase, and that prevents a glitch in the injection clock signal.
Owner:NVIDIA CORP

Signal generation in and / or for radio

A method includes generating an output clock in a digitally controlled oscillator, dividing the output clock to generate a divided clock, generating a feedback clock based on the divided clock, generating an error signal based on a phase difference between a reference clock and the feedback clock, and controlling the digitally controlled oscillator based on the error signal, wherein generating the feedback clock includes connecting a first current source to a capacitor according to a fixed delay with respect to the divided clock, connecting a second current source to the capacitor prior to the fixed delay according to a first programmable select parameter, connecting a third current source to the capacitor prior to the fixed delay according to a second programmable select parameter, and generating the feedback clock based on a voltage of the capacitor after connecting the first, second, and third current sources to the capacitor.
Owner:INFINEON TECHNOLOGIES AMERICAS CORP

Digital phase-locked loop system and PLL output frequency modulation range real-time adjusting method thereof

The invention discloses a digital phase-locked loop system and a PLL output frequency modulation range real-time adjusting method thereof. The digital phase-locked loop system digitally controls an oscillator. The digital control oscillator comprises a plurality of groups of macro cells, and each group of macro cells comprises at least one macro cell; and each group of macro units is used for being switched on or switched off according to a configurable control signal input by a user, so that the switched-on macro units determine a PLL output frequency modulation range, and the PLL output frequency modulation range is adjusted according to an adjusting instruction input by the user. The effective frequency modulation range of the digital phase-locked loop system can be changed on the premise that a hardware circuit is not changed, so that the digital phase-locked loop system can flexibly adapt to various application scenes with huge differences, and the maximum application flexibility is obtained while the advantages of a single hardware design are kept.
Owner:PRIMARIUS TECH CO LTD

A digitally controlled oscillator calibration system

The embodiment of the present specification discloses a digitally controlled oscillator calibration system. The system comprises a signal detection component, a phase discriminator, a digitally controlled oscillator gain module, a digital filter and a digitally controlled oscillator, wherein the digitally controlled oscillator is connected with the signal detection component, the signal detection component is connected with the phase discriminator, the phase discriminator is connected with the digitally controlled oscillator gain module, the digitally controlled oscillator gain module is connected with the digital filter, and the digital filter is connected with the digitally controlled oscillator. The embodiment of the present specification can not directly adjust the initial control word, but additionally generate a tuning control word for adjustment, so that the adjustment process is not affected by the size of the initial control word, and the adjustment can be performed with smaller code values, thereby improving the calibration accuracy.
Owner:ZHEJIANG SAISI ELECTRONICAL TECHNOLOGY CO LTD

Digitally controlled oscillator for synthesizer module, synthesizer module, synthesizer and electronic audio signal generation method

ActiveCN114041266BElectrophonic musical instrumentsPulse automatic controlHemt circuitsDigital controlled oscillator
The present invention provides a digitally controlled oscillator (100), a synthesizer module (200), a synthesizer (300), and a method for generating an electronic audio signal. The oscillator (100) includes a digital processing device (10) capable of generating a first pulse wave at a first output terminal (PulseUp) of the processing device (10), wherein the first pulse wave includes pulses with at least two different frequencies. The oscillator (100) further includes a summing circuit (30) and a linear wave shaper (20). The output terminal (PulseUp) of the processing device (10) is connected to the summing circuit (30), and the summing circuit generates a total signal based on at least the first pulse wave. The total signal is fed to the linear wave shaper (20), and the linear wave shaper can generate an output signal at the output terminal (OUT) of the oscillator (100) by modifying the total signal.
Owner:SUPERCRITICAL OY

Frequency hopping transmitting device and frequency hopping communication system formed by same

The utility model provides a frequency hopping transmitting device and a frequency hopping communication system formed by the same, and relates to the technical field of radio communication, the frequency hopping transmitting device comprises a frequency hopping local oscillator unit, an L frequency band transmitting channel and a C frequency band transmitting channel, the frequency hopping local oscillator unit comprises a radio frequency transmitter, a radio frequency balun transformer, a first low-pass filter and a second low-pass filter, the radio frequency transmitter is composed of a digital control oscillator, an L-band local oscillator signal and a C-band local oscillator signal are respectively output to a first low-pass filter and a second low-pass filter through two radio frequency balun transformers, and the first low-pass filter transmits the L-band local oscillator signal to an L-band transmitting channel. And the second low-pass filter transmits the C-band local oscillator signal to the C-band transmitting channel. The frequency hopping local oscillator unit provided by the utility model takes the digital control oscillator as a core, has the advantages of small volume and low power consumption, and can greatly reduce the size of a filter without influencing the performance of the filter.
Owner:GUANGZHOU HAIGE COMMUNICATION GROUP INCORPORATED COMPANY +1

An ASK 100% modulation communication system and method applied to passive NFC tags

The application discloses an ASK 100% modulation communication system and method applied to a passive NFC tag. The application generates a recovered clock signal by introducing a high-precision digital control oscillator circuit, uses a carrier clock signal for timing control in a signal receiving process of the NFC tag, and switches to the recovered clock signal for timing control in a signal sending process, so that the passive NFC tag has a stable clock source during clock loss of ASK 100% modulation, and the normal work of a digital circuit can be ensured. Meanwhile, the application also introduces a digital clock calibration circuit, has relatively small area and power consumption under the premise of ensuring calibration frequency, and is more suitable for the development trend and requirement of low power consumption and low cost of the passive NFC tag. The application realizes the communication of the passive NFC tag with a PCD by using ASK 100% for load modulation, greatly improves the anti-interference ability of a signal, can optimize the requirement for a minimum antenna coupling coefficient k, optimizes the geometric alignment requirement of an antenna, and improves the long-distance communication ability of the tag.
Owner:SOUTH CHINA NORMAL UNIV

A High-Order QAM Signal Demodulation Carrier Synchronization Design Method Based on Two-Level Loop Filtering

This invention discloses a carrier synchronization design method for high-order QAM signal demodulation based on a two-stage loop filter, relating to the field of signal processing. It considers both steady-state phase difference and acquisition bandwidth for carrier synchronization, covering various application scenarios and providing good demodulation performance. This invention is implemented through the following technical solution: Loop one mainly includes a carrier compensator, a digital frequency discriminator, a digitally controlled oscillator, a first-stage digital loop filter, and a frequency lock detector; Loop two mainly includes a carrier compensator, a digital phase discriminator, a digitally controlled oscillator, a second-stage digital loop filter, and a phase lock detector. After the two loops are connected in series, the first-stage loop synchronously compensates for larger frequency offsets of the signal, while the second-stage loop synchronously compensates for smaller residual frequency and phase offsets. The lock detector monitors the design, achieving carrier synchronization for high-order QAM signal demodulation.
Owner:10TH RES INST OF CETC

Digitally controlled oscillator, signal generation method and electronic device

ActiveCN115328266BEnergy efficient computingDigital function generatorsComputer hardwareDigital controlled oscillator
The application provides a digital control oscillator for a reconfigurable computing array, comprising a configuration module connected with a Cordic operation array, an output control module and an output cache module, and used for setting configuration information of the Cordic operation array, configuration information of the output control module and configuration information of the output cache module; the Cordic operation array is connected with the output control module, and used for generating a down-converted signal according to the configuration information of the Cordic operation array, and sending the down-converted signal to the output control module; the output control module is connected with the output cache module, and used for outputting the down-converted signal to the output cache module according to the configuration information of the output control module; and the output cache module is used for outputting a quadrature signal based on the down-converted signal according to the configuration information of the output cache module. The application further provides a signal generation method and electronic equipment, which can improve the NCO performance and reduce the NCO energy consumption.
Owner:TSINGHUA UNIVERSITY +1

Methods and apparatus of charge-sharing locking with digital controlled oscillators

PendingUS20250392316A1Pulse automatic controlDigital technique networkSoftware engineeringDigital controlled oscillator
A method includes causing a digital controlled oscillator to oscillate in a phase locked loop having a first closed loop transfer function, and changing the phase locked loop having the first closed loop transfer function to a phase locked loop having a second closed loop transfer function. The method also includes starting a charge-sharing locking process to correct phase errors in the digital controlled oscillator while the digital controlled oscillator oscillates in the phase locked loop having the second closed loop transfer function.
Owner:TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

Multi-band finely adjustable wide-tuning range digitally controlled oscillators, phase-locked loops and chips

This invention relates to a multi-band finely tunable, wide-tuning-range numerically controlled oscillator, phase-locked loop, and chip. The numerically controlled oscillator includes n differential operational amplifier delay units, 2n array tuning circuits, and one digital-to-analog converter; the n differential operational amplifier delay units are cascaded, and the output V at the end of the cascade is... out +、V out - and the input V at the cascade start end in +、V in The positive and negative terminals of the circuit are reversed to form a ring structure; any one differential operational amplifier delay unit is connected to two array tuning circuits; a digital-to-analog converter is used to provide control voltage to the array tuning circuits. This invention significantly reduces oscillator phase noise through the combination of a tail current source and capacitor filtering, while simultaneously enabling a wide tuning range by adjusting the operating state of the array tuning circuits. The digital-to-analog converter achieves 256-bit fine-level voltage control, allowing for significantly precise operation of the output frequency, thus meeting the higher resolution requirements of a fully digital phase-locked loop.
Owner:ANHUI UNIV

Low-power-consumption numerical control oscillator

PendingCN121864021AOscillations generatorsDigital tuningCapacitance
The invention provides a low-power-consumption numerically-controlled oscillator, relates to the technical field of integrated circuits, and comprises a resonant cavity module used for generating a high-frequency resonant signal based on a resonator; the input end of the complementary cross-coupled oscillation module is connected with the resonant cavity module, and the complementary cross-coupled oscillation module is used for receiving high-frequency resonant signals and generating continuous oscillation; a capacitor array of the segmented numerical control capacitor tuning module is connected in parallel to two ends of the resonant cavity module and is used for receiving external numerical control signals and changing equivalent capacitance of a resonant network, so that wide-range and high-precision digital tuning is carried out on oscillation frequency; the parasitic oscillation suppression module is integrated in an internal feedback path of the complementary cross-coupled oscillation module and is used for suppressing direct-current positive feedback and attenuating low-frequency loop gain so as to eliminate direct-current locking and low-frequency parasitic oscillation; the input end of the output buffer module is connected with the output node of the complementary cross-coupling oscillation module, and the output buffer module is used for shaping and driving the oscillation signal and then outputting the signal. In the mode, wide tuning, ultra-low power consumption, high stability and high-precision tuning are realized, meanwhile, the phase noise performance and the mass production feasibility are improved, and the strict requirements of the battery-free Internet of Things node are met.
Owner:SHANGHAI QUANRAY ELECTRONICS

A method and device for fast dynamic frequency offset compensation of a feeding baseband

The application discloses a kind of feeding baseband fast dynamic frequency offset compensation method and device, including baseband unit and radio frequency remote unit;Baseband unit is responsible for frequency offset estimation and compensation quantity calculation, radio frequency remote unit is composed of CPU, FPGA and RFIC, the FPGA is used for digital intermediate frequency processing and front interface, CPU completes the parameter update of uplink digital controlled oscillator and downlink digital controlled oscillator according to compensation information, the frequency offset correction of intermediate frequency signal is realized, to complete frequency offset compensation;Subsequently, the CPU controls FPGA to send real-time response message, and the state of compensation execution completion is fed back to baseband unit, to form closed loop control;The application realizes the real-time dynamic compensation of satellite feeding baseband frequency offset by constructing special control frame in eCRPI interface, ensures the stability and high reliability of satellite-ground link under high-speed mobile environment.
Owner:NANJING DIANGE INFORMATION TECH CO LTD

Digital control oscillator based on harmonic impedance tuning

The invention discloses a digitally controlled oscillator based on harmonic impedance tuning. The digitally controlled oscillator comprises a first MOS (Metal Oxide Semiconductor) tube, a second MOS tube, a transformer with a center tap, a coarse tuning capacitor bank, a middle tuning capacitor bank and a harmonic impedance tuning network, a source electrode of the first MOS tube is connected with a source electrode of the second MOS tube, and a source electrode common point is grounded through a harmonic impedance tuning network; the grid electrode of the first MOS tube is connected with the drain electrode of the second MOS tube, and the drain electrode of the first MOS tube is connected with the grid electrode of the second MOS tube; a center tap of the transformer is connected with a VDD power supply; two ends of a primary coil of the transformer are respectively connected with a drain electrode of the first MOS tube and a drain electrode of the second MOS tube; the first end of the middle tuning capacitor bank is connected with the first end of the secondary coil of the transformer, and the second end of the middle tuning capacitor bank is connected to the second end of the secondary coil of the transformer. The invention has the advantages of high resolution and monotonous frequency tuning, and can optimize the phase noise performance.
Owner:THE CHINESE UNIV OF HONG KONG (SHENZHEN)

Enhanced hybrid clock

A subordinate clock includes a first servo loop, a second servo loop, and a third servo loop, each include a respective digitally controlled oscillator (DCO). The first DCO receives (i) a first error signal that is associated with a physical layer reference signal and (ii) an oscillating signal and outputs a physical layer clock signal. The second DCO receives (i) a second error signal associated with the physical layer clock signal and (ii) the oscillating signal and outputs an intermediate clock signal. The third DCO receives (i) a third error signal associated with a grandmaster reference signal generated by a grandmaster clock and (ii) the intermediate clock signal and outputs a final clock signal with an average frequency that is generally equal to an average frequency of the grandmaster reference signal.
Owner:VIAVI SOLUTIONS INC(US)

Low-jitter two-stage LC-ring hybrid architecture phase-locked loop suitable for multi-channel SerDes

The invention relates to the technical field of control circuits, and discloses a low-jitter two-stage LC-ring hybrid architecture phase-locked loop suitable for multi-channel SerDes, which comprises a frequency locking loop which comprises a time-to-digital converter, a digital control oscillator and a frequency control module, the output end of the digital control oscillator is connected to the first control end of the digital control oscillator through the time-to-digital converter and the frequency control module in sequence, and the digital control oscillator is used for achieving rapid coarse tuning of the frequency. According to the invention, a two-stage control architecture with separated frequency locking and phase locking is adopted, an LC-ring mixed DCO structure is combined, the ring oscillator is utilized to quickly converge the frequency in a frequency capture stage, and the LC oscillator is switched to provide a low-phase noise clock in a phase locking stage, so that the frequency of the low-phase noise clock is reduced. The contradiction between the locking speed and the output jitter of the traditional phase-locked loop in the high-speed SerDes application is effectively solved, and the clock generation efficiency and quality are remarkably improved.
Owner:CHONGQING UNIV

Digital fractional-n phase locked loop

The invention relates to a digital fractional-N phase-locked loop (PLL) (1) comprising:-a forward path comprising a phase discriminator (4), a digital loop filter (3), a digitally controlled oscillator (2); a feedback path comprising feedback elements (5, 6) wherein the phase discriminator output of the phase discriminator (4) is connected to the loop filter input of the digital loop filter (3) for providing an unfiltered control signal (Suf) and the loop filter output of the digital loop filter (3) is connected to the oscillator input of the digitally controlled oscillator (2) for providing a filtered control signal (Sf), wherein the unfiltered control signal (Suf) and the filtered control signal (Sf) each contain a periodic error signal having mutually different amplitudes; -a digital-to-time converter (7) arranged in a forward or feedback path and connected with a converter output to a phase discriminator input of the phase discriminator (4); -a spurious compensation unit (10) arranged with two inputs and an output, where a first input is arranged to receive an unfiltered control signal (Suf) and a second input is configured to receive a filtered control signal (Sf), where the spurious compensation unit (10) is arranged to determine a compensation signal (Sscop) along fractional phase instances of operation of the digital fractional-N PLL (1), and where the spurious compensation unit (10) is arranged to determine a compensation signal (Sscop) along fractional phase instances of operation of the digital fractional-N PLL (1). The spurious compensation unit (10) is further arranged to output the compensation signal (Sscop) to a converter input of the digital-to-time converter (7), or wherein the spurious compensation unit (10) is further arranged to inject the compensation signal (Sscop) into the unfiltered control signal (Suf) for compensating the periodic error signal.
Owner:ETH ZURICH