CMOS analog and mixed-signal phase-locked loops(PLL)are widely used in varies of the system-on-chips(SoC)as the clock generator or frequency synthesizer.This paper presents an overview of the AMS-PLL,including:1)a bri...CMOS analog and mixed-signal phase-locked loops(PLL)are widely used in varies of the system-on-chips(SoC)as the clock generator or frequency synthesizer.This paper presents an overview of the AMS-PLL,including:1)a brief introduction of the basics of the charge-pump based PLL,which is the most widely used AMS-PLL architecture due to its simplicity and robustness;2)a summary of the design issues of the basic CPPLL architecture;3)a systematic introduction of the techniques for the performance enhancement of the CPPLL;4)a brief overview of ultra-low-jitter AMS-PLL architectures which can achieve lower jitter(<100 fs)with lower power consumption compared with the CPPLL,including the injection-locked PLL(ILPLL),subsampling(SSPLL)and sampling PLL(SPLL);5)a discussion about the consideration of the AMS-PLL architecture selection,which could help designers meet their performance requirements.展开更多
We propose a novel hybrid phase-locked loop (PLL) architecture for overcoming the trade-off between fast locking time and low spur. To reduce the settling time and meanwhile suppress the reference spurs, we employ a...We propose a novel hybrid phase-locked loop (PLL) architecture for overcoming the trade-off between fast locking time and low spur. To reduce the settling time and meanwhile suppress the reference spurs, we employ a wide-band single-path PLL and a narrow-band dual-path PLL in a transient state and a steady state, respectively, by changing the loop bandwidth according to the gain of voltage controlled oscillator (VCO) and the resister of the loop filter. The hybrid PLL is implemented in a 0.18-μm complementary metal oxide semiconductor (CMOS) process with a total die area of 1.4×0.46 mm2. The measured results exhibit a reference spur level of lower than -73 dB with a reference frequency of 10 MHz and a settling time of 20 μs with 40 MHz frequency jump at 2 GHz. The total power consumption of the hybrid PLL is less than 27 mW with a supply voltage of 1.8 V.展开更多
Voltage source converter based high-voltage direct current(VSC-HVDC)transmission technology has been extensively employed in power systems with a high penetration of renewable energy resources.However,connecting a vol...Voltage source converter based high-voltage direct current(VSC-HVDC)transmission technology has been extensively employed in power systems with a high penetration of renewable energy resources.However,connecting a voltage source converter(VSC)to an AC weak grid may cause the converter system to become unstable.In this paper,a phase-shift phaselocked loop(PS-PLL)is proposed wherein a back electromotive force(BEMF)observer is added to the conventional phaselocked loop(PLL).The BEMF observer is used to observe the voltage of the infinite grid in the stationaryαβframe,which avoids the problem of inaccurate observations of the grid voltage in the dq frame that are caused by the output phase angle errors of the PLL.The VSC using the PS-PLL can operate as if it is facing a strong grid,thus enhancing the stability of the VSC-HVDC system.The proposed PS-PLL only needs to be properly modified on the basis of a traditional PLL,which makes it easy to implement.In addition,because it is difficult to obtain the exact impedance of the grid,the influence of shortcircuit ratio(SCR)estimation errors on the performance of the PS-PLL is also studied.The effectiveness of the proposed PSPLL is verified by the small-signal stability analysis and timedomain simulation.展开更多
This article overviews the design considerations and state-of-the-art of the ring voltage-controlled oscillator(VCO)-based phase-locked loops(PLLs)for clock generation in different applications.Partic-ularly,the objec...This article overviews the design considerations and state-of-the-art of the ring voltage-controlled oscillator(VCO)-based phase-locked loops(PLLs)for clock generation in different applications.Partic-ularly,the objective of the current work is to evaluate the required PLL performance among the fundamental metrics of power,jitter and area.An in-depth treatment of the mainstream PLL architectures and the associated design techniques enables them to be compared analyt-ically and benchmarked with respect to their figure-of-merit(FoM).The paper also summarizes the key concerns on the selection of dif-ferent circuit techniques to optimize the clock performance under dif-ferent scenarios.展开更多
In order to solve problems in high dynamic environment, a frequency-locked loop (FLL) assisted phase-locked loop (PLL) is put forward for carrier tracking. On the basis of the analysis of discriminators, the total...In order to solve problems in high dynamic environment, a frequency-locked loop (FLL) assisted phase-locked loop (PLL) is put forward for carrier tracking. On the basis of the analysis of discriminators, the total phase error of the tracking loop is analyzed and a general error expression is derived. By using linearization and Jaffe-Rechtin coefficients, the performance of a special first order FLL-assisted second order PLL is analyzed to get a closed expression. Analysis results and simula- tions show that there exist an optimal FLL loop bandwidth and a optimal PLL loop bandwidth which can make the phase jitter much less than that when the PLL is used alone.展开更多
An S-band frequency synthesizer for a stepped-frequency radar is presented. This frequen- cy synthesizer is based on a direct digital synthesizer ( DDS ) -driven wideband phase-locked loop (PLL) architecture which...An S-band frequency synthesizer for a stepped-frequency radar is presented. This frequen- cy synthesizer is based on a direct digital synthesizer ( DDS ) -driven wideband phase-locked loop (PLL) architecture which can achieve low spurious noise and rapid frequency hopping simultaneous- ly. The mechanism of introducing high level spurs by the images of DDS digital to analog convertor (DAC) output is analyzed. A novel DDS frequency planning method is proposed to ensure low col- ored noise within the entire bandwidth. The designed output frequency range is 3. 765 -4. 085 GHz, and the step size is 5 MHz with frequency agility of less than 1 μs. Measured results demonstrate that the average spurious free dynamic range (SFDR) is about 64 dBc in a 320 MHz bandwidth.展开更多
This paper proposes a novel Gm-C loop filter instead of a conventional passive loop filter used in a phase-locked loop. The innovative advantage of the proposed architecture is tunable loop filter bandwidth and hence ...This paper proposes a novel Gm-C loop filter instead of a conventional passive loop filter used in a phase-locked loop. The innovative advantage of the proposed architecture is tunable loop filter bandwidth and hence the process variations of passive elements of resistance R and capacitance C can be overcome and the chip area is greatly reduced. Furthermore, the MASH 1-1-1 sigma-delta (ZA) modulator is adopted for performing the fractional division number and hence improves the phase noise as well. Measured results show that the locked phase noise is -114.1 dBc/Hz with lower Gm-C bandwidth and -111.7 dBm/C with higher Gm-C bandwidth at 1 MHz offset from carrier of 5.68 GHz. Including pads and built-in Gm-C filter, the chip area of the proposed frequency synthesizer is 1.06 mm2. The output power is -8.69 dBm at 5.68 CHz and consumes 56 mW with an off-chip buffer from 1.8-V supply voltage.展开更多
In renewable power generation systems,ensuring the synchronization of the inverter and the power grid is crucial for the stable operation of grid-connected inverters.Nowadays,the phase-locked loop(PLL)technology has b...In renewable power generation systems,ensuring the synchronization of the inverter and the power grid is crucial for the stable operation of grid-connected inverters.Nowadays,the phase-locked loop(PLL)technology has become a widely used grid synchronization method because of its simple implementation and robustness under various grid conditions.Even though a lot of PLLs have been proposed,an overview and comparative analysis of multiple PLLs can be helpful for practical applications.In addition,the weak grid condition is a great challenge for the system.Therefore,this study first presents an overview of the existing PLLs together with their general structures and basic working principles.Depending on the implementation of the phase detector,the PLL can be divided into three categories:power-based PLL(pPLL),orthogonal-signalgenerator-based PLL(OSG-PLL)and adaptive-filter-based PLL(AF-PLL).Then,from the above classification,seven typical single-phase PLLs are selected for further study.Finally,some test results are given,and a comprehensive evaluation of the selected PLLs under different grid conditions is conducted.展开更多
A high-speed dual-modulus divide-by-32/33 prescaler has been developed using 0.25 μm CMOS technology. The source-coupled logic (SCL) structure is used to reduce the switching noise and to ameliorate the power-speed t...A high-speed dual-modulus divide-by-32/33 prescaler has been developed using 0.25 μm CMOS technology. The source-coupled logic (SCL) structure is used to reduce the switching noise and to ameliorate the power-speed tradeoff. The proposed prescaler can operate at high frequency with a low-power consumption. Based on the 2.5 V, 0.25 μm CMOS model, simulation results indicate that the maximum input frequency of the prescaler is up to 3.2 GHz. Running at 2.5 V, the circuit consumes only 4.6 mA at an input frequency 2.5 GHz.展开更多
As the proportion of converter-interfaced renewable energy resources in the power system is increasing,the strength of the power grid at the connection point of wind turbine generators(WTGs)is gradually weakening.Exis...As the proportion of converter-interfaced renewable energy resources in the power system is increasing,the strength of the power grid at the connection point of wind turbine generators(WTGs)is gradually weakening.Existing research has shown that when connected with the weak grid,the stability of the traditional grid-following controlled converters will deteriorate,and they are prone to unstable phenomena such as oscillation.Due to the limitations of linear analysis that cannot sufficiently capture the stability phenomena,transient stability must be investigated.So far,standalone time-domain simulations or analytical Lyapunov stability criteria have been used to investigate transient stability.However,the time-domain simulations have proven to be computationally too heavy,while analytical methods are difficult to formulate for larger systems,require many modelling assumptions,and are often conservative in estimating the stability boundary.This paper proposes and demonstrates an innovative approach to estimating the transient stability boundary via combining the linear Lyapunov function and the reverse-time trajectory technique.The proposed methodology eliminates the need of time-consuming simulations and the conservative nature of Lyapunov functions.This study brings out the clear distinction between the stability boundaries with different post-fault active current ramp rate controls.At the same time,it provides a new perspective on critical clearing time for wind turbine systems.The stability boundary is verified using time-domain simulation studies.展开更多
The analysis of stability and numerical simulation of Costas loop circuits for the high-frequency signals is a challenging task. The problem lies in the fact that it is necessary to observe very fast time scale of inp...The analysis of stability and numerical simulation of Costas loop circuits for the high-frequency signals is a challenging task. The problem lies in the fact that it is necessary to observe very fast time scale of input signals and slow time scale of signal s phases simultaneously. To overcome this difficulty, it is possible to follow the classical ideas of Gardner and Viterbi to construct a mathematical model of Costas loop, in which only slow time change of signal s phases and frequencies is considered. Such an construction, in turn,requires the computation of phase detector characteristic, depending on the waveforms of the considered signals. In this paper, the problems of nonlinear analysis of Costas loops and the approaches to the simulation of the classical Costas loop, the quadrature phase shift keying(QPSK) Costas loop, and the two-phase Costas loop are discussed. The analytical method for the computation of phase detector characteristics of Costas loops is described.展开更多
A novel method based on the analysis of instantaneous phase is proposed to extract the jitter on phase-locked loops output clock. The method utilizes the Hilbert transform to extend the real signal of PLLs output into...A novel method based on the analysis of instantaneous phase is proposed to extract the jitter on phase-locked loops output clock. The method utilizes the Hilbert transform to extend the real signal of PLLs output into an analytic signal, and the implementation of Hilbert transform is based on the Fourier transform windowed with Hamming window. Then, the jitter of clock is extracted from the instantaneous phase of analytic signal. The experimental results of simulations validate that the proposed method can effectively extract the jitter on PLL clock, and it has better performance by comparing the sinusoidal jitter extraction results with the other methods.展开更多
Phase-locked loops (PLLs) are essential wherever a local event is synchronized with a periodic external event. They are utilized as on-chip clock frequency generators to synthesize a low skew and higher internal frequ...Phase-locked loops (PLLs) are essential wherever a local event is synchronized with a periodic external event. They are utilized as on-chip clock frequency generators to synthesize a low skew and higher internal frequency clock from an external lower frequency signal and its characterization and measurement have recently been calling for more and more attention. In this paper, a built-in on-chip circuit for measuring jitter of PLL based on a duty cycle modulation vernier delay line is proposed and demonstrated. The circuit employs two delay lines to measure the timing difference and transform the difference signal into digital words. The vernier lines are composed of delay cells whose duty cycle can be adjusted by a feedback voltage. It enables the circuit to have a self calibration capability which eliminates the mismatch problem caused by the process variation.展开更多
基金supported by the Pioneer Hundred Talents Program,Chinese Academy of Sciences.
文摘CMOS analog and mixed-signal phase-locked loops(PLL)are widely used in varies of the system-on-chips(SoC)as the clock generator or frequency synthesizer.This paper presents an overview of the AMS-PLL,including:1)a brief introduction of the basics of the charge-pump based PLL,which is the most widely used AMS-PLL architecture due to its simplicity and robustness;2)a summary of the design issues of the basic CPPLL architecture;3)a systematic introduction of the techniques for the performance enhancement of the CPPLL;4)a brief overview of ultra-low-jitter AMS-PLL architectures which can achieve lower jitter(<100 fs)with lower power consumption compared with the CPPLL,including the injection-locked PLL(ILPLL),subsampling(SSPLL)and sampling PLL(SPLL);5)a discussion about the consideration of the AMS-PLL architecture selection,which could help designers meet their performance requirements.
基金supported by the National Natural Science Foundation of China(Grant No.61307128)the National Basic Research Program of China(GrantNo.2010CB327505)+1 种基金the Specialized Research Found for the Doctoral Program of Higher Education of China(Grant No.20131101120027)the Basic Research Foundation of Beijing Institute of Technology of China(Grant No.20120542015)
文摘We propose a novel hybrid phase-locked loop (PLL) architecture for overcoming the trade-off between fast locking time and low spur. To reduce the settling time and meanwhile suppress the reference spurs, we employ a wide-band single-path PLL and a narrow-band dual-path PLL in a transient state and a steady state, respectively, by changing the loop bandwidth according to the gain of voltage controlled oscillator (VCO) and the resister of the loop filter. The hybrid PLL is implemented in a 0.18-μm complementary metal oxide semiconductor (CMOS) process with a total die area of 1.4×0.46 mm2. The measured results exhibit a reference spur level of lower than -73 dB with a reference frequency of 10 MHz and a settling time of 20 μs with 40 MHz frequency jump at 2 GHz. The total power consumption of the hybrid PLL is less than 27 mW with a supply voltage of 1.8 V.
基金supported by the National Natural Science Foundation of China(No.51677142)the National Key R&D Program of China(No.2016YFB0900600)。
文摘Voltage source converter based high-voltage direct current(VSC-HVDC)transmission technology has been extensively employed in power systems with a high penetration of renewable energy resources.However,connecting a voltage source converter(VSC)to an AC weak grid may cause the converter system to become unstable.In this paper,a phase-shift phaselocked loop(PS-PLL)is proposed wherein a back electromotive force(BEMF)observer is added to the conventional phaselocked loop(PLL).The BEMF observer is used to observe the voltage of the infinite grid in the stationaryαβframe,which avoids the problem of inaccurate observations of the grid voltage in the dq frame that are caused by the output phase angle errors of the PLL.The VSC using the PS-PLL can operate as if it is facing a strong grid,thus enhancing the stability of the VSC-HVDC system.The proposed PS-PLL only needs to be properly modified on the basis of a traditional PLL,which makes it easy to implement.In addition,because it is difficult to obtain the exact impedance of the grid,the influence of shortcircuit ratio(SCR)estimation errors on the performance of the PS-PLL is also studied.The effectiveness of the proposed PSPLL is verified by the small-signal stability analysis and timedomain simulation.
基金supported by the National Natural Science Foundation of China under Grant 62004028,62090041the Science Foundation of Sichuan under Grant 2022NSFSC0927.
文摘This article overviews the design considerations and state-of-the-art of the ring voltage-controlled oscillator(VCO)-based phase-locked loops(PLLs)for clock generation in different applications.Partic-ularly,the objective of the current work is to evaluate the required PLL performance among the fundamental metrics of power,jitter and area.An in-depth treatment of the mainstream PLL architectures and the associated design techniques enables them to be compared analyt-ically and benchmarked with respect to their figure-of-merit(FoM).The paper also summarizes the key concerns on the selection of dif-ferent circuit techniques to optimize the clock performance under dif-ferent scenarios.
文摘In order to solve problems in high dynamic environment, a frequency-locked loop (FLL) assisted phase-locked loop (PLL) is put forward for carrier tracking. On the basis of the analysis of discriminators, the total phase error of the tracking loop is analyzed and a general error expression is derived. By using linearization and Jaffe-Rechtin coefficients, the performance of a special first order FLL-assisted second order PLL is analyzed to get a closed expression. Analysis results and simula- tions show that there exist an optimal FLL loop bandwidth and a optimal PLL loop bandwidth which can make the phase jitter much less than that when the PLL is used alone.
基金Supported by the Fund of National Defense Industry Innova-tive Team(231)
文摘An S-band frequency synthesizer for a stepped-frequency radar is presented. This frequen- cy synthesizer is based on a direct digital synthesizer ( DDS ) -driven wideband phase-locked loop (PLL) architecture which can achieve low spurious noise and rapid frequency hopping simultaneous- ly. The mechanism of introducing high level spurs by the images of DDS digital to analog convertor (DAC) output is analyzed. A novel DDS frequency planning method is proposed to ensure low col- ored noise within the entire bandwidth. The designed output frequency range is 3. 765 -4. 085 GHz, and the step size is 5 MHz with frequency agility of less than 1 μs. Measured results demonstrate that the average spurious free dynamic range (SFDR) is about 64 dBc in a 320 MHz bandwidth.
文摘This paper proposes a novel Gm-C loop filter instead of a conventional passive loop filter used in a phase-locked loop. The innovative advantage of the proposed architecture is tunable loop filter bandwidth and hence the process variations of passive elements of resistance R and capacitance C can be overcome and the chip area is greatly reduced. Furthermore, the MASH 1-1-1 sigma-delta (ZA) modulator is adopted for performing the fractional division number and hence improves the phase noise as well. Measured results show that the locked phase noise is -114.1 dBc/Hz with lower Gm-C bandwidth and -111.7 dBm/C with higher Gm-C bandwidth at 1 MHz offset from carrier of 5.68 GHz. Including pads and built-in Gm-C filter, the chip area of the proposed frequency synthesizer is 1.06 mm2. The output power is -8.69 dBm at 5.68 CHz and consumes 56 mW with an off-chip buffer from 1.8-V supply voltage.
基金This work is supported in part by the National Natural Science Foundation of China(No.51807089,51877104)in part by the Natural Science Foundation of Jiangsu Province(No.BK20180432).
文摘In renewable power generation systems,ensuring the synchronization of the inverter and the power grid is crucial for the stable operation of grid-connected inverters.Nowadays,the phase-locked loop(PLL)technology has become a widely used grid synchronization method because of its simple implementation and robustness under various grid conditions.Even though a lot of PLLs have been proposed,an overview and comparative analysis of multiple PLLs can be helpful for practical applications.In addition,the weak grid condition is a great challenge for the system.Therefore,this study first presents an overview of the existing PLLs together with their general structures and basic working principles.Depending on the implementation of the phase detector,the PLL can be divided into three categories:power-based PLL(pPLL),orthogonal-signalgenerator-based PLL(OSG-PLL)and adaptive-filter-based PLL(AF-PLL).Then,from the above classification,seven typical single-phase PLLs are selected for further study.Finally,some test results are given,and a comprehensive evaluation of the selected PLLs under different grid conditions is conducted.
文摘A high-speed dual-modulus divide-by-32/33 prescaler has been developed using 0.25 μm CMOS technology. The source-coupled logic (SCL) structure is used to reduce the switching noise and to ameliorate the power-speed tradeoff. The proposed prescaler can operate at high frequency with a low-power consumption. Based on the 2.5 V, 0.25 μm CMOS model, simulation results indicate that the maximum input frequency of the prescaler is up to 3.2 GHz. Running at 2.5 V, the circuit consumes only 4.6 mA at an input frequency 2.5 GHz.
文摘As the proportion of converter-interfaced renewable energy resources in the power system is increasing,the strength of the power grid at the connection point of wind turbine generators(WTGs)is gradually weakening.Existing research has shown that when connected with the weak grid,the stability of the traditional grid-following controlled converters will deteriorate,and they are prone to unstable phenomena such as oscillation.Due to the limitations of linear analysis that cannot sufficiently capture the stability phenomena,transient stability must be investigated.So far,standalone time-domain simulations or analytical Lyapunov stability criteria have been used to investigate transient stability.However,the time-domain simulations have proven to be computationally too heavy,while analytical methods are difficult to formulate for larger systems,require many modelling assumptions,and are often conservative in estimating the stability boundary.This paper proposes and demonstrates an innovative approach to estimating the transient stability boundary via combining the linear Lyapunov function and the reverse-time trajectory technique.The proposed methodology eliminates the need of time-consuming simulations and the conservative nature of Lyapunov functions.This study brings out the clear distinction between the stability boundaries with different post-fault active current ramp rate controls.At the same time,it provides a new perspective on critical clearing time for wind turbine systems.The stability boundary is verified using time-domain simulation studies.
基金supported by Academy of Finland,Russian Ministryof Education and Science(Federal Target Program)Russian Foundation for Basic Research and Saint-Petersburg State University
文摘The analysis of stability and numerical simulation of Costas loop circuits for the high-frequency signals is a challenging task. The problem lies in the fact that it is necessary to observe very fast time scale of input signals and slow time scale of signal s phases simultaneously. To overcome this difficulty, it is possible to follow the classical ideas of Gardner and Viterbi to construct a mathematical model of Costas loop, in which only slow time change of signal s phases and frequencies is considered. Such an construction, in turn,requires the computation of phase detector characteristic, depending on the waveforms of the considered signals. In this paper, the problems of nonlinear analysis of Costas loops and the approaches to the simulation of the classical Costas loop, the quadrature phase shift keying(QPSK) Costas loop, and the two-phase Costas loop are discussed. The analytical method for the computation of phase detector characteristics of Costas loops is described.
基金the National Natural Science Foundation of China(No. 50677014)the Specialized Research Fund for the Doctoral Program of Higher Education(No. 20060532002)
文摘A novel method based on the analysis of instantaneous phase is proposed to extract the jitter on phase-locked loops output clock. The method utilizes the Hilbert transform to extend the real signal of PLLs output into an analytic signal, and the implementation of Hilbert transform is based on the Fourier transform windowed with Hamming window. Then, the jitter of clock is extracted from the instantaneous phase of analytic signal. The experimental results of simulations validate that the proposed method can effectively extract the jitter on PLL clock, and it has better performance by comparing the sinusoidal jitter extraction results with the other methods.
文摘Phase-locked loops (PLLs) are essential wherever a local event is synchronized with a periodic external event. They are utilized as on-chip clock frequency generators to synthesize a low skew and higher internal frequency clock from an external lower frequency signal and its characterization and measurement have recently been calling for more and more attention. In this paper, a built-in on-chip circuit for measuring jitter of PLL based on a duty cycle modulation vernier delay line is proposed and demonstrated. The circuit employs two delay lines to measure the timing difference and transform the difference signal into digital words. The vernier lines are composed of delay cells whose duty cycle can be adjusted by a feedback voltage. It enables the circuit to have a self calibration capability which eliminates the mismatch problem caused by the process variation.