The technology of this application relates to a phase-locked loop circuit that includes a phase frequency detector, a first voltage control module, a second voltage control module, a third voltage control module, a voltage-controlled oscillator, and a frequency divider. A first output end of the phase frequency detector is connected to a first input end of the first voltage control module and a first input end of the second voltage control module, a second output end of the phase frequency detector is connected to a second input end of the first voltage control module and a second input end of the second voltage control module, an output end of the first voltage control module.

A clock data recovery circuit includes the following elements: a phase detector for outputting a phase adjustment signal by comparing a clock signal of a first node and an input signal; a charge pump for adjusting a charge amount of a second node according to the phase adjustment signal; a first switch including one end coupled to the second node and including another end coupled to a third node; a second switch including one end which receives a bias voltage and including another end coupled to the third node; a capacitor including a first electrode coupled to the third node; third switches; and voltage control oscillators including control terminals coupled to the third node and including output terminals coupled to the first node through the third switches.

Phase Locked Loop, PLL, circuitry comprising a phase detector configured to generate a first pulse signal comprising at least one first pulse, a property of each first pulse being indicative of a phase difference between a reference signal and a feedback signal; a pulse repeater circuit configured, based on the first pulse signal, to generate a second pulse signal comprising, for each first pulse, a second pulse generated by repeating the corresponding first pulse; and an oscillator configured to generate the feedback signal and control a frequency of the feedback signal based on the second pulse signal.

Phase Locked Loop, PLL, circuitry comprising a phase detector configured to generate a first pulse signal comprising at least one first pulse, a property of each first pulse being indicative of a phase difference between a reference signal and a feedback signal; a pulse repeater circuit configured, based on the first pulse signal, to generate a second pulse signal comprising, for each first pulse, a second pulse generated by repeating the corresponding first pulse; and an oscillator configured to generate the feedback signal and control a frequency of the feedback signal based on the second pulse signal.

A PAM-4 receiver with jitter compensation clock and data recovery is provided. The receiver includes a first-order delay-locked loop (DLL) which employs a bang-bang phase detector (BBPD) and a voltage-controlled delay line (VCDL) circuit supporting 40 MHz jitter tracking bandwidth and static phase skew elimination. A second-order wideband phase-locked loop (WBPLL) using the ¼-rate reference clock provides multi-phase clock generation with low input-to-output latency. To suppress the consequent jitter transfer, a jitter compensation circuit (JCC) acquires the jitter transfer amplitude and frequency information by detecting the DLL loop filter voltage (VLF(s)) signal, and generates an inverted loop filter voltage signal, denoted as VLF.sub.INV(s). The VLF.sub.INV(S) modulates a group of complementary VCDLs (C-VCDLs) to attenuate the jitter transfer on both recovered clock and data. With the provided receiver, a jitter compensation ratio up to 60% can be supported from DC to 4 MHz, with a −3-dB corner frequency of 40 MHz.

Disclosed is a frequency dividing circuit, a frequency dividing method and a phase locked loop. The frequency dividing circuit comprises: a clock selection unit outputting a first clock signal, select a second clock signal lagging behind the first clock signal by (½-1/M) of one phase; an integer frequency dividing unit performing frequency division on the first clock signal to provide a frequency-divided clock signal; a trigger unit triggering the frequency-divided clock signal according to the second clock signal to obtain a modulation clock signal; a switching signal unit providing a switching signal according to the modulation clock signal and a preset target output frequency. The clock selection unit selects and further outputs a third clock signal as the first clock signal according to the target phase selection information, to adjust the frequency of the frequency-divided clock signal, reduce noise and improve loop bandwidth of the phase locked loop.

A delay line includes first to n-th delay cells and a dummy delay cell, ‘n’ being an integer greater than or equal to 3. The first to n-th delay cells sequentially delay an input signal to respectively generate first to n-th output signals. The dummy delay cell delays the n-th output signal based on a delay control voltage to generate a dummy output signal. A delay amount of each of the first to (n−1)-th delay cells is adjusted on a basis of the delay control voltage and the output signal of the delay cell of a next stage of the corresponding delay cell, and a delay amount of the n-th delay cell is adjusted on a basis of the delay control voltage and the dummy output signal.

A delay line includes first to n-th delay cells and a dummy delay cell, ‘n’ being an integer greater than or equal to 3. The first to n-th delay cells sequentially delay an input signal to respectively generate first to n-th output signals. The dummy delay cell delays the n-th output signal based on a delay control voltage to generate a dummy output signal. A delay amount of each of the first to (n−1)-th delay cells is adjusted on a basis of the delay control voltage and the output signal of the delay cell of a next stage of the corresponding delay cell, and a delay amount of the n-th delay cell is adjusted on a basis of the delay control voltage and the dummy output signal.

The present invention relates to a field programmable gate array system that provides phase control with minimal latency.

A phase locked loop includes a phase detector outputting a first signal corresponding to a phase difference of a reference frequency signal and a division frequency signal, a charge pump amplifying a first signal to output a second signal, a loop filter filtering the second signal to output a third signal, a voltage-to-current converter receiving the third signal and outputting a fourth signal, a digital-to-analog converter outputting a fifth signal based on the fourth signal and a digital compensation signal, an oscillator outputting an output frequency signal having a frequency corresponding to the fifth signal, a divider dividing the frequency of the output frequency signal to output the division frequency signal and a compensation frequency signal, and an automatic frequency calibrator compensating for the voltage-to-current converter based on a difference between a frequency of the compensation frequency signal and a frequency of a reference frequency signal.