A display device including: a timing controller outputting a reference dock signal and a data packet, wherein the data packet includes a dock signal embedded in a data signal; a dock and data recovery (CDR) circuit receiving the reference clock signal and the data packet; and a display panel displaying an image based on the data packet, wherein, when the CDR circuit receives the reference clock signal, a frequency band of the reference clock signal is detected using a first internal clock signal, a parameter associated with jitter characteristics of the clock and data recovery circuit is adjusted according to the detected frequency band, and a second internal clock signal is output by adjusting a frequency of the first internal clock signal, and when the CDR circuit receives the data packet, the data signal and a clock signal synchronized with the data signal are recovered from the data packet.

A display device including: a timing controller outputting a reference clock signal and a data packet, wherein the data packet includes a clock signal embedded in a data signal; a clock and data recovery (CDR) circuit receiving the reference clock signal and the data packet; and a display panel displaying an image based on the data packet, wherein, when the CDR circuit receives the reference clock signal, a frequency band of the reference clock signal is detected using a first internal clock signal, a parameter associated with jitter characteristics of the clock and data recovery circuit is adjusted according to the detected frequency band, and a second internal clock signal is output by adjusting a frequency of the first internal clock signal, and when the CDR circuit receives the data packet, the data signal and a clock signal synchronized with the data signal are recovered from the data packet.

A phase locked loop circuit includes a phase comparator that compares phases of a reference signal through a first frequency divider and a local signal through a second frequency divider to output a phase comparison signal; a loop filter that smooths the phase comparison signal to output the control voltage signal; a controller that sets frequency division ratios of the first and the second frequency dividers; a free-running voltage generator that generates a free-running voltage signal of the voltage control oscillator; a measurement circuit that measures a voltage of the control voltage signal; a storage circuit that stores therein the voltage of the control voltage signal; and a low-pass filter that transmits, to the voltage control oscillator, a corrected free-running voltage signal based on a free-running voltage correction value calculated by the free-running voltage generator based on the control voltage signal before the frequency division ratios are changed.

A reference-less clock and data recovery device includes a CDR circuit, an oscillator circuit, and a processor. The CDR circuit is configured to generate a first clock signal through synchronization according to a data signal having a first frequency in a first time period. The oscillator circuit is configured to output an oscillating clock signal according to the first clock signal. A frequency of the oscillating clock signal is substantially identical to that of the first clock signal. The processor oversamples the data signal having a second frequency in a second time period to generate a simulated preparation signal conforming to the second frequency. The CDR circuit is configured to generate a second clock signal through synchronization according to the simulated preparation signal. Before generating the second clock signal, the CDR circuit is synchronized to the oscillating clock signal to maintain outputting of the first clock signal.

An apparatus includes a phase-locked loop and a jitter detection circuit. A method of detecting a jitter in the apparatus includes the phase-locked loop generating a lead control signal and a lag control signal according to a reference clock and a feedback clock, the jitter detection circuit generating a jitter signal according to the lead control signal and the lag control signal, the jitter detection circuit generating a jitter window signal according to the jitter signal, the jitter detection circuit identifying jitters in the clock signal according to the jitter signal and the jitter window signal, and the jitter detection circuit outputting a jitter indication signal according to the number of jitters identified.

A reference-less dock and data recovery device includes a CDR circuit, an oscillator circuit, and a processor. The CDR circuit is configured to generate a first clock signal through synchronization according to a data signal having a first frequency in a first time period. The oscillator circuit is configured to output an oscillating clock signal according to the first clock signal, A frequency of the oscillating clock signal is substantially identical to that of the first clock signal. The processor oversamples the data signal having a second frequency in a second time period to generate a simulated preparation signal conforming to the second frequency. The CDR circuit is configured to generate a second clock signal through synchronization according to the simulated preparation signal. Before generating the second clock signal, the CDR circuit is synchronized to the oscillating clock signal to maintain outputting of the first clock signal.

An analog PLL comprising: a VCO configured to provide a PLL output signal; a phase detector (PD) configured to receive a feedback signal from the VCO and a reference signal and wherein the PD provides a PD signal to a low pass filter (LPF), the LPF configured to filter of the PD signal and provide the filtered signal as a tuning voltage for the VCO; and a tracking loop configured to receive the tuning voltage and comprising at least a tracking loop comparator configured to provide a comparator output voltage based on a difference between the tuning voltage and a target voltage, wherein an output of the tracking loop provides a tracking voltage based on the comparator output voltage and wherein the frequency of the PLL output voltage is based on the tuning voltage and the tracking voltage.

A PLL has a tunable resonator including an inductance and variable capacitance coupled between first and second nodes, and capacitances coupleable between the nodes. A control node is coupled to the variable capacitance and receives a control signal for tuning the resonator. A biasing circuit biases the resonator to generate an output. A PFD circuit senses timing offset of the output with respect to a reference and asserts first or second digital signals dependent on the sign of the timing offset. A charge pump generates the control signal based on the first and second digital signals. A timer asserts a timing signal in response to a pulse sensed in a reset signal and de-asserts the timing signal after a time interval. A calibrator couples selected capacitances between the first and second nodes as a function of the second digital signal, in response to assertion of the timing signal.

A display device including: a timing controller outputting a reference clock signal and a data packet, wherein the data, packet includes a clock signal embedded in a data signal; a clock and data recovery (CDR) circuit receiving the reference clock signal and the data packet; and a display panel displaying an image based on the data packet, wherein, when the CDR circuit receives the reference clock signal, a frequency band of the reference clock signal is detected using a first internal clock signal, a parameter associated with jitter characteristics of the clock and data recovery circuit is adjusted according to the detected frequency band, and a second internal clock signal is output by adjusting a frequency of the first internal clock signal and when the CDR circuit receives the data packet, the data signal and a clock signal synchronized with the data signal are recovered from the data packet.

A phase-locked loop circuit comprises an oscillator having a plurality of operating curves and being suitable for generating an output signal. In a calibration state the oscillator is trimmed to an operating curve for use in a normal operation state. The phase-locked loop circuit further comprises a phase/frequency detector being suitable for generating at least one error signal based on an input signal and a feedback signal generated on the basis of the output signal. The phase-locked loop circuit further comprises a loop filter being suitable for generating a loop-filter signal based on the at least one error signal, the loop-filter signal being applied to the oscillator in the normal operation state. The phase-locked loop circuit further comprises a calibration circuit being suitable for trimming the oscillator to the operating curve for use in the normal operation state on the basis of the at least one error signal.