A sub-sampling phase-locked loop includes a first phase output unit sub-sampling an output clock of a digitally-controlled oscillator and outputting a sign bit corresponding to a voltage-domain phase and a second phase output unit outputting a gain bit corresponding to a time-domain phase based on a pulse width set according to the output clock and a threshold time set according to the reference clock.

Methods and apparatus for performing a high speed phase demodulation scheme using a low bandwidth phase-lock loop are disclosed. An example apparatus includes a low bandwidth phase lock loop to lock to a data signal at a first phase, the data signal capable of oscillating at the first phase or a second phase; and output a first output signal at the first phase and a second output signal at the second phase, the first output signal or the second output signal being utilized in a feedback loop of the low bandwidth phase lock loop. The example apparatus further includes a fast phase change detection circuit coupled to the low bandwidth phase lock loop to determine whether the data signal is oscillating at the first phase or the second phase.

Methods and apparatus for performing a high speed phase demodulation scheme using a low bandwidth phase-lock loop are disclosed. An example apparatus includes a low bandwidth phase lock loop to lock to a data signal at a first phase, the data signal capable of oscillating at the first phase or a second phase; and output a first output signal at the first phase and a second output signal at the second phase, the first output signal or the second output signal being utilized in a feedback loop of the low bandwidth phase lock loop. The example apparatus further includes a fast phase change detection circuit coupled to the low bandwidth phase lock loop to determine whether the data signal is oscillating at the first phase or the second phase.

One example includes a phase-locked loop (PLL) circuit. The circuit includes a frequency divider and phase detector configured to generate a plurality of non-overlapping switching signals based on an input signal and a PLL output signal. The circuit also includes a linear frequency-to-current (F2I) converter configured to generate a control current having an amplitude that is based on the plurality of non-overlapping switching signals. The circuit further includes a linear current-controlled oscillator configured to generate the PLL output signal to have a frequency and phase to be approximately equal to the input signal based on the amplitude of the control current.

One example includes a phase-locked loop (PLL) circuit. The circuit includes a frequency divider and phase detector configured to generate a plurality of non-overlapping switching signals based on an input signal and a PLL output signal. The circuit also includes a linear frequency-to-current (F2I) converter configured to generate a control current having an amplitude that is based on the plurality of non-overlapping switching signals. The circuit further includes a linear current-controlled oscillator configured to generate the PLL output signal to have a frequency and phase to be approximately equal to the input signal based on the amplitude of the control current.

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.

Phase-locked loop circuitry to generate an output signal, the phase-locked loop circuitry comprising oscillator circuitry, switched resistor loop filter, coupled to the input of the oscillator circuitry (which, in one embodiment, includes a voltage-controlled oscillator), including a switched resistor network including at least one resistor and at least one capacitor, wherein an effective resistance of the switched resistor network is responsive to and increases as a function of one or more pulsing properties of a control signal (wherein pulse width and frequency (or period) are pulsing properties of the control signal), phase detector circuitry, having an output which is coupled to the switched resistor loop filter, to generate the control signal (which may be periodic or non-periodic). The phase-locked loop circuitry may also include frequency detection circuitry to provide a lock condition of the phase-locked loop circuitry.

Phase-locked loop circuitry to generate an output signal, the phase-locked loop circuitry comprising oscillator circuitry, switched resistor loop filter, coupled to the input of the oscillator circuitry (which, in one embodiment, includes a voltage-controlled oscillator), including a switched resistor network including at least one resistor and at least one capacitor, wherein an effective resistance of the switched resistor network is responsive to and increases as a function of one or more pulsing properties of a control signal (wherein pulse width and frequency (or period) are pulsing properties of the control signal), phase detector circuitry, having an output which is coupled to the switched resistor loop filter, to generate the control signal (which may be periodic or non-periodic). The phase-locked loop circuitry may also include frequency detection circuitry to provide a lock condition of the phase-locked loop circuitry.

An apparatus is provided to improve lock time of a phase locked loop, wherein the apparatus comprises: a ring oscillator including at least two delay stages, wherein each delay stage has a controllable delay; and a multiphase frequency monitor coupled to the ring oscillator to monitor frequency at an output of at least two delay stages of the ring oscillator.

A sub-sampler phase locked loop (SSPLL) system having a frequency locking loop (FLL) and a phase locked loop (PLL) is disclosed. The FLL is configured to detect frequency variations between a phase locked loop (PLL) output signal and a reference frequency and automatically generate a pulsed correction signal upon the detected frequency variations and apply the pulsed correction signal to a voltage controlled oscillator (VCO) control voltage. The PLL is configured to generate the PLL output signal based on the VCO control voltage.