Abstract: Phase-locked loops (PLLs) are provided. A PLL includes a voltage-controlled oscillator (VCO), a frequency divider and a track-and-hold charge pump. The VCO is configured to provide an output clock corresponding to a pumping current. The frequency divider is configured to provide a feedback signal according to the output clock. The track-and-hold charge pump is configured to provide the pumping current according to a reference clock and the feedback signal. The track-and-hold charge pump includes a track-and-hold circuit, a pumping switch and a pulse width modulator (PWM). The track-and-hold circuit is coupled to the frequency divider and configured to sample the feedback signal according to the reference clock. The PWM is configured to provide a PWM signal to control the pumping switch according to the reference clock, so as to provide the pumping current corresponding to the sampled feedback signal.

Abstract: Phase-locked loops (PLLs) are provided. A PLL includes a voltage-controlled oscillator (VCO), a frequency divider and a track-and-hold charge pump. The VCO is configured to provide an output clock corresponding to a pumping current. The frequency divider is configured to provide a feedback signal according to the output clock. The track-and-hold charge pump is configured to provide the pumping current according to a reference clock and the feedback signal. The track-and-hold charge pump includes a track-and-hold circuit, a pumping switch and a pulse width modulator (PWM). The track-and-hold circuit is coupled to the frequency divider and configured to sample the feedback signal according to the reference clock. The PWM is configured to provide a PWM signal to control the pumping switch according to the reference clock, so as to provide the pumping current corresponding to the sampled feedback signal.

Abstract: Phase-locked loops (PLLs) are provided. A PLL includes a voltage-controlled oscillator (VCO), a frequency divider, a track-and-hold charge pump, and a frequency tracking circuit. The VCO is configured to provide an output clock corresponding to a pumping current. The frequency divider is configured to divide the output clock to provide a feedback signal. The track-and-hold charge pump is configured to provide the pumping current according to a reference clock and the feedback signal. The frequency tracking circuit is configured to decrease frequency error between the feedback signal and the reference clock. The track-and-hold charge pump includes a pumping switch and a pulse width modulator (PWM). The PWM is configured to provide a PWM signal to control the pumping switch according to the reference clock, so as to provide the pumping current corresponding to the feedback signal.

Abstract: Phase-locked loops (PLLs) are provided. A PLL includes a voltage-controlled oscillator (VCO), a frequency divider, a track-and-hold charge pump, and a frequency tracking circuit. The VCO is configured to provide an output clock corresponding to a pumping current. The frequency divider is configured to divide the output clock to provide a feedback signal. The track-and-hold charge pump is configured to provide the pumping current according to a reference clock and the feedback signal. The frequency tracking circuit is configured to decrease frequency error between the feedback signal and the reference clock. The track-and-hold charge pump includes a pumping switch and a pulse width modulator (PWM). The PWM is configured to provide a PWM signal to control the pumping switch according to the reference clock, so as to provide the pumping current corresponding to the feedback signal.

Abstract: Track-and-hold charge pumps and PLL are provided. A track-and-hold charge pump includes a track-and-hold circuit, a transconductance amplifier, a pulse width modulator (PWM), and a pumping switch coupled to the transconductance amplifier. The track-and-hold circuit samples an input signal according to a reference clock. The transconductance amplifier converts the sampled input signal into a current. The PWM provides a PWM signal according to the reference clock. The pumping switch is controlled by the PWM signal, to provide an output current according to the current.

Abstract: A phase-locked loop circuit is disclosed. The circuit includes a digital bang-bang phase-locked loop (PLL) electrically connected to an input clock signal connection and an output clock signal connection, and a down-sampling circuit connected to the input clock signal connection. The circuit also includes a digitally-controlled delay line receiving an output of the down-sampling circuit, and an injection pulser receiving an output of the digitally-controlled delay line and connected to provide an injection pulse to a portion of the digital bang-bang phase-locked loop (PLL). The circuit further includes an injection timing calibration circuit connected to a control input of the digitally-controlled delay line. The circuit provides calibration of injection timing and bandwidth optimization, thereby reducing jitter in an output signal from the PLL.

Abstract: A phase-locked loop circuit is disclosed. The circuit includes a digital bang-bang phase-locked loop (PLL) electrically connected to an input clock signal connection and an output clock signal connection, and a down-sampling circuit connected to the input clock signal connection. The circuit also includes a digitally-controlled delay line receiving an output of the down-sampling circuit, and an injection pulser receiving an output of the digitally-controlled delay line and connected to provide an injection pulse to a portion of the digital bang-bang phase-locked loop (PLL). The circuit further includes an injection timing calibration circuit connected to a control input of the digitally-controlled delay line. The circuit provides calibration of injection timing and bandwidth optimization, thereby reducing jitter in an output signal from the PLL.

Abstract: Track-and-hold charge pumps and PLL are provided. A track-and-hold charge pump includes a track-and-hold circuit, a transconductance amplifier, a pulse width modulator (PWM), and a pumping switch coupled to the transconductance amplifier. The track-and-hold circuit samples an input signal according to a reference clock. The transconductance amplifier converts the sampled input signal into a current. The PWM provides a PWM signal according to the reference clock. The pumping switch is controlled by the PWM signal, to provide an output current according to the current.

Abstract: Systems and methods for automatically controlling one or more parameters of a digital phase-locked loop (DPLL) circuit are provided. A phase error signal generated by a phase detector of the DPLL circuit is received. A delayed version of the phase error signal is generated. A product of the phase error signal and the delayed version of the phase error signal is generated. The product is integrated, and a first output for controlling a gain of a proportional path of the DPLL circuit is generated based on the integrated product. The first output is down-sampled. A least-mean-square (LMS) filter is used to generate a second output that minimizes a value of the down-sampled output. A gain of an integral path of the DPLL is controlled based on the second output.