An apparatus includes an oscillator, a frequency divider, a phase circuit, a charge pump, and a filter. The frequency divider may generate an early feedback signal using a clock signal, and may assert a feedback signal a number of periods of the clock signal after asserting the early feedback signal. The phase circuit may generate a charge control signal using a reference clock signal and the feedback signal, and may generate a discharge control signal using the early feedback signal, the reference clock signal, and the feedback signal. The charge pump may charge or discharge a circuit node using the charge control signal and the discharge control signal to generate a frequency control signal. The filter circuit may attenuate at least one frequency component of the frequency control signal. The oscillator circuit may modify a frequency of the clock signal using the frequency control signal.

An apparatus includes an oscillator, a frequency divider, a phase circuit, a charge pump, and a filter. The frequency divider may generate an early feedback signal using a clock signal, and may assert a feedback signal a number of periods of the clock signal after asserting the early feedback signal. The phase circuit may generate a charge control signal using a reference clock signal and the feedback signal, and may generate a discharge control signal using the early feedback signal, the reference clock signal, and the feedback signal. The charge pump may charge or discharge a circuit node using the charge control signal and the discharge control signal to generate a frequency control signal. The filter circuit may attenuate at least one frequency component of the frequency control signal. The oscillator circuit may modify a frequency of the clock signal using the frequency control signal.

There is disclosed an apparatus comprising a first phase-locked loop comprising: a phase detector (302, 304), arranged to receive a reference clock signal (306) and a feedback clock signal (308) and to output a frequency control signal based on a phase difference between the reference clock signal (306) and the feedback clock signal (308); a variable-frequency oscillator (312, 314) arranged to output an oscillator signal having a frequency dependent on said frequency control signal; first divider circuitry (316) for generating said feedback clock signal (308) by frequency-dividing said oscillator signal; and second divider circuitry (320) for generating an output clock signal (3220 by frequency-dividing said oscillator signal; wherein a phase relation between said first divider circuitry (316) and said second divider circuitry (320) is adjustable to delay or advance said output clock signal (322) relative to said feedback clock signal (308). The apparatus may be a radar receiver or transceiver.

There is disclosed an apparatus comprising a first phase-locked loop comprising: a phase detector (302, 304), arranged to receive a reference clock signal (306) and a feedback clock signal (308) and to output a frequency control signal based on a phase difference between the reference clock signal (306) and the feedback clock signal (308); a variable-frequency oscillator (312, 314) arranged to output an oscillator signal having a frequency dependent on said frequency control signal; first divider circuitry (316) for generating said feedback clock signal (308) by frequency-dividing said oscillator signal; and second divider circuitry (320) for generating an output clock signal (3220 by frequency-dividing said oscillator signal; wherein a phase relation between said first divider circuitry (316) and said second divider circuitry (320) is adjustable to delay or advance said output clock signal (322) relative to said feedback clock signal (308). The apparatus may be a radar receiver or transceiver.

A first 1:N frequency divider has an input configured to be coupled to one of two signals and a second 1:N frequency divider has an input configured to be coupled to another of the two signals. A mixer includes two inputs, where each input is coupled to an output of one of the first and second 1:N frequency dividers. A low-pass filter has an input coupled to an output of the mixer and an analog-to-digital converter (ADC) has an input coupled to an output of the low-pass filter. A data collection and analysis block repeatedly changes a phase of an output of the first 1:N divider, collects a set of digitized data generated by the ADC, and estimates the phase difference between the two signals based on the set of digitized data.

A first 1:N frequency divider has an input configured to be coupled to one of two signals and a second 1:N frequency divider has an input configured to be coupled to another of the two signals. A mixer includes two inputs, where each input is coupled to an output of one of the first and second 1:N frequency dividers. A low-pass filter has an input coupled to an output of the mixer and an analog-to-digital converter (ADC) has an input coupled to an output of the low-pass filter. A data collection and analysis block repeatedly changes a phase of an output of the first 1:N divider, collects a set of digitized data generated by the ADC, and estimates the phase difference between the two signals based on the set of digitized data.

A system may include a clock and data recovery circuit that includes one or more analog components. The system may also include a digital control circuit configured to control the clock and data recovery circuit. The digital control circuit and the clock and data recovery circuit may be formed on a single substrate.

This application relates to a device and a method for eliminating electromagnetic interference (EMI). The device for eliminating EMI includes: a timing control chip; and a phase-locked loop module, electrically connected to the timing control chip and including: a phase detection unit, configured to detect a frequency generated by a clock cycle to generate a frequency difference; a charge pump unit, configured to generate a regulation voltage; a voltage-controlled oscillator unit, configured to control an oscillation frequency when the regulation voltage is input; a plurality of frequency divider units, configured to generate a new output clock frequency by using an input clock frequency; and a selector unit, configured to select the appropriate frequency divider units, where the selector unit has another end electrically connected to needed power circuits.

A phase locked loop has a frequency divider included in a feedback path. The frequency divider generates a first output and a delayed output. The phase locked loop also includes a charge pump to generate an output current based on the first output and the delayed output of the frequency divider.

A phase locked loop has a frequency divider included in a feedback path. The frequency divider generates a first output and a delayed output. The phase locked loop also includes a charge pump to generate an output current based on the first output and the delayed output of the frequency divider.