Methods and systems are described for receiving N phases of a local clock signal and M phases of a reference signal, wherein M is an integer greater than or equal to 1 and N is an integer greater than or equal to 2, generating a plurality of partial phase error signals, each partial phase error signal formed at least in part by comparing (i) a respective phase of the M phases of the reference signal to (ii) a respective phase of the N phases of the local clock signal, and generating a composite phase error signal by summing the plurality of partial phase error signals, and responsively adjusting a fixed phase of a local oscillator using the composite phase error signal.

Generating, at a plurality of delay stages of a local oscillator, a plurality of phases of a local oscillator signal, generating a loop error signal based on a comparison of one or more phases of the local oscillator signal to one or more phases of a received reference clock, generating a plurality of phase-specific quadrature error signals, each phase-specific quadrature error signal associated with a respective phase of the plurality of phases of the local oscillator signal, each phase-specific quadrature error signal based on a comparison of the respective phase to two or more other phases of the local oscillator signal, and adjusting each delay stage according to a corresponding phase-specific quadrature error signal of the plurality of phase-specific quadrature error signals and the loop error signal.

A TAF-DPS based circuits and methods to improve electronic system's frequency accuracy and enhance its frequency stability is disclosed in this application. Present invention creates a circuit architecture and a calculation scheme for compensating frequency source's frequency error. Present invention further discloses a method of incorporating said scheme into functional chip built in either ASIC or FPGA fashion. Present invention further presents a method of using TAF-DPS-frequency-compensation-scheme-equipped-chips as nodes in electronic network. As a result, the circuit and apparatus disclosed in present invention can improve electronic system's performance from the time synchronization perspective.

A time-to-digital converter includes a first oscillation circuit that starts oscillating at the transition timing of a first signal and generates a first clock signal having a first clock frequency, a second oscillation circuit that starts oscillating at the transition timing of a second signal and generates a second clock signal having a second clock frequency, a first adjustment circuit that adjusts the oscillation frequency of the first oscillation circuit based on a reference clock signal, a second adjustment circuit that adjusts the oscillation frequency of the second oscillation circuit based on the reference clock signal, and a processing circuit that converts the time difference between the transition timing of the first signal and the transition timing of the second signal into a digital value based on the first and second clock signals.

Two rings of a voltage controlled oscillator (VCO) configured to generate a plurality of phases of an oscillator signal, each ring of the two rings comprising three stages of inverters configured to generate a subset of phases of the plurality of phases of the oscillator signal, cross coupled via each stage to a corresponding stage in an other ring of the two rings using inverters to inverse-phase lock the subsets of phases of the plurality of phases of the oscillator signal of the two rings, and configured to receive inputs at each stage from a previous stage in the ring and a feed-forward signal from a successive stage in the other ring of the two rings, and a tail current supply configured to supply the two rings of the VCO with a tail current, the tail current comprising a low-magnitude proportional component and a high-magnitude integral component.

A circuit includes a first ring oscillator with a plurality of stages, each coupled via a voltage follower cross-coupling to a plurality of stages of a second ring oscillator. Further ring oscillators may be coupled to the first ring oscillator and the second ring oscillator. Additionally, the voltage follower cross-coupling for each of the stages may include one or more first voltage follower having a first strength, and one or more second voltage follower having a second strength different than the first strength.

A multi-phase clock circuit includes a first delay circuit, a second delay circuit, a third delay circuit, a first clock mixer circuit, and a second clock mixer circuit. The first, second, and third delay circuits are coupled in series. The first clock mixer circuit includes a first input and a second input. The first input is coupled to an output of the first delay circuit. The second input is coupled to an output of the second delay circuit. The second clock mixer circuit also includes a first input and a second input. The first input of the second clock mixer circuit is coupled to an output of the second delay circuit. The second input of the second clock mixer circuit is coupled to an output of the third delay circuit.

In generating a mask signal used to recover a clock signal embedded in an interface signal, the mask signal may be generated by comparing a plurality of comparison signals, generated by delaying a plurality of mask rising signals by a predetermined time, with the clock signal and selecting one mask rising signal used to generate a comparison signal close to one portion of the clock signal from among the plurality of mask rising signals.

An apparatus and a method are provided. The apparatus includes an analog-to-digital converter (ADC) driver; and an ADC that is electrically coupled to the ADC driver. The method includes setting, by an analog-to-digital converter (ADC) driver, a desired common-mode control value based on the held voltage; and setting, by the ADC driver, a desired gain control value based on the held voltage.

Disclosed is a receiver circuit comprising an analog-to-digital converter (ADC) circuit having an analog input, a clock input, and a digital output, and a clock divider circuit having a reference clock input and a phase selector input, and having a clock output coupled to the clock input of the ADC circuit. The clock divider circuit is configured to divide a reference clock signal coupled to the reference clock input at a reference clock frequency, to produce a clock output signal at an ADC clock frequency, at the clock output, such that the reference clock frequency is an integer multiple N of the ADC clock frequency. The clock divider circuit is further configured to select from among a plurality of selectable phases of the clock output signal, responsive to a phase selector signal applied to the phase selector input.