A delay time detection circuit includes below configurations. A clock generation unit generates a sub scale clock signal, based on a system clock signal. A count unit generates a count signal while sequentially and repeatedly incrementing a count number, based on the sub scale clock signal. A sub scale signal generation unit receives the count signal, and generates sub scale signals, equal in number to the count number, that each have, at a rate of once in the count number, a rectangular wave for a duration being associated with a second period and that are shifted in timing relative to one another according to the second period. A delay time calculation unit receives the input clock signal, and calculates a delay time within a range of the first period of the input clock signal with respect to the system clock signal, based on one of the sub scale signals.

An apparatus includes a phase frequency detector having a detector output and first and second inputs, the phase frequency detector configured to provide a phase difference signal at the detector output responsive to the first and second inputs. The apparatus also includes a gain controller having a controller input and a controller output, the controller input coupled to the detector output, and the gain controller configured to provide a digital value at the controller output responsive to the phase difference signal and a duty cycle. The apparatus also includes a pulse generator having a generator output and first and second generator inputs, the first generator input coupled to the controller output, the second generator input coupled to the second detector input, the pulse generator configured to provide a generator signal at the generator output responsive to the digital value and the second generator input.

A delay circuit with multiple dependencies on various environmental parameters is disclosed. The delay circuit is configured to receive an input signal. The delay circuit includes a first circuit configured to generate a first amount of delay, wherein the first amount of delay has a direct relationship to a first environmental parameter. The delay circuit also includes a second circuit configured to generate a second amount of delay such that the second amount of delay has an inverse relationship to a second environmental parameter. The delay circuit is configured to generate a delayed output signal based on the first and second amounts of delay generated by the first and second circuits.

A delay circuit with multiple dependencies on various environmental parameters is disclosed. The delay circuit is configured to receive an input signal. The delay circuit includes a first circuit configured to generate a first amount of delay, wherein the first amount of delay has a direct relationship to a first environmental parameter. The delay circuit also includes a second circuit configured to generate a second amount of delay such that the second amount of delay has an inverse relationship to a second environmental parameter. The delay circuit is configured to generate a delayed output signal based on the first and second amounts of delay generated by the first and second circuits.

A frequency estimator for estimating a frequency, including a counter configured to count an integer number of full clock cycles during a measurement time window; a Time-to-Digital Converter (TDC) configured to measure a fraction of a clock cycle during the measurement time window; and a processor configured to determine the estimated frequency based on the counted number of full clock cycles and the measured fraction of the clock cycle.

A frequency estimator for estimating a frequency, including a counter configured to count an integer number of full clock cycles during a measurement time window; a Time-to-Digital Converter (TDC) configured to measure a fraction of a clock cycle during the measurement time window; and a processor configured to determine the estimated frequency based on the counted number of full clock cycles and the measured fraction of the clock cycle.

Systems and methods are described for determining a phase measurement difference between a received modulated signal and a local clock signal. An adjusted local clock phase measurement may be determined by subtracting, from the phase measurement difference, a phase correction that is based on the frequency difference between the modulator signal's carrier frequency and the local clock's frequency. A phase modulation value may be generated by scaling the adjusted local clock phase measurement. The scaling may be based on a ratio of the modulated signal's carrier frequency and the local clock's frequency. The phase correction may be based on (i) a count of periods of the modulated signal occurring between each corrected phase measurement and (ii) a difference between the carrier frequency and the local clock frequency.

Systems and methods are described for determining a phase measurement difference between a received modulated signal and a local clock signal. An adjusted local clock phase measurement may be determined by subtracting, from the phase measurement difference, a phase correction that is based on the frequency difference between the modulator signal's carrier frequency and the local clock's frequency. A phase modulation value may be generated by scaling the adjusted local clock phase measurement. The scaling may be based on a ratio of the modulated signal's carrier frequency and the local clock's frequency. The phase correction may be based on (i) a count of periods of the modulated signal occurring between each corrected phase measurement and (ii) a difference between the carrier frequency and the local clock frequency.

A time measurement device for calculating a time from an input of a first trigger signal to an input of a second trigger signal as a measured time includes a start gate configured to generate a start signal, a stop gate configured to generate a stop signal, a TDC circuit configured to generate a digital code corresponding to the time from an input of a start signal to an input of a stop signal, a delay circuit configured to delay an input of at least one of the start signal and the stop signal to the TDC circuit by a predetermined delay time, and a control unit configured to calculate a measured time on the basis of a plurality of digital codes generated by the TDC circuit, wherein the time delay unit selects at least two delay times.

A time measurement device for calculating a time from an input of a first trigger signal to an input of a second trigger signal as a measured time includes a start gate configured to generate a start signal, a stop gate configured to generate a stop signal, a TDC circuit configured to generate a digital code corresponding to the time from an input of a start signal to an input of a stop signal, a delay circuit configured to delay an input of at least one of the start signal and the stop signal to the TDC circuit by a predetermined delay time, and a control unit configured to calculate a measured time on the basis of a plurality of digital codes generated by the TDC circuit, wherein the time delay unit selects at least two delay times.