An electronic device applies a frequency offset function to a first signal having a first frequency. The device includes a delay element configured to output a second signal corresponding to the first signal delayed by a duration equal to a first period of said signal divided by four. A circuit branch includes a first circuit configured to divide the frequency of the first signal by a given number coupled in series with a second circuit configured to implement an integration. The circuit branch outputs a third signal and a fourth signal. A single side band mixing circuit processes the first signal, second signal, third signal and fourth signal to generate an output signal.

An electronic device applies a frequency offset function to a first signal having a first frequency. The device includes a delay element configured to output a second signal corresponding to the first signal delayed by a duration equal to a first period of said signal divided by four. A circuit branch includes a first circuit configured to divide the frequency of the first signal by a given number coupled in series with a second circuit configured to implement an integration. The circuit branch outputs a third signal and a fourth signal. A single side band mixing circuit processes the first signal, second signal, third signal and fourth signal to generate an output signal.

A multi-loop clock signal generator includes a first phase-locked loop circuit configured to generate a control signal and a voltage-controlled oscillator configured to generate an output clock signal based on the control signal. The clock signal generator includes a second phase-locked loop circuit configured to generate an adjusted first divider value for the first phase-locked loop circuit. The clock signal generator further includes a target frequency calculation circuit configured to calculate a target frequency for the second phase-locked loop circuit based on a target frequency ratio of the second phase-locked loop circuit calculated based on frequency offset ratios of the first and second clock signals with respect to a reference signal.

A multi-loop clock signal generator includes a first phase-locked loop circuit configured to generate a control signal and a voltage-controlled oscillator configured to generate an output clock signal based on the control signal. The clock signal generator includes a second phase-locked loop circuit configured to generate an adjusted first divider value for the first phase-locked loop circuit. The clock signal generator further includes a target frequency calculation circuit configured to calculate a target frequency for the second phase-locked loop circuit based on a target frequency ratio of the second phase-locked loop circuit calculated based on frequency offset ratios of the first and second clock signals with respect to a reference signal.

This disclosure is directed to enhancing PLL performance via gain calibration and duty cycle calibration. It may be desirable to perform loop gain and duty cycle calibration simultaneously. However, doing so may result in prohibitive complexity and/or area/power penalty. To enable loop gain calibration and duty cycle calibration simultaneously, the duty cycle error and the gain error may be detected in the time domain, which may enable duty cycle calibration and loop gain calibration circuitries to share a phase detector. Detecting the duty cycle error and the loop gain error in the time domain may be accomplished by implementing an analog or digital PLL system, wherein the loop gain of the PLL system is a function of the input phase offset time.

This disclosure is directed to enhancing PLL performance via gain calibration and duty cycle calibration. It may be desirable to perform loop gain and duty cycle calibration simultaneously. However, doing so may result in prohibitive complexity and/or area/power penalty. To enable loop gain calibration and duty cycle calibration simultaneously, the duty cycle error and the gain error may be detected in the time domain, which may enable duty cycle calibration and loop gain calibration circuitries to share a phase detector. Detecting the duty cycle error and the loop gain error in the time domain may be accomplished by implementing an analog or digital PLL system, wherein the loop gain of the PLL system is a function of the input phase offset time.

This disclosure is directed to PLLs, and, in particular, to enhancing PLL performance via gain calibration. PLL loop gain may vary with respect to process, voltage, and temperature (PVT) variation. To control the PLL loop gain, a gain calibration loop may be implemented. However, calibrating the loop gain by directly measuring the loop gain may be disadvantageous. To reduce or eliminate PLL loop gain variation due to PVT variation, a PLL having a loop gain function that is a function of an input phase offset time with a phase noise performance that remains consistent across PVT variations is disclosed. By determining a relationship between PLL loop gain and phase offset, detecting and calibrating phase offset may result in enhanced calibration of the PLL loop gain, while avoiding the additional difficulty and complexity associated with directly measuring loop gain of a PLL.

This disclosure is directed to PLLs, and, in particular, to enhancing PLL performance via gain calibration. PLL loop gain may vary with respect to process, voltage, and temperature (PVT) variation. To control the PLL loop gain, a gain calibration loop may be implemented. However, calibrating the loop gain by directly measuring the loop gain may be disadvantageous. To reduce or eliminate PLL loop gain variation due to PVT variation, a PLL having a loop gain function that is a function of an input phase offset time with a phase noise performance that remains consistent across PVT variations is disclosed. By determining a relationship between PLL loop gain and phase offset, detecting and calibrating phase offset may result in enhanced calibration of the PLL loop gain, while avoiding the additional difficulty and complexity associated with directly measuring loop gain of a PLL.

Embodiments of the present disclosure disclose a clock frequency detection method and apparatus. The method includes: dividing a known internal clock frequency range of the system into n frequency intervals, where each frequency interval is corresponding to a frequency detection module, and n is an integer greater than or equal to 2; obtaining a current internal clock frequency of the system, and using the current internal clock frequency as a reference clock frequency; selecting a frequency detection module corresponding to a frequency interval according to the reference clock frequency; and detecting, by the selected frequency detection module, a to-be-detected clock according to a frequency offset range of the reference clock frequency. By using the present disclosure, a risk that an internal clock of the system is attacked may be reduced, and system security may be improved.

Embodiments of the present disclosure disclose a clock frequency detection method and apparatus. The method includes: dividing a known internal clock frequency range of the system into n frequency intervals, where each frequency interval is corresponding to a frequency detection module, and n is an integer greater than or equal to 2; obtaining a current internal clock frequency of the system, and using the current internal clock frequency as a reference clock frequency; selecting a frequency detection module corresponding to a frequency interval according to the reference clock frequency; and detecting, by the selected frequency detection module, a to-be-detected clock according to a frequency offset range of the reference clock frequency. By using the present disclosure, a risk that an internal clock of the system is attacked may be reduced, and system security may be improved.