A device for synchronizing a periodic high frequency power signal (18) and an external reference signal (10). The device comprises a phase control circuit (100) and a digital oscillator circuit (130). The digital oscillator circuit (130) is connected to the phase control circuit (100). The digital oscillator circuit (130) comprises means for generating the periodic high frequency power signal (18) dependent on the control signal from the phase control circuit. The phase control circuit (100) is configured to determine a phase difference of the periodic high frequency power signal (18) and the external reference signal (10).

A phase locked loop circuit includes a phase comparator that compares phases of a reference signal through a first frequency divider and a local signal through a second frequency divider to output a phase comparison signal; a loop filter that smooths the phase comparison signal to output the control voltage signal; a controller that sets frequency division ratios of the first and the second frequency dividers; a free-running voltage generator that generates a free-running voltage signal of the voltage control oscillator; a measurement circuit that measures a voltage of the control voltage signal; a storage circuit that stores therein the voltage of the control voltage signal; and a low-pass filter that transmits, to the voltage control oscillator, a corrected free-running voltage signal based on a free-running voltage correction value calculated by the free-running voltage generator based on the control voltage signal before the frequency division ratios are changed.

A phase locked loop circuit includes a phase comparator that compares phases of a reference signal through a first frequency divider and a local signal through a second frequency divider to output a phase comparison signal; a loop filter that smooths the phase comparison signal to output the control voltage signal; a controller that sets frequency division ratios of the first and the second frequency dividers; a free-running voltage generator that generates a free-running voltage signal of the voltage control oscillator; a measurement circuit that measures a voltage of the control voltage signal; a storage circuit that stores therein the voltage of the control voltage signal; and a low-pass filter that transmits, to the voltage control oscillator, a corrected free-running voltage signal based on a free-running voltage correction value calculated by the free-running voltage generator based on the control voltage signal before the frequency division ratios are changed.

A successive-approximation register (SAR) analog-to-digital converter (ADC) circuit includes a comparator circuit and a plurality of latch circuits. The comparator circuit is configured to compare an analog signal with a plurality of reference levels. The latch circuits, coupled to the comparator circuit and connected in series, are triggered sequentially in response to a plurality of trigger signals, respectively, to store a comparator output of the comparator circuit and accordingly generate a digital signal. A first latch circuit and a second latch circuit of the latch circuits are triggered in response to a first trigger signal and a second trigger signal of the trigger signals, respectively. The first latch circuit is configured to generate the second trigger signal according to the comparator output stored in the first latch circuit.

A successive-approximation register (SAR) analog-to-digital converter (ADC) circuit includes a comparator circuit and a plurality of latch circuits. The comparator circuit is configured to compare an analog signal with a plurality of reference levels. The latch circuits, coupled to the comparator circuit and connected in series, are triggered sequentially in response to a plurality of trigger signals, respectively, to store a comparator output of the comparator circuit and accordingly generate a digital signal. A first latch circuit and a second latch circuit of the latch circuits are triggered in response to a first trigger signal and a second trigger signal of the trigger signals, respectively. The first latch circuit is configured to generate the second trigger signal according to the comparator output stored in the first latch circuit.

A phase locked loop circuit includes a phase comparator that compares phases of a reference signal through a first frequency divider and a local signal through a second frequency divider to output a phase comparison signal; a loop filter that smooths the phase comparison signal to output the control voltage signal; a controller that sets frequency division ratios of the first and the second frequency dividers; a free-running voltage generator that generates a free-running voltage signal of the voltage control oscillator; a measurement circuit that measures a voltage of the control voltage signal; a storage circuit that stores therein the voltage of the control voltage signal; and a low-pass filter that transmits, to the voltage control oscillator, a corrected free-running voltage signal based on a free-running voltage correction value calculated by the free-running voltage generator based on the control voltage signal before the frequency division ratios are changed.

A phase locked loop circuit includes a phase comparator that compares phases of a reference signal through a first frequency divider and a local signal through a second frequency divider to output a phase comparison signal; a loop filter that smooths the phase comparison signal to output the control voltage signal; a controller that sets frequency division ratios of the first and the second frequency dividers; a free-running voltage generator that generates a free-running voltage signal of the voltage control oscillator; a measurement circuit that measures a voltage of the control voltage signal; a storage circuit that stores therein the voltage of the control voltage signal; and a low-pass filter that transmits, to the voltage control oscillator, a corrected free-running voltage signal based on a free-running voltage correction value calculated by the free-running voltage generator based on the control voltage signal before the frequency division ratios are changed.

A successive-approximation register (SAR) analog-to-digital converter (ADC) circuit includes a comparator circuit and a plurality of latch circuits. The comparator circuit is configured to compare an analog signal with a plurality of reference levels. The latch circuits, coupled to the comparator circuit and connected in series, are triggered sequentially in response to a plurality of trigger signals, respectively, to store a comparator output of the comparator circuit and accordingly generate a digital signal. A first latch circuit and a second latch circuit of the latch circuits are triggered in response to a first trigger signal and a second trigger signal of the trigger signals, respectively. The first latch circuit is configured to generate the second trigger signal according to the comparator output stored in the first latch circuit.

A successive-approximation register (SAR) analog-to-digital converter (ADC) circuit includes a comparator circuit and a plurality of latch circuits. The comparator circuit is configured to compare an analog signal with a plurality of reference levels. The latch circuits, coupled to the comparator circuit and connected in series, are triggered sequentially in response to a plurality of trigger signals, respectively, to store a comparator output of the comparator circuit and accordingly generate a digital signal. A first latch circuit and a second latch circuit of the latch circuits are triggered in response to a first trigger signal and a second trigger signal of the trigger signals, respectively. The first latch circuit is configured to generate the second trigger signal according to the comparator output stored in the first latch circuit.

A device for synchronizing a periodic high frequency power signal (18) and an external reference signal (10). The device comprises a phase control circuit (100) and a digital oscillator circuit (130). The digital oscillator circuit (130) is connected to the phase control circuit (100). The digital oscillator circuit (130) comprises means for generating the periodic high frequency power signal (18) dependent on the control signal from the phase control circuit. The phase control circuit (100) is configured to determine a phase difference of the periodic high frequency power signal (18) and the external reference signal (10).