A semiconductor device includes a clock generator which receives an input clock and generates an output clock, a reference voltage generator which receives the input clock or the output clock, generates a sub-reference voltage in accordance with a frequency of the input clock or a frequency of the output clock, and generates a reference voltage using the sub-reference voltage and a preset error voltage, and a clock detector which receives the output clock, generates a first output voltage in accordance with the output clock, and compares the generated first output voltage with the reference voltage to output an error signal based on the output clock, wherein the preset error voltage is set in accordance with a degree of preset error of the output clock.

An electronic device may include a transceiver with mixer circuitry that up-converts or down-converts signals based on a voltage-controlled oscillator (VCO) signal. The transceiver circuitry may include first, second, third, and fourth VCOs. Each VCO may include a VCO core that receives a control voltage and an inductor coupled to the VCO core. Fixed linear capacitors may be coupled between the VCO cores. A switching network may be coupled between the VCOs. Control circuitry may place the VCO circuitry in one of four different operating modes and may switch between the operating modes to selectively control current direction in each of the inductors. The VCO circuitry may generate the VCO signal within a respective frequency range in each of the operating modes. The VCO circuitry may exhibit a relatively wide frequency range across all of the operating modes while introducing minimal phase noise to the system.

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 clock signal generating circuit includes a detecting circuit configured to generate a first voltage based on first and second clock signals and adjust a level of the first voltage in response to first and second setup voltages and a resistance variable code, a comparing circuit configured to compare the first voltage and a reference voltage and output a check signal according to a comparison result, a code generating circuit configured to perform a first modulation operation for determining the resistance variable code in response to the check signal and perform a second modulation operation for determining a control code in response to the check signal, and an oscillator configured to adjust an amplitude of the first and second clock signals in response to the control code, and output the first and second clock signals having the adjusted amplitude.

A clock signal generating circuit includes a detecting circuit configured to generate a first voltage based on first and second clock signals and adjust a level of the first voltage in response to first and second setup voltages and a resistance variable code, a comparing circuit configured to compare the first voltage and a reference voltage and output a check signal according to a comparison result, a code generating circuit configured to perform a first modulation operation for determining the resistance variable code in response to the check signal and perform a second modulation operation for determining a control code in response to the check signal, and an oscillator configured to adjust an amplitude of the first and second clock signals in response to the control code, and output the first and second clock signals having the adjusted amplitude.

A semiconductor device outputs, as an output signal synchronized to a phase-locked loop clock signal, a synchronized input signal that is synchronized to a reference clock signal of a phase-locked loop circuit. The semiconductor device includes the phase-locked loop circuit, a first flip-flop that receives the input signal in synchronization with the reference clock signal on the basis of a feedback signal inputted to a phase comparator of the phase-locked loop circuit 10, and a second flip-flop that receives an output from the first flip-flop on the basis of the phase-locked loop clock signal. The second flip-flop outputs the output from the first flip-flop as the output signal. A setup time to synchronize the input signal to the phase-locked loop clock signal is set to one half of a period of the reference clock signal.

A semiconductor device outputs, as an output signal synchronized to a phase-locked loop clock signal, a synchronized input signal that is synchronized to a reference clock signal of a phase-locked loop circuit. The semiconductor device includes the phase-locked loop circuit, a first flip-flop that receives the input signal in synchronization with the reference clock signal on the basis of a feedback signal inputted to a phase comparator of the phase-locked loop circuit 10, and a second flip-flop that receives an output from the first flip-flop on the basis of the phase-locked loop clock signal. The second flip-flop outputs the output from the first flip-flop as the output signal. A setup time to synchronize the input signal to the phase-locked loop clock signal is set to one half of a period of the reference clock signal.

A semiconductor device outputs, as an output signal synchronized to a phase-locked loop clock signal, a synchronized input signal that is synchronized to a reference clock signal of a phase-locked loop circuit. The semiconductor device includes the phase-locked loop circuit, a first flip-flop that receives the input signal in synchronization with the reference clock signal on the basis of a feedback signal inputted to a phase comparator of the phase-locked loop circuit 10, and a second flip-flop that receives an output from the first flip-flop on the basis of the phase-locked loop clock signal. The second flip-flop outputs the output from the first flip-flop as the output signal. A setup time to synchronize the input signal to the phase-locked loop clock signal is set to one half of a period of the reference clock signal.

A semiconductor device outputs, as an output signal synchronized to a phase-locked loop clock signal, a synchronized input signal that is synchronized to a reference clock signal of a phase-locked loop circuit. The semiconductor device includes the phase-locked loop circuit, a first flip-flop that receives the input signal in synchronization with the reference clock signal on the basis of a feedback signal inputted to a phase comparator of the phase-locked loop circuit 10, and a second flip-flop that receives an output from the first flip-flop on the basis of the phase-locked loop clock signal. The second flip-flop outputs the output from the first flip-flop as the output signal. A setup time to synchronize the input signal to the phase-locked loop clock signal is set to one half of a period of the reference clock signal.