| 摘要 |
A frequency synthesizer is provided to minimize power consumption by having a low jitter component. A frequency synthesizer(100) comprises a phase comparator(10), a charge pumping circuit(20), a voltage control oscillator(30), a duty cycle correction circuit(40), and a feedback divider(50). The phase comparator receives a reference signal and a comparison signal, detects a difference of a phase and a frequency, and generates up signal or down signal. The charge pumping circuit outputs a control signal by charging/discharging a voltage according to the up signal or the down signal. The voltage control oscillator outputs a signal having the frequency as an oscillation output signal according to the control signal outputted from the charge pumping circuit. The duty cycle correction circuit is connected to the voltage control oscillator, and corrects a duty cycle. The feedback divider provides the comparison signal for the phase comparator by dividing a frequency of the oscillation output signal.
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