FREQUENCY SIGNAL GENERATION SYSTEM AND DISPLAY APPARATUS

摘要

The invention provides a frequency signal generating system and a display device. The frequency signal generating system comprises a digital phase-locked loop for receiving a source frequency signal; a loop filter whose input terminal is connected to an output terminal of the digital phase-locked loop, for filtering out high frequency components of a signal output from the digital phase-locked loop; and a voltage controlled oscillator whose input terminal is connected to an output terminal of the loop filter, for outputting a target frequency signal according to a signal from the loop filter, wherein an output terminal of the voltage controlled oscillator is connected to a first output terminal of the digital phase-locked loop so that the target frequency signal output from the voltage controlled oscillator is fed back to the digital phase-locked loop, the digital phase-locked loop performs frequency-dividing and phase-detecting on the source frequency signal and the fed back target frequency signal so that the target frequency signal output from the voltage controlled oscillator and the source frequency signal satisfy a definite mathematical relationship therebetween. Through combination of the analog circuits and the digital circuits, the frequency signal generating system can generate a target frequency signal which can be accurately controlled, and cost of the system is largely reduced.