FREQUENCY SIGNAL GENERATION SYSTEM AND DISPLAY APPARATUS

摘要

The present invention provides a frequency signal generation system and a display apparatus. The system comprises: a digital phase-locked loop which receives a source frequency signal; a loop filter, an input end of which is connected to an output end of the digital phase-locked loop, and which is used for filtering out a high-frequency component signal among signals output by the phase-locked loop; and a voltage-controlled oscillator, an input end of which is connected to an output of the loop filter, and which is used for outputting a target frequency signal according to a signal from the loop filter. An output end of the voltage-controlled oscillator is connected to a first input end of the digital phase-locked loop, so that the target frequency signal output by the voltage-controlled oscillator is fed back to the digital phase-locked loop; the digital phase-locked loop separately performs frequency division and phase discrimination on the source frequency signal and the fed-back target frequency signal, so that a determined mathematical correspondence exists between the target frequency signal output by the voltage-controlled oscillator and the source frequency signal. By means of mixture of an analog circuit and a digital circuit, the system can generate an accurate and controllable target frequency signal and can greatly reduce cost of the system.