Voltage controlled oscillator adjusting circuit and automatic fine tuning adjusting circuit of television, voltage controlled oscillator and automatic fine tuning adjusting circuit

摘要

In the present invention, a microcomputer performs fine adjustment of an oscillation frequency of a voltage controlled oscillator (VCO) for image detection in a television receiver circuit and an automatic fine tuning (AFT) frequency for fine tuning control of channel tuning. The present invention relates to a voltage controlled oscillator adjusting circuit, an automatic fine tuning adjusting circuit, a voltage controlled oscillator and an automatic fine tuning adjusting circuit, which enable the automatic adjustment of the voltage controlled oscillator or the automatic fine tuning frequency with a digital control value.;Conventional voltage controlled oscillator adjustment or automatic fine tuning adjustment work is inconvenient because it relies on manual work, and requires separate equipment for checking the adjustment state, and there is a problem in that compensation due to changes in the adjustment state over time is impossible. .;According to the present invention, in order to solve the above-mentioned problems, the microcomputer determines whether the voltage controlled oscillator oscillates at a preset reference frequency and whether the automatic fine tuning detection is performed at the preset center voltage level. Circuit parameters that determine the oscillation frequency of the voltage-controlled oscillator in accordance with the control circuit. A voltage controlled oscillator adjustment circuit of a television is provided.