| 摘要 |
A SECAM system chrominance signal demodulator including a reference oscillator for generating a clock signal, a control signal generator for generating a plurality of clock signals in a time sharing manner, by receiving a synchronizing signal of video signal, a reference frequency generator for generating different reference frequency signals, which is comprised of a DDS circuit for accumulating clock signals generated in the reference oscillator, of which the overflow cycle of the accumulation is changeable under the control of the control signal applied thereto in the time-sharing manner and a D/A converter for converting the accumulated data from the DDS circuit into an analog signal, an adjusting-subject comprising a bell filter for inversely bell-filtering the SECAM system chrominance signal and a chrominance demodulator for demodulating a chrominance signal from an output of the bell filter, and a frequency adjuster for adjusting the frequency by applying the output signal from the D/A converter to the adjusting-subject. <IMAGE> |
