TWO-CIRCUIT NETWORK FOR AUTOMATIC PHASE LOCK CONTROL AND CHROMATICITY SIGNAL DEMODULATION CIRCUIT USING TWO-CIRCUIT NETWORK FOR AUTOMATIC PHASE LOCK CONTROL Russian patent published in 2003 - IPC

FIELD: radio engineering. SUBSTANCE: invention refers to automatic phase lock control network generating clock discretization signal synchronized by phase with signal of chromaticity synchronization and to demodulation network of chromaticity signal. Technical result of invention consists in development of automatic phase lock control network changing phase of clock discretization signal for analog-to-digital conversion and demodulation circuit of chromaticity signal demodulating chroma signal with high accuracy with use of two-circuit network for automatic phase lock control. To achieve this result two-circuit network is provided with circuits of fixation, analog-to-digital conversion, output of reference signal of chromaticity synchronization and phase detection which gives possibility to convert clock discretization signal generated by automatic phase lock control network to analog-to-digital conversion circuit to signal with frequency N•F_SC synchronized by phase with chromaticity synchronization signal and to change continuously phase of signal in correspondence with value of reference phase. Demodulation circuit converts output signal of analog-to-digital conversion circuit to chroma signal. EFFECT: high- accuracy demodulation of chroma signal with use of automatic phase lock control network. 17 cl, 9 dwg