Apparatus for synchronizing phases of clocks generated by dual clock units in synchronous transmission system

摘要

PURPOSE: A clock phase synchronization device between dual clock units of a synchronous transmission system is provided to match effectively phases of each system clock by exchanging phase detection data of phase synchronous loops between dual clock units of a transmission system. CONSTITUTION: A master unit is formed with a digital phase detector(320), a comparison decision portion(321), a digital loop filter(322), a DAC(323), and a VCXO(324). A slave unit is formed with a digital phase detector(310), a comparison decision portion(311), a digital loop filter(312), a DAC(313), and a VCXO(314). The master unit and the slave unit receives and transmits phase detection data of the digital phase detectors(310,320) from or to each other in order to match phases of output clocks of the VCXO(314,324) of the master unit or the slave unit.