| 摘要 |
PURPOSE:To improve the accuracy of an oscillator by digitizing a phase comparator and a loop filter. CONSTITUTION:A frequency divider 10 divides a transmitted sampling clock, a frequency divider 7 divides a transmission line clock and a comparator 8 compares these divided results to prepare staff information. In the receiving side, a shift register 26 inputs the staff information, a code converter 27 converts the staff information into relative information, a frequency divider 35 divides the transmission clock, and a counter 29 prepares relative information from the divided result and the received sampling clock. A subtractor 30 finds out the difference between these relative information, the result is inputted to a register 31 a limiter 32 limits the amplitude, a digital filter 33 smoothes the limited signal, and a D/A converter 34 converts the digital signal into an analog signal to control a voltage controlling oscillator 28. |
