| 摘要 |
PURPOSE:To improve high speed performance for establishing synchronization and stability in a steady-state by varying a conversion gain coefficient of a phase comparator section in multistage from a larger to a smaller coefficient according to the elapse of time and varying the loop gain of a loop filter section from a smaller to a larger gain according to the change in the conversion gain coefficient. CONSTITUTION:The system consists of a phase comparator section 1, a loop filter section 2 and a digital VCO section 3. The conversion gain coefficient K1 of a multiplier 1-2 in the phase comparator section 1 is changed from a larger value to a smaller value as the elapse of time and the loop filter 2 is provided with a multiplier 2-3 and an adder 2-4 to change the loop gain K2 from a small to a large value corresponding to the change in the conversion gain coefficient K1. Thus, the high speed performance for establishing synchronization and the stability in the steady-state obtained by controlling the gain conversion characteristic K1 are further improved. |
