| 摘要 |
PURPOSE:To simplify a phase synchronizing circuit and also to enable it to operate definitely by combining a primary phase synchronizing circuit and secondary phase synchronizing circuit together. CONSTITUTION:A series circuit of phase comparator 26 and LPF 27 constituting primary phase synchronizing circuit PLL and that of phase comparator 28 and LPF 29 constituting secondary PLL are connected to input terminal 25 and adder 30. Through voltage control oscillator 31 and divider 32, their outputs are led to the inputs of circuits 26 and 28 to constitute a phase synchronizing circuit. Since primary and secondary PLLs are connected in common through adder 30 except phase comparators and LPFs, demerits of two PLLs are compensated by themselves each other. Therefore, an input signal would vary in frequency or phase, follow-up characteristics by an output signal are excellent and those PLLs operate definitely without staionary phase error. |
