在数字式频率合成器中,程序分频器位于压控振荡器和鉴相器之间,通常鉴相频率远较压控振荡器的工作频率低。因此,在数字式频率合成器中,程序分频器的第一个作用是将压控振荡器的频率降低到鉴相器的频率附近,以便在鉴相器内与参考频率比相,利用其所产生的误差信号来纠正压控振荡器的频率,使其与环路锁定后,压控振荡器的频率为参考频率的 In the digital frequency synthesizer, the program divider is located between the voltage-controlled oscillator and the phase detector, usually the phase frequency is much lower than the operating frequency of the voltage-controlled oscillator. Therefore, in the digital frequency synthesizer, the first function of the program frequency divider is to lower the voltage of the voltage-controlled oscillator to the frequency of the phase detector for comparison with the reference frequency in the phase detector, The resulting error signal to correct the voltage-controlled oscillator frequency, locked with the loop, the voltage-controlled oscillator frequency of the reference frequency