PLL circuit having a multiloop, and FM receiving method and apparatus
able to utilize the same
    1.
    发明授权
    PLL circuit having a multiloop, and FM receiving method and apparatus able to utilize the same 失效
    具有多回路的PLL电路以及能够利用它的FM接收方法和装置

    公开(公告)号:US5517685A

    公开(公告)日:1996-05-14

    申请号:US227125

    申请日:1994-04-13

    CPC分类号: H03L7/087

    摘要: The PLL circuit provides both the advantages of analog phase control, in which a good C/N ratio can be realized, and the advantages of digital phase control, in which broad-band lock can be performed. A multi-channel FM receiving method and apparatus are able to utilize the PLL circuit to reduce the influence of the leakage occurring among input signals and suppress image disturbance. One PLL circuit includes: a VCO; a pre-scaler for dividing a feedback signal obtained from the VCO; a first distributor for distributing the feedback signal to send first and second digital feedback signals; a second distributor for distributing a reference signal to send a digital reference signal and an analog reference signal; a digital phase comparator for comparing the digital reference signal and the first digital feedback signal with each other to send a digital phase error signal; a charge pump; a mixer for adding the digital phase error signal to an analog phase error signal, which is obtained by comparing the analog reference signal with the second digital feedback signal to send a composite phase error signal; and a low-pass filter for eliminating high frequency components from the composite phase error signal to input the resultant signal to the VCO.

    摘要翻译: PLL电路既提供了可实现良好的C / N比的模拟相位控制的优点,也可以进行宽带锁定的数字相位控制的优点。 多通道FM接收方法和装置能够利用PLL电路来减少输入信号之间发生的泄漏的影响并抑制图像干扰。 一个PLL电路包括:VCO; 用于分割从VCO获得的反馈信号的预定标器; 用于分配反馈信号以发送第一和第二数字反馈信号的第一分配器; 用于分配参考信号以发送数字参考信号和模拟参考信号的第二分配器; 数字相位比较器,用于将数字参考信号和第一数字反馈信号彼此进行比较以发送数字相位误差信号; 电荷泵; 混频器,用于将数字相位误差信号加到模拟相位误差信号上,模拟相位误差信号通过将模拟参考信号与第二数字反馈信号进行比较而发送复合相位误差信号; 以及用于从复合相位误差信号中消除高频分量的低通滤波器,以将所得到的信号输入到VCO。