| 摘要 |
PURPOSE:To control two voltage control oscillators with a single phase locked loop by supplying the output of a phase comparator to plural voltage control oscillators via an LPF and driving these oscillators. CONSTITUTION:A TV frequency is applied to a counter 18 via a prescaler counter 17, and an FM frequency is applied directly to the counter 18. Then a switch 29 is controlled to select the frequency of a voltage control oscillator 24 or 25. The output of the counter 18 is applied to a phase comparator 21. One of the control voltages 26 of said output is applied directly to the oscillator 24 via an LPF22, and the other voltage 26 is applied to the oscillator 25 via an impedance separating circuit 23. |
