| 摘要 |
PURPOSE:To make a PLL frequency synthesizer compact by composing a circuit which forcibly makes PLL in-phase of a digital circuit suitable for LSI. CONSTITUTION:The PLL frequency synthesizer is composed of a phase comparator 2, loop filter 3, voltage controlled oscillator 4 and variable frequency divider 5 and to these parts, a synchronization detector 6 and a frequency dividing ratio control circuit 8 are added for the PLL to forcibly make the PLL in-phase at the time of being in non in-phase state. The circuit for this PLL to forcibly make the PLL the in-phase state at the time of being in non in-phase state can be composed of the digital circuit suitable for LSI. Thus, the PLL frequency synthesizer can be made compact. |
