| 摘要 |
PURPOSE:To enable a frequency control with a high accuracy by constituting one or both of first and second frequency divider circuits dividing a reference frequency from synchronous frequency divider circuits and by setting the dividing ratio of at least one of said two frequency divider circuits to a value other than 2<n>. CONSTITUTION:A first frequency divider circuit 1 starts dividing a reference frequency from a reference oscillation circuit 4 by FG input signal, and a second frequency divider circuit 2 starts dividing a reference frequency from a reference oscillation circuit 4 by the output of the first frequency divider circuit 1. The output of the first and second frequency divider circuits 2 is inputted to AND element 5 and NOR element 6 and transistors Tr3, Tr1 are controlled by the output of said elements. A frequency control signal is derived from the collector of said transistor Tr3. One or both of dividing ratios of the first and second frequency divider circuits 1, 2 are set to a value other than 2<n> and at least one of the first and second frequency divider circuits 1, 2 is constituted by a synchronous frequency divider circuit. |
