| 摘要 |
PURPOSE:To make a titled system small in size, to reduce power consumption, and also to stabilize the frequency by switching a control voltage of a voltage control oscillator, a frequency dividing input, a frequency dividing ratio of a frequency divider, and a cut-off characteristic of an LPF, by a changeover switch, and using the frequency divider in common. CONSTITUTION:In case a switching control device SW.CONT is selecting a voltage control oscillator OSC1, an output of an LPF.LPFa is connected to a voltage holding circuit HOLD1 through a changeover switch SW, and an output of the oscillator OSC1 is connected to a frequency divider DIVa through the switch SW. Also, the device SW.CONT controls the frequency divider DIVa, and sets it to a frequency dividing ratio of the frequency divider DIVa which can obtain the almost same output frequency as an output frequency of a frequency divider DIV. Moreover, the device SW.CONT controls the LPF.LPFa, and sets a characteristic of the LPF.LPFa so as to have an appropriate cut-off characteristic in said state. |
