| 摘要 |
PURPOSE:To prevent the oscillating state from being disturbed by avoiding an output from being outputted externally at the start of oscillation. CONSTITUTION:If no oscillation is started or the oscillation is insufficient in an oscillating circuit 45 at the application of power supply, an output signal 49 of the oscillating circuit 45 is inhibited from being outputted at the outside of an integrated circuit through an output circuit 48 by an output signal 51 of an oscillation detecting circuit 47. Even if there exists a parasitic capacitance among terminals 52, 53, 54, the capacitance is not a cause to disturb the growth of the oscillation of the oscillating circuit 45. When the oscillation is grown sufficiently and the output of the oscillating circuit 45 reaches the oscillation detecting circuit 47 via a frequency dividing circuit 46, an output circuit 48 outputs a signal having the same frequency as the oscillating frequency to a terminal 54. The frequency dividing the oscillating frequency and the oscillation frequency itself are extracted stably at the same time. |
