| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem of a conventional oscillation stop detection circuit that has had an increased ratio of a charging/discharging current in its delay circuit to a consumed current of the entire oscillation stop detection circuit and has furthermore increased the consumed current when the operating frequency is increased to enhance the detection accuracy. SOLUTION: The oscillation stop detection circuit is provided with two charging/discharging circuits 10a, 10b connected in parallel and reaching different states of charging and discharging with respect to the same input signal and with an OR circuit 15 that receives output signals from the two charging/ discharging circuits 10a, 10b and provides a different output level between an oscillating state and a non-oscillating state for the detection of the oscillating state and the non-oscillating state. Since the oscillation stop detection circuit employs no delay circuit, this circuit is operated with low power consumption even when adopting an increased detection frequency to logically detect the states.
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