| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide the waveform shaping circuit that keeps a duty ratio constant, regardless of the fluctuations in repeating periods of an input signal. SOLUTION: A 1st charging circuit 2 charges/discharges a 1st capacitor 8, and a 2nd charging circuit 3 charges/discharges a 2nd capacitor 9 alternatively, in synchronous with an input signal frequency-divided into a half by a frequency divider 1. On the other hand, a comparator 4 that makes voltage comparison of the 1st and 2nd capacitors 8, 9 and a control circuit 5, that is operated in response to an output signal of the frequency divider 1, make a 1st reset switch 6 and a 2nd reset switch 7 conductive alternately in a prescribed timing to reset the 1st and 2nd capacitors 8, 9. As a result, a signal with a preset duty not affected by fluctuations in repeating periods of an input signal is obtained from the output of an OR circuit 10.</p> |
