| 摘要 |
PURPOSE:To provide a synchronizing pulse generating circuit capable of obtaining a stable synchronizing pulse with smaller jitter for an external trigger pulse. CONSTITUTION:An oscillation output from a crystal oscillator 1 is phase-shifted by 90 deg. through a 90 deg. phase shifter 2, the oscillation output of the oscillator 1 is sampled/held and binarized by a sampling and holding circuit 3 and a comparator 5 synchronously with an external trigger pulse and the output of the phase shifter 2 is sampled/held and binarized by a sampling and holding circuit 4 and a comparator 6. In any one of phase ranges obtained by dividing one period of the oscillation output from the oscillator 1 into four, whether an external trigger pulse is inputted or not is judged by an external trigger pulse input time judging circuit 8 and one of both binary outputs is selected by a selector 7 and sent as a synchronizing pulse. |
