| 摘要 |
PURPOSE:To actuate assuredly a one-shot circuit by providing separately an RS latch which gives positively a delay to the signal having a desired frequency and using the output signal of the RS latch as a frequency signal for the one-shot circuit. CONSTITUTION:A part of a frequency dividing circuit is provided with FFs 12- 15. A signal R1 is set ahead of a signal S1 by the time equivalent to delays of three FFs and therefore an RS latch circuit set separately from a one-shot circuit 20 is assuredly actuated to deliver a signal S2 having a delay of a negative edge of the signal S1 by an amount equivalent to the pulse width of the signal R1. The circuit 20 produces a signal T2 from signals S2 and R2 which are delayed sufficiently by an RS latch 3 and through an RS latch 4 and then produces a one-shot signal. In this way, the possibility of a malfunction is eliminated. Furthermore the pulse width is equal to the signal R2 by an AND gate 5. |
