| 摘要 |
PURPOSE:To make accurate the detection of the leading (trailing) position of an input signal, by shaping two threshold levels different in height and by subjecting the difference output thereof and the output of one of threshold circuits to AND processing respectively. CONSTITUTION:An input signal (a) is supplied to first and second threshold circuits 102 and 104 having levels different in height, through an amplifier circuit 100. First and second FFs 106 and 108 are set by the outputs (c) and (d) of said circuits 102 and 104 and reset by a synchronous signal (e), and the square wave gate signals (f) and (g) thereof are inputted to a third FF110. Then a compensated gate signal (h) of FF110, a clock signal (i), the signal (g) and a clock signal (k) are inputted to first and second gates 112 and 114, and a compensated pulse signal (j) and an output pulse signal l are added up by an OR gate 116. On the occasion, the ratio in period between the signals (i) and l is made to correspond with the ratio of the level of the circuit 102 to the difference between the levels of the circuits 102 and 104, and based thereon, a leading (trailing) position is presumed. |
