| 摘要 |
PURPOSE:To obtain a phase comparison output with high accuracy by obtaining a phase difference of a pulse formed by a one-shot pulse generating circuit so as to cancel the process dispersion in the pulse width from the generating circuit when a signal to be compared is retarded to the comparison signal. CONSTITUTION:A 1st pulse A having a prescribed time width is generated from a reference edge of the comparison signal F1 is generated in 1st and 2nd one-shot pulse generating circuits MB1, MB2 and a 2nd pulse C set to the constant time similar to the one-shot pulse A synchronously with the front edge of the signal F2 to be compared generated intermittently within a time being a half period from the reference edge is generated. While the 2nd pulse C is outputted, the difference of the back edges of the 1st and 2nd pulses A, C is obtained by a 1st flip-flop circuit FF1 whose operation is made effective. Thus, since the process dispersion in the pulse width in the one-shot pulse generating circuits MB1, MB2 is canceled, the phase comparison output with high accuracy is obtained. |
