| 摘要 |
PURPOSE:To obtain a phase detector having good linearity by combining two phase detecting circuits being unstable around zero output, giving a delay to one input, coupling output terminals of opposite polarities with each other in both phase detecting circuits and extracting the output signal after smoothing. CONSTITUTION:A reference pulse A is inputted to an input terminal 25 of phase detecting circuits 22, 23, and a pulse B frequency-dividing an output of a voltage controlled oscillator 36 by a frequency division circuit 37 (with a delay circuit 26 to one input) is inputted to the other input terminal 1. A signal shown in Fig. D is inputted to a smoothing circuit 28 which is connected to a delay phase output terminal 5 of a phase detecting circuit 22 inputted with a pulse C via the delay circuit 26 and to a lead phase output terminal 10 of the other phase detecting circuit 23, and a voltage shown in Fig. E is outputted. As a result, the output characteristic as shown in the line 41 is obtained, in which the linearity aruond zero level is improved. |
