摘要 |
<p>An automatic adjustment circuit comprises a replica (1) constituted of either a circuit block of a portion of a filter body (3) or a combination of the circuit block, and fed with a reference signal (2) from the outside, for outputting signals having a phase delays of 90 degrees and 180 degrees with respect to the reference signal (2), and an integrating comparator (4) fed at its input terminal with an output signal, as having a phase delay of 180 degrees, of the replica (1) and the reference signal (2), and at its clock terminal with an output signal, as having a phase delay of 90 degrees, of the replica (1), and having an output terminal connected with a capacity (C1) and a frequency characteristic adjusting terminal of the replica (1). The automatic adjusting circuit is characterized in that the integrating action of the integrating comparator (4) is performed across the two high/low states of the input signal.</p> |