| 摘要 |
<p>A selector (5) is switched to generate a learning signal (B) by a signal generator (4) and supply it to a filter (1) used in an actual operation. The learning signal (B) supplied to the filter (1) is supplied subjected to filter processing and supplied to a signal amplitude detector (2) to measure the output value. After this, in DSP (3) an operation process is executed according to the output value measured by the signal amplitude detector (2) and a cut-off frequency of the filter (1) is adjusted to a desired value. Accordingly, it is possible to provide a filter circuit satisfying system specification even when using an analog circuit element having small circuit element irregularities as a constituent element and to effectively learn a cut-off frequency without increasing the layout area as compared to the prior art.</p> |
