| 摘要 |
PROBLEM TO BE SOLVED: To provide a filter and semiconductor integrated circuit device in which circuit design can be easily performed in a small circuit scale, regarding the filter and the semiconductor integrated circuit device capable of switching frequency characteristics. SOLUTION: The present invention relates to a filter (100:200) comprising a plurality of stages of filter circuits (111, AMP 11/112, AMP 12;113, AMP 13:211, 212 and AMP 21) and capable of switching required frequency characteristics. In the plurality of stages of filter circuits (111, AMP 11/112, AMP 12;113 and AMP 13), filter circuits (111, AMP 11/112 and AMP 12) of which the quality factor Q is greater than a fixed value are provided as many as a number corresponding to required frequency bands (fc1, fc2), and connections of the filter circuits (111, AMP11/112, AMP 12:211, 212, AMP 21) are switched in accordance with the required frequency bands (fc1, fc2). COPYRIGHT: (C)2008,JPO&INPIT
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