| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a digital filter with excellent compatibility with an analog computing operation at the pre-stage of an analog section, which can form a notch at a noise position to an output from the analog section and can improve noise removal performance. <P>SOLUTION: At the pre-stage of a digital filter 1, an analog section 2 in which a bit data output of an analog computing result changes per four clocks is disposed. The digital filter operates by the clock synchronized with the analog section 2, and removes noise from the bit data that is output from the analog section 2. The digital filter comprises a Sync fourth-power filter 11 in which Sync filters obtaining a moving average of samples are vertically connected in four stages, and a four-tap moving average filter 12 connected to the output stage of the Sync fourth-power filter 11. <P>COPYRIGHT: (C)2012,JPO&INPIT |
