| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a filter circuit capable of preventing enlargement of the circuit and restraining cost even when variation width of a filter characteristic is narrow and the range thereof is wide. <P>SOLUTION: An element value of at least one kind of element 3, which determines a filter characteristic of this filter circuit 2, is varied based on the output of aΣΔmodulator 1, which sigma-delta modulates a digital code input (Code) based on an operation clock CLK, or a signal through a decoder 4 which performs a code-conversion to the output of theΣΔmodulator 1. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
