| 摘要 |
PROBLEM TO BE SOLVED: To provide a DTMF detection device capable of preventing misdetection due to level monitoring of an input signal. SOLUTION: A DTMF detection circuit 10 supplies an averaged level 26 obtained as a measurement result from a level detection circuit 18 to a DTMF decision control circuit 20, which compares the level 26 with a threshold to generate and supplies a control signal 28 to the DTMF decision circuit 16 to control the DTMF decision circuit 16, so as to operate the DTMF decision circuit 16 according to the quality of a digital signal. COPYRIGHT: (C)2006,JPO&NCIPI
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