| 摘要 |
PROBLEM TO BE SOLVED: To reduce the IC chip size and package size of a tuner for FM data broadcasting. SOLUTION: Adjacent disturbance is detected by using an IF counter 74 which is used for a seek search for a broadcasting station, and then the need for an extra circuit for adjacent disturbance detection is eliminated, enabling size reduction. The IF counter 74 counts the frequency of an intermediate signal obtained by frequency-converting a reception signal. A counted value N is input to a control unit 54. Once the adjacent disturbance is received, the counted value N becomes different from a value n<SB>IF</SB>corresponding to an original intermediate frequency f<SB>IF</SB>. The control unit 54 decides that the adjacent disturbance has occurred, when the deviation amount thereof exceeds a predetermined allowable errorδn. COPYRIGHT: (C)2009,JPO&INPIT
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