| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress current consumption while suppressing the mounting area of a noise canceling circuit. Ž<P>SOLUTION: The noise canceling circuit 50 includes: an A/D converting circuit 56 which converts an analog signal n1 output from a speaker 70 into a digital noise signal dn; a digital signal receiver 51 to which a multiplex digital audio signal dX with a first digital audio signal dL and a second digital audio signal dR multiplexed thereto is supplied from outside, and which separates and outputs one digital audio signal; a DSP which generates a driving digital signal dT by performing an arithmetic operation so as to cancel external noise; and a class D amplifying circuit 55 which drives the speaker 70 according to a control signal P having a pulse width corresponding to the driving digital signal dT. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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