| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reduce influence on a signal processing circuit by the ripple of a power supply voltage. <P>SOLUTION: A first signal processing circuit 10 performs predetermined signal processing on a first signal S1 to provide a change to a characteristic value thereof, and then outputs a second signal S2. A second signal processing circuit 12 performs predetermined signal processing on the second signal S2 to provide a change to a characteristic value thereof, and then outputs a third signal S3. A first and a second switching power supplies 20 and 22 respectively supply power supply voltages Vdd1 and Vdd2 to the first and second signal processing circuits 10 and 12. An amount of change provided to the characteristic value of the first signal S1 by the first signal processing circuit 10, and an amount of change provided to the characteristic value of the second signal S2 by the second signal processing circuit 12, are dependent on the respective power supply voltages Vdd1 and Vdd2. Phases of the first and the second switching power supplies 20 and 22 are respectively set such that an error between the amount of change in the characteristic value of the first signal S1 and its target value, and an error between that of the second signal S2 and its target value, are to be canceled out by each other. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
