| 摘要 |
PROBLEM TO BE SOLVED: To obtain a power supply controller in consideration of power supply efficiency while preventing deterioration in reception performance of an SN ratio or the like, when receiving radio broadcasting or television broadcasting due to switching noise. SOLUTION: A switching control circuit 8a operates a switching regulator 1a after selecting the switching regulator 1a excellent in power supply efficiency by turning on a switching circuit 1c1 for a switching regulator when an S meter value VS signal from a radio tuner 2 exceeds a preset reference value Va, or when it is less than a reference value Vb(<Va), and also, selects a series regulator 1b by turning on a switching circuit 1c3 for a series regulator when the S meter value VS signal from the radio tuner 2 is below the reference value Va. Consequently, it is possible to prevent the deterioration in reception performance when receiving broadcasting due to the switching noise. COPYRIGHT: (C)2007,JPO&INPIT
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