PURPOSE:To prevent a circuit interference from occurring by a method wherein a third electronic circuit region, which does not operate in conjunction with other first and second electronic circuit region, is provided between the first and the second electronic circuit region which operate simultaneously. CONSTITUTION:An FM front end block, an FM-IF block, and an AM turner block are formed on regions 21-23, respectively, where the region 23 surrounds the region 21 and the region 22 is provided to the periphery of the region 23. The region 23 stops operating when the regions 21 and 22 are in operation. Therefore, the region 23 becomes high in impedance, so that the interference between the regions 21 and 22 can be prevented. The AM tuner block itself functions as a huge capacitor, and even if high frequency noises originated from the regions 21 and 22 penetrate into a semiconductor substrate 27, they are absorbed in a power line 28 as the capacitor is provided between the regions 21 and 22, and consequently circuit interference can be prevented.
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