| 摘要 |
PROBLEM TO BE SOLVED: To provide a gain control circuit which can input a signal over a power supply voltage and can vary the setting range of the gain. SOLUTION: The gain control circuit is operated with a single power supply and has an amplifier 30 capable of varying the gain. The gain control circuit has a plurality of input terminals 100 and 101, one ends of each of a plurality of resistance elements R1 and R2 having weighted resistance values are connected to each of a plurality of the input terminals, the other ends of a plurality of the resistance elements are commonly connected, the common connection point is connected to the input side of a variable resistance circuit 12 for varying the gain and the signal can be input to all of a plurality of the input terminals or to a part of a plurality of the input terminals. COPYRIGHT: (C)2003,JPO
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