| 摘要 |
PROBLEM TO BE SOLVED: To remove noises occurring at the time of raising and falling a power source by feeding bias voltage, corresponding to a signal and a power source and selecting one of a signal or a bias voltage in accordance with the state of the power source for outputting. SOLUTION: A switch circuit 11 supplies the output signal or a bias voltage Vbias of an input amplifier 3 to output amplifiers 4, 5 in accordance with terminals Te1 and Tc2. When the switch signal of the terminal Tc1 is at a high level, the switch signal of a terminal Tc2 comes to a low level and when the switch signal of the terminal Tc1 is at a low level, the switch signal of the terminal Tc2 becomes high level. The circuit 11 supplies the output signal of the amplifier 3 to the amplifiers 4, 5, when the switch signal of the terminal Tc1 is at a high level and the switch signal of the terminal Tc2 is at a low level, and the circuit 11 supplies the bias voltage Vbias to the amplifiers 4, 5, when the switch signal of the terminal Tc1 is at a low level and the switch signal of the terminal Tc2 is at high level.
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